120vRMS AC to 5v2mA DC
Warning! Any voltage above 30 is considered unsafe. While the circuits presented here work and are safe, they are not guaranteed to be. Exercise your own caution when using these designs as I will not be held liable for any injury.
Nothing at all fancy about this circuit. Super simple way to get a lower power source from the line power. Good for a low power control circuit or some kind of data aquisition system. The zener is required to prevent the voltage on the capacitor from eventually exceeding the abilities of the regulator. This is only a concern if the load is not drawing enough energy to keep the voltage low enough that is. The zener can be ommitted if the circuit is constantly drawing sufficient energy. If your regulator has an enable/disable pin, you may want to add a voltage divider to ensure it only comes on when there is sufficient power.