I recently took apart a crock-pot cooker that stopped working correctly.
It had two boards:
- One that dealt with the high-voltage for controlling output to the heating element
- The other had a 4-bit microcontroller and a few buttons/LEDs.
I was surprised to see no transformer anywhere, and very few parts, considering there was a signal labeled
+5V for powering the microcontroller.
I reverse-engineered the schematic:
Is it me or is this a really crappy design?
I was very surprised to see that the DC
GND was connected directly to the 120VAC
Is the 5V DC basically just a rectifier with a voltage divider?