# Driver for a MC-E



## videoman (Jul 30, 2009)

Trying to find a driver that can accept 7 to 15 volts DC that can run the MC-E at full rated output. A variable dimmer would be nice. Any drivers out there that have that? How could I configure it as I understand it has parallel, series etc?? Must run continously for 30 minutes minimum.


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## Fichtenelch (Jul 30, 2009)

Parallel or in series is the way to drive the 4 dies of the p7.

It depends on batteries and heatsinking if it can run continuously...

KD has a 2.8 Amp driver with a pretty wide input range i think. Click


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## phantom23 (Jul 30, 2009)

KD driver requires intense cooling because thermal protection cuts voltage very quickly.


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## videoman (Jul 30, 2009)

I was looking at that KD driver, how do you attach it to a heatsink as I do not see any really large flat surface on it? Also does the MC-E come in a star config so I can properly seat it in a heat sink ? Thanks


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## BeachBoy (Jul 30, 2009)

hipflex

http://www.taskled.com/hipflex.html


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## Gryloc (Jul 30, 2009)

I believe that it would be easy for you to drive the MC-E when wired in parallel if your voltage is going to vary that much. However, if you are certain that the input will be constant at a certain voltage, we may be able to wire the MC-E differently and use another variety of drivers. So below are some very nice drivers that will power the MC-E (or a P7) at its rated current if you wire all four dies in parallel:

From TaskLED, the HipCC and HipFlex will work great. The single-mode HipCC operates from 4.5V to 25V, and the HipFlex operates from 4.5V to 24V. The HipFlex has a really cool and smart user interface (UI) that gives you many options, from preset levels, to settable max current outputs. In addition, you can change the low voltage cutoff, auto-off time, and much more.

From the Sandwich Shoppe, you can choose from three different Shark Buck drivers. The Shark Buck operates from 4V to 24V (recommended by the creator in this thread). The Shark Buck contains a trim-pot so you can manually set the max current going to the LED (from nearly 0% to 100% of the max preset current). Three products are offered: each has a preset amount of current delivered to the LED(s): 1000mA, 2000mA, and 3000mA. You can remove this trimpot and add your own potentiometer (a variable resistor) that you can mount on the outside of the flashlight to change the output by the turning of a knob. 

So, if you go with either of the three above drivers, you will not be disappointed by the quality and/or features. There are a couple of other drivers around here that may work as well, too. As for the KD or DX drivers, I have no clue on the quality of these drivers, or how consistent they are on output current. I do not know if they are as efficient as these above drivers. I also think they do not have a big enough input voltage range for your application (others please chime in). With the three drivers above, you can get a heck of a lot of help by members of the CPF, and the creators of the circuits (just ask for the member names). You might be on your own with the KD/DX drivers.

Finally, with either of the three drivers I listed above, they are typical buck circuits (they drop the input voltage to power the emitters at the driver's designed current level). This means that as long as the input voltage stays above the forward voltage of the LED emitters (you need 0.5V to 1V overhead), you can drive any amount of LEDs in series at ~2.8A per LED! So with a input voltage of 7V, you may be able to drive two MC-E or P7 emitters in series, and up to four emitters if the input voltage stays around 15V.

Cheers,
-Tony


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## Justin Case (Jul 31, 2009)

Just looking at the workmanship of that KD driver would steer me away. And examining the series of product photos shows the in-line component changes that seem typical for these inexpensive Chinese drivers. In one photo, you see two SS34 Schottky diodes. In another photo, some other single diode is used instead (I can't read the writing on the component). And the inductor has no markings on it to indicate the inductance value. I've run into these Chinese drivers that probably use undersized inductors, with the result that the driver doesn't run reliably throughout its rated voltage range. They go unstable at upper voltages (and before hitting the max rated voltage).

I prefer to get a known, supported, quality product from The Shoppe or TaskLED. But I'm also willing to pay the money for that level of product.

That said, you have other options besides the Shark Buck, hipFlex, and hipCC, if dimming isn't a hard requirement.

You could wire the MC-E in 2S2P and use an SOB1400 to run the LED at full power. The main downsides are that the small SOB driver will need good heat sinking, running in full regulation at 7V is probably not going to happen (my guess is that you'll need at least 8V in), and you probably won't find a 2S2P MC-E on a star (4S and 4P MC-Es on a star seem common).

For an inexpensive Chinese driver, the KD SKU S002982 can be easily modified for 1.4A output (the stock driver is 1A out to drive a 2S2P MC-E at full power (I'm actually using one of these boards for this purpose). However, my bench power supply measurements suggest that the board becomes flaky above 12V input. The nice thing is that the board goes into full regulation at 7V and runs at about 90% efficiency between 7V-12V.

To do the mod, remove resistor R1 that is next to the AX2002 buck IC -- it is marked R220 in the images on the KD web site -- and replace it with an R560. For the empty resistor location R2, solder an R250 resistor, which will be in parallel to resistor R1. The resultant sense resistor value is 0.173 ohms, giving nominally 1445mA out.

I think if you replace the stock 22 uH inductor with a 33uH (or higher) version, the driver will run stably to its rated Vin max.


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## videoman (Jul 31, 2009)

Wow, thanks for all that info, My project seems to be getting along nicely.I have a couple of questions but I would like you to know first that I have located a source that makes black aluninium enclosures that are well suited for heatsinking and heat dispersion. I will be using a case that measures 3 inches X 3 inches X 4 inches deep and also has fins on it for heat dissipating.. This case must contain 2 led's with each led having it's own driver and that each led have(if possible) it's own dimmer control mounted externally behind the case.This unit would be powered from various power sources (DC) and types of batteries ranging from 6 volts up to 15 volts DC. The light will be used as a on-camera high output light for video purposes. Price to make is no object, I want the most reliable drivers, best led's for the job, best potentiometers out there and anything else that might be necessary to accomplish this.The main criteria is that it has an equivalent light output of a 100 watt or more halogen bulb, meaning that it has to illuminate a subject at 30 feet away with a horizontal evenly lit angle of no less than,60 degrees.If the P7's are better let me know, reliability is paramount. Later if this project is successful, I would like a smaller unit using 1 led (MC-E or P7) with a built in 7.2VDC li-ion. Many thanks for your great support and suggestions.


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## videoman (Jul 31, 2009)

I just read a thread on Custom and modified lights by Mick and he has a cave light that uses 3-P7"s in it with a hipflex driver.Wow, That's wat I'm talking about. He made this with a lathe and looks awesome.Now if that light can be dimmed with a rear mounted pot and those lenses can be floods. How reliable is the driver, considering that I will probably only need 2 MC-E's or P7's ?


