LED striplight driver test
Using a 555 timer to generate a PWM signal using the circuit described here: http://www.reuk.co.uk/LED-Dimmer-Circuit.htm to drive an NPN-PNP pair which then drives an N channel IRF630, dimming the lights accordingly. The entire system is running from a 12v computer power supply. The capacitors on the rails are for smoothing the DC, the power supply would buzz angrily without them. Now it whispers, disgruntled. Unfortunately my ammeter is not working properly or I would give more information about power draw. In the final design I'll use smaller BJT transistors as the ones I used were simply laying on my desk, and I'll have a heatsink on the MOSFET. After ten minutes of running both strings of lights it gets a little too warm for comfort.
Using a 555 timer to generate a PWM signal using the circuit described here: http://www.reuk.co.uk/LED-Dimmer-Circuit.htm to drive an NPN-PNP pair which then drives an N channel IRF630, dimming the lights accordingly. The entire system is running from a 12v computer power supply. The capacitors on the rails are for smoothing the DC, the power supply would buzz angrily without them. Now it whispers, disgruntled. Unfortunately my ammeter is not working properly or I would give more information about power draw. In the final design I'll use smaller BJT transistors as the ones I used were simply laying on my desk, and I'll have a heatsink on the MOSFET. After ten minutes of running both strings of lights it gets a little too warm for comfort.