Recently I made a timer. The circuit is shown in the figure. The power supply uses a resistance-capacitance step-down, 24V relay drive current is 15mA, stc15W101 single-chip microcomputer, and the normal working current is 5-6mA. Now the power supply part CBB heats up, and the electrolysis C3 also heats up. Please high Workers give pointers.
Aaron Posté sur July 20, 2020
In this era, there is no need to step down. For safety, the voltage isolated from the AC is all over the ground, and it is safe. It is recommended.
Lily Posté sur July 20, 2020
It should be that the output current is too small.
Austin Posté sur July 20, 2020
It stands to reason that the CBB should not be hot. You can try another 400V safety capacitor. C3 look at a higher withstand voltage.