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## videoman (Aug 1, 2009)

Checked out the hipflex driver and looks good. however how can I put an external dimmer (pot) outside the case to it, and what value ohms. Also I saw the luxdrive driver that is also nice and can be ordered with the dimmer. Question is, which one of these is more reliable to drive either the MC-e or ssc-P7 ? With the dimmer, is the color temperature going to change as it is dimmed ? Thanks


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## Gryloc (Aug 1, 2009)

Videoman,

The Hipflex has a great built in UI with several modes, but from what I read on the TaskLED's website, I do not see that it can be dimmable using an external potentiometer. The sense resistance is so low (less than a quarter of an ohm), that you will be unable to find a pot that even has a resistance that low (the ones I played with usually had a min of 1 ohm, and a max of 10 ohm, 10K ohm, 100K ohm, etc). Usually drivers that use very low resistance sense resistors are extremely sensitive to tiny changes in resistance, so any variable resistor that could work would be tricky to use. The same with the HipCC. These can be PWM dimmed, which means you may be able to make a very basic external circuit that will do this, or use a separate master driver. You can email the owner of TaskLED to see if there is certainly a way. He is very friendly and helpful. 

The only driver that would work with a parallel wired MC-E that is fully dimmable is the Shark Buck. With this one, you can attach a standard logarithmic potentiometer (50K ohm?), and dim away. These are one of the drivers that have a separate part of the circuit that varies the current (dims from 0-100%) using much higher values of resistors (and therefore potentiometers). There is still a part of the circuit that uses a low value sense resistor (it sets max current), hence the 1A, 2A, and 3A versions.

As for the Luxdrive drivers (which can be dimmed on some models), I do not see any drivers capable of delivering over 1A to the LED. If you wire the emitter in parallel, you need 2.8A delivered to the MC-E to drive each die at 700mA, and 1.4A if wired in 2S2P. This would only work if you wire the MC-E in series (in which then a 700mA or 1000mA driver could work). However if you do that, your battery voltage would have to be greater than ~13.6V (assuming around 3.4V per die at 700mA).

As for reliability, any of these drivers are golden (shark buck, hip- series, and luxdrives). These should outlast the LED (maybe not completely, but you may want to swap emitters several times to stay up with technology many times before the driver may have issues). Even if the driver starts to mess up or fail, either dat2LED (for the Shark) or Georges80 (for the TaskLED) will take care of you!

EDIT: Oh, I forgot to answer the post before. All three drivers I mentioned before will reliably drive 2 or 3 MC-E or P7 emitters in series. Just make sure the input voltage is high enough so the driver has the headroom it needs to dish out the designed current. TaskLED's drivers do operate more efficiently with more series connected emitters (look at my previous links). The Shark Buck still operates at more than 77% efficiency, which is great. These high quality drivers will last longer if they are happy and efficient. Since these are designed to deliver high currents to LEDs, then they will do so reliably. It is when you force other drivers to deliver higher currents, by just changing a few components on them, is when you get into reliability or stability issues...


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## videoman (Aug 1, 2009)

Hi and thanks for the detailed info. The configuration I have in mind is an aluminium enclosure with ridged heat sinking all around that measures approximately 3 inches diameter by 4.5 inches long.Using 2 MC-e's and each one with it's own dedicated buck driver with dimming control.Later I would have same enclosure with 3 MC-E's and 3 bucks. The seating of the drivers can be on a 3 inch diameter X 1/2 inch thick aluminum stock.The buck's can also be mounted likewise near the back. Using the 2 driver configuration for now, can I wire the 2 bucks off the same battery? I have 2 battery options, one is a 7.2V DC li-ion, the other is a 12 volt li-ion.Having 2 dimmers mounted in the rear, the only buck I see is the Lux drive ones. Any thoughts on improving the set-up?


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## videoman (Aug 1, 2009)

Checked out the Sandwich Shoppe, can,t seem to locate a phone number or address of them. Are they reliable ?, I just want to contact them for item availability.


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## Gryloc (Aug 2, 2009)

videoman,

Actually, if the battery voltage is high enough, you can wire two, maybe three, MC-E emitters (each wired in parallel) from a single driver. Those three drivers can deliver up to 2.8A, at any voltage necessary in order to keep delivering 2.8A, as long as the input voltage is higher than the combined Vf plus a bit more than 0.5V for the driver electronics overhead. This is how buck drivers work. They do not care what LED you put on its output, as long as they can handle the current, or if the Vf of the LEDs (at a certain current level) is not higher than the max voltage that the driver can output. 

How many li-ion cells are in that "12V" battery? I wonder so we can determine the voltage range during the life cycle of the cells. So, if you use the 12V li-ion battery, then you can easily drive both MC-E emitters in series (where all four dies in each emitter are in parallel) from a single Shark Buck using a single potentiometer. With the 12V battery, it would be a waste to power each MC-E separately with their own driver. It would also seem to be easier to quickly dim the light output up or down when needed using a single potentiometer.

I guess I did not understand what you are asking about the two potentiometers and the Luxdrive drivers. Just to clarify, the Luxdrive drivers may not be suitable for your application if you are only using 12V (V in is not high enough to wire the four dies of the MC-E in series to drive them at 700mA).

If you use the 7.4V li-ion cell, you may be able to drive the two MC-E emitters in series like above, but only if the forward voltage is low enough (the Vf does vary per LED as well as how other characteristics vary due to the manufacturing processes). It would be the safest to drive each MC-E with their own drivers if you use the 7.4V li-ion battery, just in case your MC-E emitters have a high Vf.

If money is no object, might as well use three MC-E emitters with the 12V battery. You would only need one driver, and one potentiometer. You do not have to drive the emitters at their max current. LEDs become more efficient as the current decreases, so three emitters operating at, say, 20W would put out more light than two emitters operating at the same power. If you demand a certain max output, then three emitters will allow longer battery life than if you used two. Finally, if you really need the performance, you can crank it to the max (as long as the case can handle the heat).

I hope that I do not sound pushy, but I would like you to be the happiest with your project. Professionals need the best tools. Anyway, the Sandwich Shoppe is perfectly legit. I believe that it is nearly as old as the CPF, and practically created for us as far I know. I have ordered from them many times, and were happy with the service. They responded to my emails helping me with any issues or questions I might have had. I always thought it was weird that they do not have a number listed, too. Well, if you have any concerns, just ask around. 

