Quote:
Originally Posted by Coach Seb
I bought the exact same thing that was recommended by apm4242....
- LED Flashlight with zoom
- DC-DC Voltage Converter/Regulator
- Spike Relay
I'll check the voltage again... last night we had 10V on the spike relay, i did not check the voltage after the converter yet as we assumed we fried the spike... but yet between test it worked... still wondering...
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I tried sizing a resistor that would work for the Hausbell LED Flashlight but could not find the LED data sheet. I don't have the flashlight in front of me, so I couldn't try to pull a model number off of the LED. Going off of what CREE offers, I tried to find an LED using the flashlight specs (300lm, size, Q5, etc) and found a few LEDs with a forward voltages of between 2.9 V and 3.5 V and forward currents of 1000 mA for white light.
Using the equation R = (Vs - Vf)/i where Vs is supply voltage (3.3 V in my case), Vf is forward voltage, and i is current, gave resistor values between 0.4 Ohm and 0 Ohm. From what I have read and from how the math works out, you don't need a resistor if the supply voltage is less than the forward voltage and there are no voltage spikes (assuming the LED lights up at all).
I'm a little out of my wheelhouse with this stuff. Hopefully someone with a little more experience will come along and offer some wisdom...
Cree Components
Similar LED Data Sheet 1
Similar LED Data Sheet 2
LED Current Limiting Resistors Tutorial