DIYbanter - View Single Post - A wall-wart alternative

wrote:
I finally got tired of replacing the 2 C-cells in a clock with a moving
pendulum, so I measured the current (3 volts at 340 microamps) and built
a charge pump

We used to use a similar circuit for powering electronic thermostats
when I worked for Potterton Boilers here in Blighty. We used just one
Class X capacitor feeding a 24V zener and smoothing capacitor.

I also used to use one for charging the NiCads in my caving lamp. Of
course I made the classic mistake of plugging it in then picking up the
crocodile clips to connect onto the battery (rather than connecting
onto the battery then plugging in). Rectified 240V doesn't half hurt.

--
Malc