I hope what I said made sense. If not, just ask. Next time I need to start tossing in some numbers and math to clarify. These drivers can be set up so easily once you determine the LEDs used and how much current you want to send to the LED, how they are wired, and the type of power source.

-Tony


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## roguesw (Aug 2, 2009)

videoman said:


> Checked out the Sandwich Shoppe, can,t seem to locate a phone number or address of them. Are they reliable ?, I just want to contact them for item availability.



Yes, they are very reliable, they have been part of CPF since the beginning and many modders utilise their convertors , some people like McGizmo.
A lot of modified lights use their convertors for many years before KD came online.

I have a light that is built with a shoppe convertor and its pushing 6 years old now and still going strong.
Order from them with confidence.
They even have a subforum here on CPF in the modded section


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## Justin Case (Aug 2, 2009)

Gryloc said:


> Videoman,
> 
> The Hipflex has a great built in UI with several modes, but from what I read on the TaskLED's website, I do not see that it can be dimmable using an external potentiometer. The sense resistance is so low (less than a quarter of an ohm), that you will be unable to find a pot that even has a resistance that low (the ones I played with usually had a min of 1 ohm, and a max of 10 ohm, 10K ohm, 100K ohm, etc). Usually drivers that use very low resistance sense resistors are extremely sensitive to tiny changes in resistance, so any variable resistor that could work would be tricky to use. The same with the HipCC. These can be PWM dimmed, which means you may be able to make a very basic external circuit that will do this, or use a separate master driver. You can email the owner of TaskLED to see if there is certainly a way. He is very friendly and helpful.
> 
> The only driver that would work with a parallel wired MC-E that is fully dimmable is the Shark Buck. With this one, you can attach a standard logarithmic potentiometer (50K ohm?), and dim away. These are one of the drivers that have a separate part of the circuit that varies the current (dims from 0-100%) using much higher values of resistors (and therefore potentiometers). There is still a part of the circuit that uses a low value sense resistor (it sets max current), hence the 1A, 2A, and 3A versions.



hipCC can be controlled via the d2Flex PWM controller.

Besides the pot, you can add the Remora UI daughterboard to the Shark Buck for multimode control.


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## Justin Case (Aug 2, 2009)

videoman said:


> Checked out the Sandwich Shoppe, can,t seem to locate a phone number or address of them. Are they reliable ?, I just want to contact them for item availability.



If you go to the Shoppe's web site, you may run into problems with Google trying to block access because they report the Shoppe as an "attack site". The Shoppe's web site is legit and not an attack site. Their server got infected. See this thread for explanation.


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## videoman (Aug 2, 2009)

Tony, thanks a million for all the info. From what I understand is that I can drive the 3 emitters from the same buck with only 1 dimmer. The voltage supply is 14.5VDC tapped from a professional Anton Bauer Pro Video camera. These batteries are used for powering video cameras as well as having a TAP or Power Brick connector on them. For one type of video light that I am building, will take its power off of it. They are conservatively 
rated at 8000ma if that means anything. I imagine they are li-ion or better.These batteries are not cheap and typically go for 500 dollars each.Videographers usually have 3 or 4 of these fully charged for the event. They normally run a 50 to 100w halogen sucking somewhere near 10 amps. Keep in mind that the cameras are not cheap either, averaging 10 to 15 grand a piece. That is why cost no problem to build one. Tony, I don"t mind buying a driver for each led with a pot for each led for dimming. You say that underdriving them would be more efficient. How about 3 of them in the same enclosure, so if I underdrive them, they should have the same output or more as 2 at full capacity. Would I see any problems using 3 drivers as I am afraid that 1 driver can overheat, stressed ? Also I think that having them as 3 separate circuits can be more reliable as if 2 would shut down for any reason, the third can be used to at least illuminate the subject. Please correct me if I am wrong as I will be building approximately 100 of these type of units for our videographers. The other unit I am thinking about is a 2 led unit with a built-in battery and dimmer. Thanks


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## Illum (Aug 2, 2009)

videoman said:


> Trying to find a driver that can accept 7 to 15 volts DC that can run the MC-E at full rated output. A variable dimmer would be nice. Any drivers out there that have that? How could I configure it as I understand it has parallel, series etc?? Must run continously for 30 minutes minimum.



full rated output would be 350ma per die, maximum rated at Iled = 700ma
Assuming your power supply is DC...all you would need is to wire your MCE emitter in series by either using individual hookup wire or a series connected LED star. 

Since this is posted in "beyond flashlights" I'm assuming this is for fixed lighting or any other purposes that the recommendation will not be constrained by the ability of it to fit in a flashlight...

MCE wired in series would yield 3.2x4 = 12.8V, your DC power supply may not be adequate as some buck [step-down] converters require minimum of 16V input for 4 LEDs [such is the case IIRC with the LuxDrive power puck].

I'd recommend the LuxDrive 4015 BoostPuck [Datasheet here] available from www.Ledsupply.com, there may be other alterenatives to choose from. Note that the boostbuck stated above is limited to Iled = 350ma


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## videoman (Aug 2, 2009)

Hi and thanks for a quick reply. Perhaps I am confusing the issue with 3 led's in a fixture. It is not a flashlight. It is an on-board video light with 3 led's with 3 drivers ( one driver dedicated to a led) with 3 dimmers ( one dimmer dedicated to a driver) in other words it's like having 3 redundant units in case one or 2 fails. The only common thing is that they will be powered from the same battery 14.5 VDC rated at 8000ma li-ion. Can this be built ? Cost or money is absolutely not a problem.Reliability is the key factor. Thanks


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## Gryloc (Aug 2, 2009)

Illum,

I guess that the thread changed around a bit since the original post. There was a lot of things discussed since (and I made many lengthy posts lol). Sorry for any confusion. 

So far we were discussing driving 2 or 3 MC-E emitters from either a single driver, or individual ones (for each LED) with a single, or multiple potentiometers for dimming capability. 

videoman, could you post more details about this monstrous battery? Is this the same battery as the 12V one you were talking about a few posts ago? Just curious. Lli-ion cells usually have a nominal voltage of 3.6 or 3.7V (same thing) and a max voltage (when fully charged) at or slightly less than 4.2V. So I am wondering if this battery is using 3 or 4 li-ion cells. Whether this batter uses 3 or 4 cells affects maybe how and what you can drive...

I will post back in a moment when I get my thoughts organized. I am going to use some lumen and voltage data from jtr1962 and toss together some ideas I had -some different scenarios.

