Rc > 100Rs allows control of current of Iout with only milliamps of Ic. Figure 3 shows the idea fleshed out into a complete PWM-controlled 18 V, 1 A grounded-load negative current source. Figure 3 An ...

In [Rouslan]’s circuit, the audio signal is passed into the analog input of an ATtiny45. Inside this microcontroller, these analog values are sent to the MOSFETs through a PWM output.

You learn tons about everything from circuit concepts and assembly skills ... so whipped up a neat design using analog meters to display the time. The build relies on that old stalwart, the ...