Recent content by ctom
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Help me troubleshoot another circuit?
Ok, now I'm both confused and curious... In the orignial schematic, the output of the 555 time goes high and begins to charge the capacitor C2 through R1. As the voltage across C2 rises and goes above 2/3 VCC, the timer will discharge the capacitor via the discharge pin. Once the output goes...- ctom
- Post #16
- Forum: Flashlight Electronics - Batteries Included
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Help me troubleshoot another circuit?
I haven't studied the circuit in detail but I think one leg of resistor R1 (the one that is connected to the output of the 555 timer) should be connected to +12 VDC (or +11 VDC in your case) instead of pin 3 of the 555.- ctom
- Post #10
- Forum: Flashlight Electronics - Batteries Included
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The Dangers of Working with a High Voltage Supply
D-Dog, First, I'm glad to hear your injuries were relatively minor - you are one lucky dog! Secondly, I'm dismayed the scenario that I described in my second post came to pass... I suppose it's all academic now since you are no longer using the power supply but just to close the loop on the...- ctom
- Post #25
- Forum: Smoke and Fire, Hot Cells and Close Calls
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The Dangers of Working with a High Voltage Supply
Re: Constant Voltage vs Constant Current vs Constant Power Again, without the specifications available (or the circuit schematic), it's hard to predict the output. As an experiment, you could connect an ammeter in series with the battery and power supply. If the supply is outputting 0.167...- ctom
- Post #4
- Forum: Smoke and Fire, Hot Cells and Close Calls
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The Dangers of Working with a High Voltage Supply
Re: Constant Voltage vs Constant Current vs Constant Power A constant power power supply will vary the output voltage and current to maintain a constant power level to the load (power = voltage*current) while a constant current supply will only vary the output voltage in an attempt to maintain...- ctom
- Post #2
- Forum: Smoke and Fire, Hot Cells and Close Calls
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6 amp LED Driver Project
Re: Hobby voltage regulator Since you are in the Bay Area, there are a lot of fab houses locally. I've used PCBFabExpress (www.pcbfabexpress.com) with good results as well as Sierra Proto Express (www.protoexpress.com). Both vendors are located in Sunnyvale and require Gerber files from...- ctom
- Post #21
- Forum: Flashlight Electronics - Batteries Included
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6 amp LED Driver Project
Re: Hobby voltage regulator I just checked Digikey's website and they do have them in stock: http://search.digikey.com/scripts/DkSearch/dksus.dll?Cat=2556570&keywords=LM22679- ctom
- Post #16
- Forum: Flashlight Electronics - Batteries Included
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Mosfet as a diode , i donno is that gonna work?
Another option is to use a low saturation bipolar transistor like the Zetex ZTX851 in place of a MOSFET. It has a Vce(sat) of 50 mV typical (100 mV max) at 1 amp. One potential downside is that the base current drive is 50 mA.- ctom
- Post #9
- Forum: Flashlight Electronics - Batteries Included
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Mosfet as a diode , i donno is that gonna work?
yes, the diode is part of the MOSFET - I should have been more concise. I tend to agree that simplicity is better and your original idea of using a low forward voltage drop schottky diode is the way to go...- ctom
- Post #7
- Forum: Flashlight Electronics - Batteries Included
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Mosfet as a diode , i donno is that gonna work?
Probably not because most MOSFETs have a parasitic diode connected across the drain and source so that when the solar cell voltage falls below the battery voltage (less the diode's forward voltage drop - typically 1.3 volts), the battery will begin to discharge into the solar cell through the...- ctom
- Post #4
- Forum: Flashlight Electronics - Batteries Included
