So I was playing with a simple boost converter yesterday, which puts out AF noise. The link is below but it uses an MC34063, external FET, and a 100 uH coil.
https://threeneurons.wordpress.com/nixie-power-supply/hv-supply-kit/
When I scoped the output through a high frequency filter, I saw a low frequency sawtooth output. Audio filtering reduced its amplitude but not enough for me to wonder why. Photo one below...
I scoped the output of the controller itself and found that it's not putting out a steady stream of pulses. It's giving me bursts of 60 KHz pulses at less than 700 Hz.
Other than the high audio ripple, I was able to get it to deliver 5w at 120v. I'm trying to make it clean enough to power an audio amplifier using some 12V car radio tubes. It put 120v into a series pair of 1500 ohm resistors which was nice.
Can someone help me figure out why this is happening? Maybe I can salvage this thing. It would do fine for Nixie tubes but I don't use those.
Ed
https://threeneurons.wordpress.com/nixie-power-supply/hv-supply-kit/
When I scoped the output through a high frequency filter, I saw a low frequency sawtooth output. Audio filtering reduced its amplitude but not enough for me to wonder why. Photo one below...
I scoped the output of the controller itself and found that it's not putting out a steady stream of pulses. It's giving me bursts of 60 KHz pulses at less than 700 Hz.
Other than the high audio ripple, I was able to get it to deliver 5w at 120v. I'm trying to make it clean enough to power an audio amplifier using some 12V car radio tubes. It put 120v into a series pair of 1500 ohm resistors which was nice.
Can someone help me figure out why this is happening? Maybe I can salvage this thing. It would do fine for Nixie tubes but I don't use those.
Ed