technogeek
New Member
I need to power a DC fan off of rectified 120VAC (169V DC). I found one that takes 12V/0.4A.
Here is what I was thinking of doing... If I take a PWM signal and throw it into a smoothing capacitor, I'll have a nice linear DC signal. So, say I take a CMOS 555, something that draws low current. Have a linear regulator to take the 169V down to 12 volts to power the 555. Have the 555 switching a mosfet with the drain on the Vcc, source going to a reverse biased diode (prevent flyback) and the load and a smoothing capacitor.
In theory ( ) if I adjust the duty cycle to say 10%, I should be able to get a 16V DC output (with a fair amount of ripple)
It's kind of like a switching regulator, but no coils. Will it work?
Here is what I was thinking of doing... If I take a PWM signal and throw it into a smoothing capacitor, I'll have a nice linear DC signal. So, say I take a CMOS 555, something that draws low current. Have a linear regulator to take the 169V down to 12 volts to power the 555. Have the 555 switching a mosfet with the drain on the Vcc, source going to a reverse biased diode (prevent flyback) and the load and a smoothing capacitor.
In theory ( ) if I adjust the duty cycle to say 10%, I should be able to get a 16V DC output (with a fair amount of ripple)
It's kind of like a switching regulator, but no coils. Will it work?