yesterday i bumped my head on a project where i need to run a lappy in my car, and didn't want to use an UPS or any commercial 12 to 'kill your self when its humid voltages'.
So ive constructed a simple step up, works ...
The coil is singing / crackeling making a screaming cricket noise under light loads. The noise is gone when under a heavy load.
Its unbeareable, what should i do with the coil or circuit to make it stop screaming?
Everything was DIY in this project except for the pwm MC34063 chip.
Ive used an IRFZ44N as transistor with a class B driver to drive the 1nF fat gate .. gate driving edges are very sharp and thight!