simple high/low drop-in for Arc LS

Re: simple high/low drop-in for Arc LS / L4

I expect Mr. Bulk to be too busy for a while due wrangling the VIP logistics. That's a good thing. /ubbthreads/images/graemlins/smile.gif

Glad they got there OK. I worry that some postal inspector will see springs and things (in an envelope) on an Xray machine and send the Homeland Security guys to my house for a little talk. Nah, not really, but I can see them delayed if the springs trip a metal detector.

Have fun with them guys.

Daniel

P.S. Mr. Bulk has already paid me back; He put me on the list to buy one of his new VIP models.

Re: simple high/low drop-in for Arc LS / L4

Got my mail from Daniel today - WOW - Thank you very much and again I want to propose this for the gadget / mod of the year ! It also works nicely on other Kroll-equipped lights (like my 2AA/3AA bodies driving SF KL1/KL4 heads) and should work fine on Mag/Sandwich/Kroll combos too.

Klaus

Re: simple high/low drop-in for Arc LS / L4

Daniel,

Thanks for sharing the details of this mod with us all. What a great idea. I made a couple of these this weekend and they work awesome. They weren't as hard to make as I first feared.

Re: simple high/low drop-in for Arc LS / L4

[ QUOTE ]
Klaus said:
Got my mail from Daniel today - WOW - Thank you very much and again I want to propose this for the gadget / mod of the year ! It also works nicely on other Kroll-equipped lights (like my 2AA/3AA bodies driving SF KL1/KL4 heads) and should work fine on Mag/Sandwich/Kroll combos too.

Klaus

[/ QUOTE ]

Thanks for the compliment. Much appreciated.

As for using this with other lights, there is a possible "gotcha". This problem arises if the boost circuitry sees the lower voltage and tries to increase the current to make up for it. This will overload the resistor, causing it to let the magic smoke out. This should only be a problem when using low value resistors (under 6 ohms at a guess) or multiple batteries. 3 x CR123A is 9 volts, so a 5 ohm resistor may not drop the voltage enough to force the light out of regulation.

If you smoke the resistor, you will end up with only the "full power" mode left.

On a related note. I see a 66 ohm resistor drops the current in my new streamlight TL-3LED to 45 ma. Total power disipated by the resistor just is just inder 1/8 watt. The LUX5 at 45ma still has a killer hot spot that's plainly visible on the far wall of my living room with the lights on.

Daniel

Re: simple high/low drop-in for Arc LS / L4

Hi Folks,

I changed the design a bit so that it uses only one spring and does not have to be soldered after the epoxy is applied. If anyone wants the gory details I can post them. The end result is functionally the same, the new way is just a bit easier (for me, anyway) to assemble. Being a good techie, I'm never quite satisfied. /ubbthreads/images/graemlins/smile.gif

I also posted in the B/S/T forum that I'll sell completed units for $12.50 each including postage. Ordering information is there in a thread titled "FS: Hi/Low beam spring for ARC LSH".

I've gotten several queries from folks that want to use one in a modified LS. Those would be the ones hopped up to drive the LED at 700 ma. The mod works fine with those witha 10 ohm resistor.. It will also work with other lights with 3 volt power packs.

I've been sick this last week, so I've been slow to repsond to folks. Sorry about that. Let me know if I've forgotten to respond to an of you.

Daniel

Re: simple high/low drop-in for Arc LS / L4

Thanks again Daniel,

and yes - please tell us the "easier way" /ubbthreads/images/graemlins/grin.gif


/ubbthreads/images/graemlins/thumbsup.gif

Klaus

Re: simple high/low drop-in for Arc LS / L4

Will this drop in work with first run LS's, with voltage regulator. Current ARC LS's have current regulation, but you knew that.

Bill

Re: simple high/low drop-in for Arc LS / L4

Actually, I did not know that the original had voltage reg VS the current model's current regulation.

I saw it work in an LSH with the serial nuber "002" last Friday, but that does not answer the question.