BTW, since the cost for a driver per LED for redundancy does not bother you (which is cool since this is for a professional lighting device), then what if you make this light that is somewhat modular so it can accept additional LED/driver combos that attach to each other and share the same battery? Each module can have a potentiometer, or maybe you can tie the multiple drivers together in order to share a single potentiometer (for ease of dimming equally). If size and bulkyness is an issue, then maybe a single machined enclosure can be used to make a two or three LED light (capable of handling the heat of the worst case scenario). Later... 

-Tony


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## videoman (Aug 3, 2009)

Hi Tony and thanks for a quick reply. The battery used on our video cameras is the Anton Bauer model DIONIC 160 which has the specs as follows:14.4V DC Li-ion rated at 160 WH. weighs in at nearly 4 lbs. How many cells are in there ? Idon't know. I can crack one open and see. Money no object. Thanks Tony


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## Gryloc (Aug 4, 2009)

videoman,

Please do not open one of the batteries. It would be wasteful. I needed to know how many cells are in series in that battery, and since you say it has a voltage of 14.4V indicates that it uses 4 cells wired in series. Most likely, this uses large, or numerous, cells wired in each parallel bank; and these paralleled cells are finally wired in series to make 14.4V at many mAh or Wh. Great!

Okay, I have been too busy to come up with a post of scenarios, but I made an excel spreadsheet to determine the potential luminous flux of an MC-E emitter. It also shows the Vf of each die at a certain level of current (these variables are dependent on each other). In this chart, I used a sample LED that had a Vf that is slightly above average throughout its entire range. I have seen emitters that have a forward voltage from 3.3V to 3.6V at 700mA of current. The sample I will use in a simulation has a Vf of 3.51V at 700mA. This will give us a little slush room in case you get MC-E emitters with a somewhat high forward voltage.

This data is from jtr1962 in this thread. I have compared several emitter samples from him and me (I can only test Vf accurately, but he can measure every property of a LED including luminous output). I have found that most have a similar relative output ratio that is very close to the ratio curve of this R2 XR-E sample. This ratio is found by dividing the amount of lumens at XX current by the amount of lumens it produces at 350mA. Since many LEDs share a similar ratio curve to this, I will assume that the MC-E emitters you will buy will be just as similar. So, these MC-E emitters are binned at the factory when each emitter is driven at 350mA. I directly compared the lumen output to this ratio. I plugged the binned total output at 350mA in to the output ratio of 1.000, and interpolated from there.

In the screen capture of the table below, I also showed what would happen if you wire each die in parallel or series. Just remember this: LEDs wired in parallel divides the total current between each die, while the voltage is the same as that of a single LED; LEDs wired in series divides the voltage between each die, while the same current passes through each die. So 4 LEDs with a Vf of 3.5V at 700mA are wired in two ways: in parallel, the Vf is 3.5V at 2800mA; in series, the Vf is 14.0V at 700mA. Click on the picture for a full sized table:






Think about the properties of a quad die MC-E and how closely they act like 4 separate emitter. You can determine how many LEDs you will need to get the desired total output after seeing the luminous flux of the cool white, neutral white, and warm white emitter options you have. I chose the best of each type (tint) of MC-E available at Cutter Electronics. 

Think about it, and I return later with more info on possible scenarios using actual numbers. It should be more comforting than saying something like "3 of these will work if you drive them at XX current... I think."  I am not worried that the output will not be enough, I am worried how the voltages will work out, and that the wiring configuration and driver selection works the best for you. Efficiency, simplicity, and features are important. I am hoping others will contribute to come up with more scenarios.

Cheers,
-Tony


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## videoman (Aug 4, 2009)

Tony, thanks a million. That is quite a bit of useful info. Just your opinion on one thought I had in mind.Say I am looking at ONE MC-e. If I have one MC-E in parallel die config. that would mean I can use a shark buck (not boost) as the input voltage(14.4) would be higher than 3.6 or so. and if it is config. in series, then all the 4 dies together need 14.4V , it would be same as the input 14.4V. Would that be OK for the buck? I was also thinking that underdriving the MC-E at say 75% would make it more efficient. The componets I am considering are: Three-MC-e's( in neutral white) Three Shark bucks (as they can support an external logarithmic pot) for dimming. One-3ganged logarithmic pot ( to control simultaneous dimming of all leds).Question: what is a good pot wattage and value to use?Also if I have the MC-e(Dies) in parallel, would I also have the option to use a 7.2V battery ( li-ion 6A ) ? since the Voltage is high enough.The 7.2V option is not necessary for now.So here is my scenario: 3 led's each with it's own driver, each driver with it's own pot , and one huge 14.4 V DC batt to supply 14.4V to each driver(all drivers connected in parallel to batt).What would be advantages/disadvantages of having the dies in series? I will take care of heat, cooling, case design, and wiring later. Thanks Tony


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## Gryloc (Aug 4, 2009)

I looked at the datasheet for the “Anton Bauer DIONIC 160” (see here), and I found that the battery has voltage range from 12.4V to a max of 16.4V (which is rather conservative), and has a nominal voltage of 14.4V. This is probably the supported voltage range of the internal electronics, so it is best to stick with this range. So, the driver has to be able to handle a no more than 16.4V, and the voltage needed to run the LEDs, plus the ~0.5V overhead needed for the driver, probably should not exceed ~13V, or maybe less. If the battery voltage drops below the min voltage needed by the driver and LEDs, then the driver will drop out of regulation as it may go into direct drive mode. The LED will probably begin to dim noticeably as this happens. You should be able to dim the LED down further with the potentiometer, but you begin to lose your upper brightness range as the battery voltage continues to drop. 

This slight dimming or a loss in the upper brightness range might be desirable to indicate that the battery voltage is about to reach the range when the internal electronics will begin to completely cut off. It would act like an early warning for the user. If you will watch the battery status closely or if you do not want this small, but uncontrollable drop in output, then maybe you should have the maximum voltage of the LEDs and driver stay at, or slightly below, 12.4V.

So, the following scenarios will allow you to drive the MC-E emitters at 700mA per die. At this current level, expect around 639 lumens from a single neutral white MC-E. At half the current (350mA per die), expect 370 lumens minimum (the MC-E was rated and binned at this current). Looking at Wikipedia on an article on incandescent bulbs (here), it states that a 100W 120V bulb produces 1700 lumens of output with an efficiency of 17 lm/W. I am not sure how premium, high performance halogen bulbs compare in terms to performance and efficiency to these typical 120V household bulbs. If we use this 1700 lumen number, then we will need at least 3 MC-E emitters (639 * 3 = 1917 lumens). Two would output 1278 lumens. Driven at 700mA per die, each MC-E emitter will consume 9.83W, and have an efficiency of 65lm/W. This will mean a big power savings compared to the inefficient light bulbs.

