I just got a board from a dead de-humidifier, which was powered straight
from 220VAC. What at first looked like a custom DIP18 chip certainly
seems to be a PIC judging by the pinout. No transformer for power input.
No 7805. No nothing. The regulation consisted of a big 1uF unpolarised
cap, some (smallish) inductors, a large resistor, diodes, and a couple
Zener diodes (which I assume did the "regulation"). Is this
reliable/safe? Certainly the most simplistic regulation circuit I've
ever seen (+5V was tied almost straight to Neutral!). Wonder if it's
cheaper than an off-the-shelf switched 5V supply though.

Any thoughts on this? Is this actually in common use, and if so, is it
safe or reliable? Were the designers completely crazy doing this? :)
-- 
Hector Martin (hector@marcansoft.com)
Public Key: http://www.marcansoft.com/hector.asc

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