More complex than expected
Added 2024-01-07 03:11:53 +0000 UTCI thought I'd take one of these apart, thinking the circuitry was going to be very minimalist. I thought it might be a chip, transistor and protection diode, but it really goes to town on noise suppression and overload protection.
Comments
it looks like a over sized Everlasting Gobstopper from Willy Wonka. LOL
Jonathan Hughes
2024-01-08 04:25:44 +0000 UTCThe 0R68 in the source provides a bit of current feedback at startup by eating into Vgs, but at the expense of running the FET less like a switch and more like a dimmer. That's why it needed extra heatsinking. I can less understand the PTC in series though. It's something you want to trip decisively. I don't know how it would behave in this kind of scenario, and it's not easy to model because of the thermal aspect.
Mike Page
2024-01-07 19:43:40 +0000 UTC