The mod allows you to knock the LS out of regulation. Does the first run LS drop into moon mode when the battery voltage drops? I'd appreciate it if you could test it for me. Simply use a 10 ohm resistor to complete the circuit from the negative end of the battery to the threads of the ARC's body. The 10 ohm resistors are available at radio shack in a pack of 5 for one dollar.

Daniel.

Re: simple high/low drop-in for Arc LS / L4

I will get some at RS tomorrow and test. Can I test for current draw at same time?

Bill

Re: simple high/low drop-in for Arc LS / L4

[ QUOTE ]
Bullzeyebill said:
I will get some at RS tomorrow and test. Can I test for current draw at same time?

Bill

[/ QUOTE ]

Sure. Just set your meter to milliamps and go from battery to resistor to meter to threads. It sometimes takes 4 hands to do that. I frequently tape the light to a solid surface like the coffee table, much to my wife's chagrin.

Daniel

Re: simple high/low drop-in for Arc LS / L4

Hi Folks,

I'm going to try to describe the new version and the technique used to build it.

General:
A single spring is insulated from a brass washer. A resistor is connected from the washer to the spring, as low as possible. The resistor is bent in such a way that as the spring is compressed the lowest loop contacts the resistor's lead, giving full power.

There are several key points;
<ul type="square">[*] Soldering should be done before applying epoxy. Heat weakens epoxy.
[*] The resistor's leads should not have to move. If they do, they will eventually break.
[*] The lowest coil should be coated with epoxy to prevent the contact from shorting.
[*] A 1/4 watt resistor can be made to fit. These are easier to find than 1/8 watt.
[*] The epoxy sets quickly, so only epoxy 3 or 4 at a time. I find that I make 3 batches of epoxy with each run. One to paste the spacers, one to attach the spring and a final to make sure the bottom coil and resistor are properly coated.
[/list]

PARTS LIST:
Spring - 3/8 x 3/4 x .032 (C-566 from century springs). Use one half
Resistor - 10 ohms for an LSH-P
Washer - Brass #6 from True Value. 3/8th inch outside diameter.
Spacer - Cardboard or plastic disc cut to match washer.

Here's the spacer, the resistor soldered to the washer and the spring.


Supplies:
JB-Weld - Kwik or Marine.
Solder - 40/60 rosin core


Tools:
Low wattage soldering iron with small tip
Needle nose pliers
Fine sand paper (200 grit or finer)
Small file or dremel with grinder.
Exacto knife or scalpel.
Any ohm-meter (DMM, analog, etc).

Pictures:
In these drawings, the gold is the brass washer. The light grey is the plastic spacer. The dark grey are the leads. The spring is blue and the brown is the resistor.

This is a drawing of the device from above. Note the lead of the resistor that goes all the way to the edge and then folds back on itself before connecting to the washer. The spacer is not shown for clarity.



This next drawing is a cutaway from the side. It gives an idea of the layers involved.



Next we have the side view.



Ok, here's the project without the final epoxy coat. The spacer is epoxied to the washer. In the second you can see the edge of the resistor's lead pushed out of the way so that it doesn't get epoxy on it in the next step.




And lastly, the finished product. In the second picture the contact is clearly visible.


Adjustments:
Like the type 1 spring assembly, the springs should be short enough that no extra pressure is placed on the battery when fully compressed. There are enough variations in the battery pack, battery size and kroll switch that no single spring length will be perfect. Follow the spring length instructions from the type 1 instructions.

After the spring is short enough, you can adjust the contact point by bending the top coil of the spring down or up. Use two pairs of pliers to avoid over stressing the epoxy. Bend the last coil towards the washer to delay the full beam. Bend it up (away from the washer) to cause the full beam when the battery pack is only half screwed in.

No, I am not selling these.

Daniel

Re: simple high/low drop-in for Arc LS / L4

Wow. I really liked the original idea, liked it even better when the kroll version came up, and am now in awe of this option. Great Work!

Re: simple high/low drop-in for Arc LS / L4

[ QUOTE ]
Bullzeyebill said:
Will this drop in work with first run LS's, with voltage regulator. Current ARC LS's have current regulation, but you knew that.

