how can I economically convert 120vac to 12vdc to power a low amp draw transmitter/receiver
Short of buying and cannibalizing wall warts from ebay, I would like to build a handful of reliable and safe transformers/adapters or whatever would be the correct lingo. I have a little bit of experience with circuitry, diagrams, voltage drop, etc.. but choosing the right parts off the net is the difficult part. I have also found diagrams for "transformerless" power supplies.. https://www.ebay.com/itm/12V-4CH-Channel-Wireless-Remote-Control-Radio-Relay-Switch-Transceiver-Receiver/122036934849?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649
this is a link to the transmitter/receiver combo that I am interested in. According to the specs, it only draws 13mAh.
Any input, or links to other projects would be appreciated..