Scenario #1:
Like I mentioned before, you can wire the four dies in the MC-E in parallel, and power it from its own Shark Buck. From the chart in my previous post, look at the voltage and current ranges of the “4 dies in Parallel” columns. Notice that if you want to deliver a maximum amperage of 3.0A (750mA per die, theoretically), then the Vf of the LED will be a total of slightly more than 3.51V. Let us say you want to dim the output until each die sees 350mA (1400mA total when in parallel), then the Vf will be 3.31V. If you drive the LED at 3A (3.5V), and the Shark Buck (3A model) driver needs, say a conservative 1V for overhead, then you can use any battery that has a voltage ranging from 4.51V to 24V. The 7.2V li-ion battery you mentioned before would have a operating voltage range from ~6V to 8.4V, so you can use either battery with this light fixture! With the Anton Bauer 14.4V battery, you will maintain the capability to dim the LED from nearly 0% to 100% regardless to the battery voltage, even when the battery is about to fail and cut-out. 

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Scenario #1 Value:
This is the same scenario as above, but you use one Buck Shark 3A model to drive three MC-E emitters in series. Each emitter has its dies in parallel. if you want to deliver a maximum amperage of 3.0A (750mA per die, theoretically), and there are three MC-E emitters in series, then the Vf of the LEDs will be a total of slightly more than 10.53V. Let us say you want to dim the output until each die sees 350mA (1400mA total when in parallel), then the Vf will be 9.93V. If you drive the LED at 3A (10.53V), and the Shark Buck (3A model) driver needs, say a conservative 1V for overhead (but should be close to 0.5V actually), then you can use any battery that has a voltage ranging from 11.03V to 24V. You can definitely use the 14.4V battery and still be able to dim the LED from 0% to 100% throughout the entire life of the battery. The 7.2V battery could not be used in this situation (unless we make another scenario like this one where only two MC-E emitters are wired in series). The Shark Buck will not be troubled with the fact that it is now driving three MC-Es at full power, except the driver will have to dissipate a bit more waste heat.

Scenario #2:
This scenario may be less ideal due to how the LEDs will act during the life of the battery. You can wire the four dies in the MC-E in series, and power it from a different buck driver circuit. The Lux Drive circuits support dimming via an external potentiometer. A Shark Buck may not be suitable for this purpose unless you use the 1A version. From the chart in my previous post, look at the voltage and current ranges of the “4 dies in Series” columns. Notice that if you want to deliver a maximum amperage of 750mA per die, then the Vf of the LED will be a total of slightly more than 14.04V. Let us say you want to dim the output until each die sees 350mA, then the combined Vf will be 13.24V. With 750mA delivered to each die, the voltage will be 14.04V, so with an overhead voltage of 0.5V (actually I do not know what overhead is needed for Lux Drive drivers), then you will need a battery voltage of about 14.54. This means you can use any battery with a voltage range of 14.54V to 24V. This eliminates the capability of the circuit to work with your 7.2V battery. This cuts significantly into the voltage range of the 14.4V battery, so that means that about halfway in to the life of the battery (when the nominal voltage is 14.4V), the LED will already start to dim a bit. To show how much, we will do a bit of quick math…

Okay, so 14.4V minus 0.5V for overhead means that the LEDs will be getting around 13.9V. If you divide this LED voltage by four, you get 3.475V. Each LED will see 3.475V, and therefore, will only draw around 600mA. The output would decrease by about 11%, compared to a full capacity, by the halfway point. By the time the battery reaches 13V (the cutoff point is 12.4V), then each LED will see 3.125V (12.5V / 4), so each die will only draw around 150mA. At this point, the max output would decrease by about 72%, compared to when the battery was at full capacity. I can see that this scenario will really limit what you can do with your light. The only advantage is that the LEDs will automatically dim at a slow steady rate as the battery voltage drops, which will boost runtime significantly (if you can live with a dramatically reduced output). 

Scenario #3a:
This scenario may be a bit tricky, but completely practical. This scenario will allow you to slightly overdrive your MC-E emitter for those strange moments, or maybe emergencies, where you need that extra output (dark outdoor moments, or whatever) if you do not mind sacrifice runtime a little. With this setup, you will be able to drive each die at 1000mA versus 700mA. With the neutral white emitters, you may see an increase in output by up to 28% (822lm at 1000mA versus 639lm at 700mA for each MC-E). The LEDs will run a bit hotter as well, so you may have to design a larger fixture to dissipate this heat. If you use a fixture designed for an MC-E powered at 700mA per die, then you could still power the MC-E at 1000mA per die for a short while, but maybe not for prolonged use. 

Here is how it works. You will wire the four dies of the MC-E in a series/parallel configuration. This means that you have two sets of dies wired in series, where each set has two dies wired in parallel. We refer this to 2S2P at the CPF. This means that for each die to see 700mA, then you have to deliver 1400mA (because the current is divided by two), and as a result of the series wired die sets, the combined voltage will be 7.02V (the voltage will be divided by two). This opens some interesting doors. You can use different drivers as well. However in this scenario, we will use a Shark Buck 2A model, meaning that the maximum current that the Shark Buck will output is 2000mA versus the 3000mA of the models used previously. Since the current will be divided by 2, then the 2A version of the Shark Buck will be able to deliver around 1000mA per die. 

With only 700mA delivered to each die, then the Vf will be 7.02V. The total power consumption of the LED would be 9.83W. This means that you can use a battery with a voltage range of 7.52V to 24V. The 14.4V battery will still work perfectly with this setup, allowing you to dim the emitter from 0%-100% during the entire life of the battery. For the 7.2V li-ion battery that you mentioned before, the LEDs will start to dim about halfway in its life (the 7.2V battery should have a voltage range of 6V-8.4V with a nominal voltage of 7.2-7.4V). Using the dimmer, you would not be able to set it to 100% output since the input voltage is too low. This is sounding similar to Scenario #2 with this 7.2V battery. Now what if we overdrive the LED to 1000mA per die? 

