rrmuttFeb 15
Oh hey another janky AC-DC converter like the one spotted in @mossmann ‘s shredder. How does it work? 1/3
Show threadrrmuttFeb 15
You will notice no transformers. That's a 300Ω resistor and the big brown cap is 560nF. That makes a highpass. It's not the L-topology RC filters you may have studied -- the R is not to ground, it's in series. 2/3
Show threadrrmuttFeb 15
The highpass filters the AC and reduces the amplitude by 20dB -- a factor of 10. So 120VAC in becomes 12VAC out. This goes to the classic bridge rectifier and smoothing cap for roughly 12VDC out. 3/3
Show threadMichael Ossmann
@rrmutt My eyes are cringing from the 60 Hz flicker from here.
Feb 16 at 12:15amMastodon for iOS
Show threadMichael OssmannFeb 16
@rrmutt well, 120 Hz actually
Show threadrrmuttFeb 16
@mossmann To be fair it does have a filter cap, unlike the horrid holiday light strings...