Bill

[/ QUOTE ]

Bill,

just tested this for you - and YES it does work - you will obviously need to use one of the TSP 123 or TSP 2AA bodies with the old rev1 head though - and you MIGHT need to fiddle a little with the length of the springs.

I can confirm that the low beam does work while its brighter than the current regulated rev2 falling in moon mode as the resistor seems to drop the voltage not enough to get a similar dimm brightness level. Remember the rev1 circuit worked to lower voltage levels than the rev2 which might be part of the issue.

It might be advisable to use a slightly higher resistance for this rev1 ARC mod though - for modding the original twistie packs there is still Daniels original moon-washer approach which is described at the beginning of the thread.

Klaus

Edited for clarity

Re: simple high/low drop-in for Arc LS / L4

Klaus, I'm having problems parsing this: [ QUOTE ]

he low beam does work while being slightly brighter than the current regulated rev2 falling in moon mode as the resistor does drop the voltage to the rev1 head to a lower and therefore not as bright level.

[/ QUOTE ]

Was the revision 1 dimmer with 10 ohms, or was it brighter? Is it likely that the difference is simply one of the BIN of the Luxeon?

Daniel

Re: simple high/low drop-in for Arc LS / L4

Daniel,

excuse my poor english and spagetti-type sentences /ubbthreads/images/graemlins/blush.gif

What I wanted to say is that the low level with the rev1 circuit (voltage regulated) is BRIGHTER than the rev2 circuit (current regulated) using the same switch (yours) at 10Ohm I think.

I *think* this is due to the rev2 circuit falling out of regulation with the 10Ohm resistor whereas the voltage regulated rev1 circuit which works down to lower voltages anyway keeps the current to the LED higher when resistored down by 10Ohm. Therefore my *guess* that using a slightly higher resistance might drop the rev1 circuit to the same lower brightness level.

As the combination of TSP packs with Rev1 heads was never shipped by ARC and might not in too broad circulation though this shouldn´t be an issue as its working OK, just a bit brighter - if you want to be able to offer the "right" brightness with the old rev1 heads & TSP combos too I could do some further testing and see what resistor value would be appropiate to reach a somewhat similar (lower) brightness level.

Klaus

Re: simple high/low drop-in for Arc LS / L4

Just to let you all know that Gadget_Lover is an ingenious person! I just picked-up one of his drop in high/low units and it works perfectly!

Low Power similar to what an AAA-LE would put out and the original Hi Power the ARC LS normally puts out! Well worth the cost to purchase from Gadget_Lover.

Thanks, Daniel!

Re: simple high/low drop-in for Arc LS / L4

Dlent, It was nice to meet you. Thanks for the testimonial. /ubbthreads/images/graemlins/smile.gif

Klaus; Your engish is MUCH better than My german. It's also better than many people who post messages on the internet. I only know the german word for no, and I'd probably misspell it. /ubbthreads/images/graemlins/smile.gif

The exact level of brightness varies from light to light, so I won't worry about it unless someone makes a special request.

Daniel

Re: simple high/low drop-in for Arc LS / L4

Congratulations to gadget_lover for an elegant, ingenious design. I'll probably order a couple.

One concern though: is it possible that this mod might make the Kroll less reliable? I'm thinking of jamming, broken springs, etc. I know the Krolls aren't perfect to begin with and I wouldn't want to increase the odds of a malfunction.

Re: simple high/low drop-in for Arc LS / L4

I don't think it makes the switch less reliable in the other ways it fails (that's usually inside the mechanical portion of the switch). I think that it shouldn't increase the odds too much, especially this new design.

Re: simple high/low drop-in for Arc LS / L4

I'll probably draw fire for this, but I'd assert that the kroll may become more reliable.

A prime cause of switch failure is burn spots on the contacts where the initial contact is made. My understanding is the burn is worse with more current.

The tendancy is to leave the LS is low beam most of the time so most of the time when you turn it on there's only 30 milliamps or so instead of up to an amp.

Having said that... I could be wrong! /ubbthreads/images/graemlins/smile.gif

If properly adjusted, the spring will not add any stress to the kroll or the battery. Only the spring flexes, so there should be nothing extra wearing out.

Daniel