Well, I am making a small circuit which looks like this:
When simulated, the load current gets up to about 200-280 mA no problem, so I want to implement this circuit in real life. My only problem is, I want to use either an oscillator, a microcontroller or a 555 timer as the source of the PWM signal V1, but such a device can only source about 20mA, so I am wondering, where does the current through the load come from? The constant 3V source V2? Or does it also come from V1? And if V1 also sources current, how much does it source? Is it under 20mA?