I'm very much a beginner at creating my own circuits and using an Arduino so please excuse any stupid mistakes and oversights.
What I want to do is light a very high power LED for 1/2 second or so using a capacitor, a boost converter (from 5v to 20v), and the innards of a power bank. I want to use two solid state relays in the circuit. The first one will close and allow the capacitor to charge and then when the capacitor has full charge the Arduino will close the second one and cause the light to flash brightly for a split second. After reading a few articles about powering LEDs from a capacitor it seems I need a resistor in the circuit but I'm not sure what size.
Also, I'm using these two online calculators to get an approximate time that the LED would stay lit for:
- I'm giving the first one the values of 20 volts and 33,000 uF
- On the second if I enter 6.6J and 0.5 seconds I end up with 13.2 watts. My LED draws 750ma at 17v so 0.750 x 17 = 12.75 watts
Am I right in thinking then that the 33,000 uF cap should power the LED for 1/2 second when fully charged?