I have made a LED dimmer circuit which has 2 transistors,1 resistor and 2 potentionmeters. The brightness of the LEDs are dependent on the output voltage. Since the voltage regulator is variable, the brightness of the LEDs is also variable. The circuit is given below.
Comparing with the above circuit,the only difference is that I’ve substituted a few components & left out the 100r pot. I’m using an TIP122 ( TIP122 PDF )for the Darlington & a BD139 for the other transistor also a logic 1K pot. The circuit works fine but regards the pot it basically has no affect untill its turned half way round. Then there’s only a small bit of ajustment left between Off & On of the led.
I am wondering if there’s a way to make the pot work more evenlly. Or need I change the components?
Thanks~