On 1/6/22 6:04 PM, Matt Burke via cctalk wrote:
Quiet regulator: http://www.9track.net/posts/h744/h744_ba11_q2e.png
Noisy regulator: http://www.9track.net/posts/h744/h744_ts11_q2e.png
The yellow trace is the emitter of Q2 (input of L1) and the cyan trace
is the output of L1. Q2 seems to be switching partly on then fully on in
the noisy regulator. it should of course be fully on or fully off as
seen on the quiet regulator. Also the switching frequency seems to be lower.
Yes, the 2nd unit is running at 5 KHz, clearly explaining
the noise. Possibly there is a bad flyback diode, or
something causing the different waveform.
Jon