With 1000mA delivered to each die (2000mA total), then the Vf will be 7.26V. The total power consumption of the LED would be higher at 14.52W. This means that you can use a battery with a voltage range of 7.76V to 24V. It would not be practical to use the 7.2V battery when overdriving (since it will be unable to do so for that long). However, you can still use the 14.4V battery and dim the LED so the current varies from nearly zero to 1000mA regardless to the battery life status. This scenario gives you a little added flexibility with the output of the LED, but takes from the flexibility of battery types.

Scenario #3b:
This scenario is nearly the same as #3a, but instead, we use a 1000mA max buck driver. This allows us to use the Shark Buck 1A model, or a 1000mA Lux Drive driver. The LED dies are wired in 2S2P like before, but the driver can only deliver a max of 1000mA, or 500mA per die. The voltage range will be about the same (cutting in to the voltage range of the 7.2V battery, but not the 14.4V battery), but the total output will be less. At 100% output, the neutral white MC-E will produce only 493 lumens (about 23% less output than when the dies see 700mA each). This scenario will allow you to use the Lux Drive driver if you ever decide that the Shark Buck is not for you. However, this scenario leaves you with less flexibility with max output and battery types, but I guess it does boast a higher efficiency at 100% output. You can use Scenario #1, #2, and #3a and just dim it so each die sees 500mA each if you want that efficiency, but in Scenario #3b, you are stuck with 500mA as the max output.

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So, you have in essence three scenarios. Each has its advantages and disadvantages. Scenario #1 stands out as possibly one of the most flexible, allowing you to dim the LED fully using either the 7.2V or 14.4V battery. Scenario #3 may be the most versatile as it allows you to deliver more current to the LED to increase output for those special situations. Scenario #2 and #3b may be less desirable, but it allows you to use another driver besides the Shark Buck. It has its shortcomings in terms of function (limits max output depending on the battery used).

Remember that if you can live without a potentiometer dimming, then TaskLED’s HipCC and HipFlex will work as well. The HipCC is only a single mode driver (on or off), but the HipFlex has a really nice UI to allow different modes. However, the modes are preset and may not be what you would like. However, if you can speak with George from TaskLED, he may be able to help you add a PWM dimmer to either driver to allow you to dim it (maybe with a potentiometer). The simple PWM circuit I think about is your easy to build “555 timer” dimmer. It uses a cheap and common “555 timer” IC to produce a pulse signal (PWM) that can be varied with the same kind of potentiometer that you would use with the Shark Buck. Used with either one of the two TaskLED drivers, you can easily dim the output just like the Shark Buck. 

Finally, regardless of which driver you use, it would be useful to know how much the entire circuit will draw from the battery. This will be useful to determine how much runtime you will obtain. Most of these Buck drivers operate at a relatively high efficiency (meaning that with any driver circuit, there will be some power used by the driver), and the Shark Buck operates at around 78% efficiency when you drive a single MC-E in series on its output. I am not sure if the efficiency increases any as you add more in series, so we can continue to assume an efficiency of 78%. This is the rule of thumb: (Vin * Iin * Eff) = (Vout * Iout). So, if you drive a single MC-E emitter at 700mA per die, then expect it to consume about 9.83W (0.7A *3.51V *4). Then the driver and LED combo would actually consume 9.83W / 0.78 = 12.6W. This means that the driver would consume about 2.77W of power. If you drive a single MC-E emitter at 1000mA per die, then expect the LED to consume about 14.52W (1.0A *3.63V *4). Then the driver and LED combo would actually consume 14.52W / 0.78 = 18.62W. This means that the driver would consume about 4.1W of power. Just use the chart to determine the total LED power (V * I), then divide that by 0.78. Then , you can divide the amount of Wh of the battery by the total W of the LED and driver combo to get an approximate runtime in hours. You can divide the input power by the input voltage to get the input current (it may help to determine fuse or protection circuitry ratings). So, your 160Wh battery would run a 12.6W load (700mA per die) for nearly 12.7 hours. Wow! With three MC-E emitters and drivers, then expect approximately 4.2 hours of runtime. With 12.6W input and 15V input, then the input current would be 0.84A. It is normal how as battery voltage drops, then current in increases. 

If you have more questions, just ask… 


Cheers,
-Tony


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## videoman (Aug 5, 2009)

Tony, I now see the many options available. I am sure that there are reliable suppliers that ship within and to US of needed components. I also want to be able to obtain the parts at a later date in case of repairs or to make more units. Dimming is important but not an absolute requirement. If it can be done, fine, if not how about 3 independent switches to power the led's on and off so that I would have one, two or all three. I would say 70% of the time 2 led's would be on , 20% 1 led would be on for short distances as interviews and close up objects and 3 leds on 10% of the time for short bursts would be at those long distances in a dark reception where we cannot get in close. Tony, I think that a 2 led setup will suffice to compare at what we are used to in halogen output, but because I want to offer a bit more flexibility and power when needed along with reliability. The videographers can use switches as needed, they have been doing that on their broadcast cameras for ages. The dimmer would be nice though, and perhaps can be added later in conjunction with the switches. For now let us forget the 7.2 battery option as that is a different design altogether that has 2 leds AND the battery in the enclosure ,for the other videographers that do not use the 14.4 V system. Option #1 ,I see as a good choice with a shark driver powering the LED ( parallel or series, what do you think?) at full rated( or less, what is your opinion on this?) output. The enclosure is at the design stage right now and is in freehand sketch, however the final design will depend on the components necessary and any added switches, pots, fuses etc. Now my question is where do I order my components? Cutter for the leds and Taskled for the drivers or perhaps you have any suggestions if they have no stock for now. I am planning to have at least 4 units ready for evaluation within the next 3 weeks. As to the other scenarios you have suggested, I leave it up to you to decide if you think that #1 is not the right choice. Thank You


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## BeachBoy (Aug 5, 2009)

I just learned a bunch in this thread, thanks for all that info!


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## Gryloc (Aug 5, 2009)

videoman, 

I felt that the first scenario would be your best bet. With this scenario, each MC-E must be wired in parallel because the driver is capable of dishing out 3A of current with ease. If you send this much current to a regular single die LED (or just to a single die on the MC-E), then you most likely fry the emitter, if not over heat it. So, when in parallel, the current is divided by four to each die. The dies will be comfortable with only about 750mA being delivered to them. The MC-E is has a max rated current of 700mA, but can still happily handle up to 1A per die with sufficient heatsinking. So 750mA would make the MC-E run at about full throttle (what you wanted). Do not worry about the extra 50mA, as it is really insignificant. Do not worry about underdriving them in a calculated way at this moment. Just get used to what percentage is needed during normal use (it may be 90% for one application and only 25% for another). Since these are very bright, you may run them most of the time at under 100%, so you will be underdriving them unconsciously. Even at full power, they are pretty dang efficient (especially compared to your old halogens)!

