555 Switch Mode Power Supply

the cap isn't charging at all, there's not enough power coming through

Problem is, your regulator is running at a few khz, but the simspeed is set for the 60hz ac source. So place a dummy source sone 10khz. Disadvatage is your transformer supply will take to long and has to be replaced by a fixed voltage. I think the goal is the 555 regulator and not this stupid transformer and rectifier, right? Keep it up!

The cap isnt grounded thats why, try grounding the bottom of the 5.6v zener, works perfectly then. Nice circuit :-)

Sorry hurz but your totally wrong, as i said ground the bottom of the 5.6v zener and it works perfectly.

Sorry mikey, what i said is still valid. You failed, its very magic how you tested this circuit with heavy undersampling!

Worked for me when I did as Mikey said

Its doing someting spiky but not what it suppose to do in real. You need at least a simspeed of 10us/s which is blocked by the 60Hz source. I would remove ot and place a dc 10V and than tune the simspeed as needed. If you do so we can take a closer look what else is not correct. E.g. the ground, the nmos is a bit to weak, etc....

You should cut your tung out and ask God for it back the next time you question hurz!!!

Thanks hurz and mikey, you were both right. I missed that ground, and eliminating the 60Hz portion of the circuit worked wonders. I'll update this one in a bit. One more question for you guys, if you don't mind - it's been a while since my electronics class. I've noticed that most spec sheets for transistors do not include the types of values EveryCircuit uses to define them. Instead of channel width etc. the spec sheets show things like resistance while fully on, etc. How do you pick appropriate values? I find that this circuit won't handle a heavy load (try 50 Ohm instead of the 1k, which is closer to what I need to drive when I build this circuit) unless the transistor has its values modified, but I don't know what's reasonable for these transistor values in the real world since they aren't in the spec sheets. Thoughts?