Smart Wireless Doorbell 45 Songs Polyphonic Ringtones & 200m Transmission
A part of the review has been auto-translated.
Dear bang good team,my doorbell not working can you tell me how to use it
Easy setup, pleasant ringtones, shows ambient temperature when plugged in. Good value for wireless doorbell with two receivers.
US plug version contains a capacitive dropper circuit appropriate for 240v, not 120v. This results in low voltage to the receiver/speaker/LEDs etc. which run on 5v DC (if my math is right, the dropper circuit is designed to produce 4.9v DC). Symptom is that when receiver is plugged in, only a very faint ". C" appears on the LED display and nothing else works. You could fix this by plugging the receiver into a cheap voltage doubling 120v-240v adapter. I opted to remove the AC side of the circuit and solder a USB plug to the low voltage + and - points where the daughterboard is connected (circled in the photo I uploaded), since transformerless dropper circuits like this provide no mains isolation and should never be used in plug-in products designed to be touched like this one. The receiver only draws about 1W and will run fine from even the smallest USB AC adapter. Would love to see an OEM USB version of the receiver, because the product works great once properly powered.