I am working on to build a dimmer for led lamp. Led driver AC input is about 220V and output of the driver is 70V under load. I placed a npn transistor (mje13007) between led ground and led driver output ground. I am driving this transistor with a PWM source.When duty cycle gets bigger, it starts to flicker. What is this problem and how to overcome?
The problem is that the driver is detecting the naive PWM mechanism as a circuit fault and is shutting down. The fix is to use a driver that supports PWM natively.