I am sensing that you have some doubts about the Sandwich Shoppe. You said that you will get the driver from TaskLED. Both Dat2zip (the creator of the drivers sold at the Shoppe), and Georges80 (creates the TaskLED drivers) are somewhat small scale manufacturers (they are huge here at the CPF) and will treat you the same -as the most important customer. I think that both of them send out large batches, and work on special projects for customers that sometimes are not available to the average CPF members. You will have to email or PM both to see who is capable of meeting your demands when you begin to build all of your camera lights. Both should have dozens of drivers in stock now (you can still check) for your prototypes. Both are located in the US, and they both ship pretty quickly. The MC-E emitters may take a little more time since they ship from Australia (from Cutter Electronics). 

Digikey.com also sells the neutral white MC-E, but they only offer the 320lm @350mA per die bin, while Cutter offers the 370lm @350mA per die bin (the one used in the above table). Digikey's MC-E also costs around 50% more that what Cutter sells them at. Regardless, I would reccomend that you buy the emitters now from Cutter so you can get them in a week or two. I am sure that the MC-E is the ideal emitter at the moment...

With Scenario #1, the dimmer should be easy to use from the very beginning! It is a piece of cake to use with the Shark Buck, but I am not sure if a homemade and separate PWM circuit (adjusted with a potentiometer) will work with the HipCC or HipFlex. This would be a good question to ask Georges80. As for the value of the potentiometer, a standard logaritmic 50K ohm pot should work with Shark Buck, and should also work with the PWM circuit (my "555 timer" circuit used one). I cannot tell you where you should get your hookup wire Radio Shack has really cheap quality wire, but you might be able to buy cheaper, but higher quality stuff online. Digikey or Mouser will have these odd and end electronics parts. If you need help procuring these parts, I can look online and create a list with links for you. Both Mouser and Digikey are the bomb! BTW, McMaster Carr sells raw materials (every type of metal, plastic, and rubber) at relatively convenient pre-cut sizes and shapes, and the prices are pretty decent (and shipping is light speed if you are near a distribution warehouse). McMaster also sells just about everything else under the sun that a company may use (from every sort of hardware, to tools, to safety equipment, to odd and end parts hard to find elsewhere). I would be happy to help you make component and material choices... 

You could use switches on each light in addition to the pot, so you can dim the lights on the fly, or instantly switch on or off the entire circuit with the flip of a switch. Both seem practical, as it gives you that extra control over your light. What do you think now?

-Tony


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## videoman (Aug 5, 2009)

Thanks Tony, I will order from Cutter and use the taskLED drivers. Which driver model is the one to use? hipCC or the hipflex ? as do you think I will need the flex model for current limiting? Also from Cutter, they have the MC-E's in neutral white but the mount is sold seperately, no problem with that, but is the star mount or round mount already soldered/glued to the led when I get it or do I need more than a soldering gun and solder to put it together? I know that I will need other stuff as I go along but for now I need the components themselves so that I can measure them for a custom heat sinked housing. As for switches and dimmers, that will be calculated into the design dimensions. If you have any suggestions Tony, feel free to contact me. I am on the computer 11 hours a day.


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## snarfer (Aug 5, 2009)

Just a couple things you might want to think about:

(1) PWM vs Constant Current dimming: generally manufacturers of lighting for film and video production avoid PWM dimming due to possible flicker, especially when shutter speeds over 30 fps are to be used.

(2) CRI: At 75 for Cool White and 80 for Warm White and Neutral White, the MC-E has a relatively low CRI compared to other LEDs. This may be an issue for film and video production purposes, especially when using the light to supplement daylight or existing tungsten sources. You might consider a larger number of smaller, higher CRI LEDs instead.

(3) Driver Efficiency: I believe you would get the highest efficiency by using a single boost driver and configuring all three LEDs in series, for total Vf of 42 volts at 100%. This is within spec for a number of off-the-shelf drivers.


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## BeachBoy (Aug 5, 2009)

videoman said:


> Thanks Tony, I will order from Cutter and use the taskLED drivers. Which driver model is the one to use? hipCC or the hipflex ? as do you think I will need the flex model for current limiting? Also from Cutter, they have the MC-E's in neutral white but the mount is sold seperately, no problem with that, but is the star mount or round mount already soldered/glued to the led when I get it or do I need more than a soldering gun and solder to put it together? I know that I will need other stuff as I go along but for now I need the components themselves so that I can measure them for a custom heat sinked housing. As for switches and dimmers, that will be calculated into the design dimensions. If you have any suggestions Tony, feel free to contact me. I am on the computer 11 hours a day.



taskLED is out of hipCC until early september.. I just bought hipflex instead, but they are $11 more expensive.


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## Gryloc (Aug 5, 2009)

Thank you, snarfer, about the tip on PWM. I forgot that drivers with built on trimmer potentiometers actually just reduce the current going to the LED by adjusting the sense resistance (and it is the switcher chip that is reducing current). I don’t know why I assumed that drivers with dimmers use something as crude as PWM. It snapped in my brain my experience with using a PWM only LED driver called the d2dim (by TaskLED), it uses only PWM to dim the LED, as it does not regulate current one bit. When Trying to get a picture of the LED die on a lower mode (lower % duty cycle of PWM), my digital camera struggled to focus on the die, and a flicker was apparent when using the video mode. Even slow shutter modes had issues catching the LED when it was actually on. Maybe modern video cameras my fare better with flicker, but videoman, I would not recommend using PWM. I wish I remembered this before getting enthusiastic about it. Sorry about that.

videoman, I guess you did not say why you are disliking the Shark Buck. Is the Shoppe's website too frightening to you? You may be able to buy the driver directly from dat2zip (i dunno, so email or PM him). I would feel more comfortable if you used the Shark Buck compared to the HipCC or HipFlex. The Shark Buck will dim the emitter without an apparent pulsing.

snarfer, videoman thought that redundancy would be nice to have by using a single LED driver per MC-E emitter. If a single MC-E was wired in series, then a boost circuit could not be used with 4 li-ion cells where when fully charged, the Vin would be higher than the combined Vf of the LEDs.

