Parts used we're a standard 555 & IRF620N MOSFET & 12 blower from a Chevy Tahoe.
I needed this for my power supply fan motor.
I'm using a 12 volt blower from a car which pulls 6-9 amps.
This is to cool the heat sink with 12 - 2n3055, this is a small sink with lot's of ducted air flow.
I am using two 3055 as base power driver and have two set's of 5 =10 matching transistors for the 100 amp output.
Each 2n3055 is rated @15amps, so 10=150 amps max.
Using the transistors at 10 max limited the heat and stress on the part's extend life of power supply.
By using a car blower the life of the fan is about 10 years before a replacement is required.
Yes everything is over built but I hope to not ever work on the project again.
Outside of cleaning the dust from the blower and ducting.