/diy/ - Do It Yourself

>>1582029
I've added the zener back. I also changed the transistor from shitty signal (beta 80m) to decent power (beta 10, very conservative). After changing the transistor beta, it seems that the voltage overshoots if I step up the duty cycle too fast. Also, I tried changing the output cap to bigger values (up to 100mF), but it still overshot and I don't want to damage my fan.
Another problem with quick step up in duty cycle is the current from the source shoots way the fuck up (up to ~8A) and the zener triggers dissipating huge amount of energy (90W for ~1ms), see pic related.
In reality, my power supply is only able to supply ~3A and there's a bunch of other stuff connected to it. Will this damage my power supply? Will stepping up quickly fry the zener diode? Or are these spikes only visible in simulation due to idealized components (0Ohm inductor, etc.)?