Here is a random travel charger for the Nokia 8210 mobile phone. The casing is marked with the input AC220V/50Hz ( Figure Nokia mobile phone charger circuit The author made this charger to analyze, draw a circuit diagram for the reader to use and repair reference, the op amp IC in the circuit is used as a comparator. The handheld addresser is used to program the address of the monitoring module offline. When in use, connect the two output wires of the handheld encoder to the communication bus terminal (terminal label 1, 2) of the monitoring module, turn on the black power switch on the right side upwards, and press "ten Add", [Subtract ten", [Add one place" and [Subtract one place" to program the address. Hd Encoders,Twitch Encoder,Resolver Encoder,Incremental Rotary Encoders Changchun Guangxing Sensing Technology Co.LTD , https://www.gx-encoder.com