I want to build a small single-piece enclosed device that takes power directly from a standard 120VAC outlet and switch on/off 120VAC external devices. I need less than 50mA to power the microcontroller and circuitry. I intend to produce appx 20 device/month. Wall transformers are a poor option because of the single-piece packaging requirement.

I have seen several possibilities for power supplies in small embedded projects, but I would like to hear opinions about a "good" power supply. I qualify "good" as meaning simple (cheap and easy), reliable, safe, and efficient -- no significant heat produced. If I could solder a $10 250mA "wall transformer" type power supply onto the PCB, I would do it in a heartbeat, but I haven't seen such an OEM-packaged wall transformer.

bbaker

Here is a circuit I use that should provide about the right amperage without the need for a large transformer:

Here is another circuit that you might be able to adapt.

NOTE: Two LEDs are wired back-to-back.