So, videoman, could I ask if you would mind powering two MC-E emitters from a single driver. Maybe if you could use this emitter in multiples of two, then you can wire two MC-E emitters in series (with the individual dies wired in series). This would result in a Vf of 28.08V. This would mean that a boost circuit, like the Shark BLUE (a boost, not buck) to drive two emitters from a 14.4V battery. The Shark Blue driver can drive LEDs with a forward voltage of ~14.4V (or whatever the battery voltage is) to 32V. The Shark Blue still uses a trimmer that can be replaced with a potentiometer, just like the Shark Buck. The Shark Blue can deliver up to 980mA (you can set the max to 700mA if you want, or not to keep it flexible) to all of your LEDs in series. There is a limiting factor (total output power versus input voltage), but if you don't understand, then I will just steer you away from it if its a problem. The max input current of the Blue Shark is 4A. So, 28.08V out * 0.98A = 27.5W. (27.5W / 0.8 ) / 14.4V = 2.39A input (safe). I can explain more about the properties later on if you would like a clarification.

Ok, so with two MC-E emitters powered by a single Shark Buck, you can dim the LEDs from 0%-100% through the entire voltage range of the battery. It says on the Shoppe that "The trim pot can be removed and an external 20K pot can be hooked up allowing control of the 
converter board", so that is the value of pot you would need. BTW, when you order any LED from Cutter, and you select a MCPCB star/round board with it on the same group of drop-down boxes, then the LEDs will be pre-attached to the MCPCB boards! Only if you order the stars completely separate (they are offered without LEDs entirely), then you would have to attach them. Just select a star board any you will be pleased with the product. If you did want to attach an emitter, you would have to reflow solder the components, which either requires expensive equipment or being very intuitive (I did it without pro equipment).

Next good topic: color rendering. I ignored this a bit because I was not sure how important it will be. If this is a fill light during the daytime, or when the lighting conditions indoors is not that bad, then I wonder what color rendering will do to the faces or clothing of the persons being filmed. I understand that most LEDs are not ideal for color quality, so I am assuming that the efficiency of using LED lighting with the long runtime outweighs the disadvantage of not rendering some colors as well as inefficient halogen lamps. So, videoman, if you want, you can use separate LED emitters that will render colors better, but all it will mean is a few extra wires to solder. The separate LEDs can be wired just like the dies in the MC-E... actually you might have more flexibility with separate LEDs (you can run three in series where you are stuck wiring either 1, 2, or 4 in series with the MC-E. Another idea is using the addition of colored LED emitters to fill in the color deficiencies that the MC-Es posses. BTW, there are high-CRI LED emitters created by Seoul Semiconductor, and Lumileds is about to release a line of LEDs that give you the choice between NINE varieties of LEDs that have different color temperatures and CRI values to choose from. These CCT/CRI specific LEDs will be available by the end of August or early September, according to their supplier (I personally called a week or so ago). The light from these will make the light coming from your current LED flashlights look like cheap keychain lights or toys (in terms of color, not necessarily output). Finally, you might be able to design a halogen/LED hybrid light that still gives you the choice of using the old halogen for rendering colors well with a sacrifice of runtime, or flip over to highly efficient LEDs. Maybe you can mix the two (40% halogen, 60% LED or something) to increase both efficiency by a little, while still rendering colors pretty well.

So, videoman, how critical is color rendering. I think it would not hurt to hold back on you prototypes until you can see what the LED light (tint, apparent color rendering) looks like for yourself before diving in. Consider if your customers will be okay with sacrifices in color rendering.
I am sorry that after almost reaching a level in confidence or comfort in a selection of parts, I say all of this. Definitely, PWM will be an issue regardless to the LEDs, so the Shark Buck or Blue will be ideal dimming is still a great feature I would try to keep as it will give your product that useful edge). The color quality of the light is something to think about. Finally, think about the possibility to use a single driver to power two or more LEDs. LED drivers just don’t fail on you. This is a very important application, but if one would fail, then it will not affect anyone’s life. Money saved on these expensive drivers could be spent on high CRI LEDs, or other luxuries.
Again, sorry for shifting so much on you. I tried my best and there are a lot of people out there with good ideas, or a great eye on things that are missing. My long posts may be too off-putting to some to want to contribute. To be honest, I got really excited about your project in your past, and I kept in mind that desired three week date. I hope the discussion becomes more lively in here (besides us two most of the time). Thanks. oo:

-Tony


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## videoman (Aug 5, 2009)

Thanks everyone for all the valuable information. Perhaps I did not fill you in with enough information on our video production ways and techniques. I myself have videotaped and photographed well over 3000 weddings in a span of 38 years. There is really nothing ideal about this profession as everything and I mean everything changes and is never what a cameraman wants it to be. It is one of the tough jobs here on earth and luckily I am retired from it, but I still active in helping others to make their work a little easier and better. As nothing is ideal especially the given the light sources that we have to accept and deal with it. There are cloudy days, rainy days, warm end of day yellow tint and long shadow days, all that must be captured and later adjusted in post production. We strive to get the colors right as we shoot but there are times that the colors just have to be corrected because if the bride's dress is white, she does not want to see it light beige.No, color CRI really would not be a big issue as any color shift can be corrected in Final Cut Pro. As for frames per second, we shoot mainly in 24P mode or 24 frames/sec. and only a few of us shoot at 29.95 fps. We never shoot over 30. As far as the time frame to complete this project, it can wait, as I wanted the guys at least to have a hands on trial for the upcoming 2010 season. The video shooting ( I would like to say "video taping" but who uses tape anymore?) is done with 3CCD broadcast grade cameras by Sony and Panasonic and recorded onto either HD (hard drive) or onto memory cards. Yes there are LED video lights out there available but their brightness leaves a lot to be desired. Believe me I tried all of them and the build , features, battery options, powering requirements etc. did not cut it. So that is why I want to do this, also because it gives me something to do besides looking in a camera. On reviewing the suggestions about the Shark driver and it's capability of a dimmer, I will consider the option as well as using a different wiring set-up as suggested. At least now I understand that designing a seemingly simple light, there is much more involvement than first imagined. Later there are other considerations to take into account such as diffusion, light dispersion to cover a wide angle with no hot spots, etc. but I will deal with that myself. I will have a case design with heat consideration within a week and will be happy to show it once finished.
Again, your help with this project is greatly appreciated.


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## aljsk8 (Aug 6, 2009)

not to hijack but im doing a very similar setup for floodlighting areas of skateparks at night

my current setup is 9 xre p4 cool white and is a direct drive resistored setup from a 12v sla (12a)

im going to upgrade to 3 or 4 mce neutral white and wanted to use a driver for better control of heat and runtime

the info on this thread has been very helpful

thanks


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