5V relay module
Microcontroller development board can be used as modules, can be used as appliance control.
5V-12V control signal of the TTL.
Control DC or AC signals can control the 220V AC load.
There is a normally open and one normally closed contact
Power LED
Controlled light, pull off, off off
Increased transistor drive a relay coil, the control pin high impedance.
Control pins have pull-down circuit, to prevent floating relay malfunction