MOSFET power supply?

[iipreca]

Hi folks, I have a question about FETs. How pure does the DC power feeding a fet have to be? I have the circuit attached and when I powered it up, it vaporized R6 a 56 ohm 1/4 watt. The only thing that I can see happening is the FET is shorting, and the only thing I can point to is I don't have it filtered enough? what is the max ripple a FET can handle? My R Load in my test run was a 60 watt incandescent light bulb.

Thanks
iipreca

 

[duke37]

You have the fet 'upside-down' so that you have blown the gate with a couple of hundred volts on it.
The 555 may have suffered also, test this before replacing other components

Gate maximum voltage +/- 30V

 

[duke37]

C1 will do nothing when the load is turned on, it cannot provide such a high current, it may well go pop.
Is the 7812 necesary, a 12V zener and large electrolytic capacitor would probably do the job.
There should be capacitors on the input and output of the 7812 to ensure stability.

 

[GonzoEngineer]

I am surprised you didn't blow everything on that schematic!

No offense meant, but please run your next schematic by us on this forum, before you electrocute yourself!

 

[iipreca]

No, I have the schematic drawn wrong, sorry about that. I have it wired correctly.

iipreca

 

[duke37]

Show us the actual circuit that you used.
Did the 7812 have no more than 30V input?
Does the 555 still work?
If you blew R6 then perhaps the ground was missing.