handcannon2

I understand the purpose of the diode but I do not understand the placement in the circuit. I guess the use of the three pots in the circuit is to get more adjustment on the voltage? Should the diode go between r4 and ground?

I put this together outside of the car to test and I am using a 12 volt dc supply that I put together from a old computer power supply. It shows to be putting out 12 volts total. The pots I have came from Radio Shack and are marked 5k-ohm 500vdc .5 watts.

OK I,m game. If it won't work this way does anyone know how to fix this or how about one that will work. Also if this one does not work why publish it? I guess I'm missing the point unless someone has stock in a parts co. Just kidding.

I put the circuit together to dim my headlights but everytime I hook power to the board one of the pots smokes. This is the first time I have tryed to put something like this together and I am not sure where to look for problems. I have checked the wiring out several times and it looks right. Any comments would be helpful. Thanks