I picked up a few of these relay modules at my local electronics shop with out any documentation which is par for the course. So here is my swing at it.
KY-019 Relay Module is used to control AC circuits, the relay acts as a switch that responds to a signal received from an embedded controller, it has an integrated LED that indicates if the signal is high or low. This device is commonly used in IoT projects to control a 120vac load.
The KY-019 consist of a 1Mohm resistor, a LED, a 1N4007 rectifier diode and a 5VDC relay capable of handling loads up to 250VAC and 10A.
|TTL Control Signal||5VDC to 12VDC (some boards may work with 3.3).|
|Maximum AC||10A 250VAC|
|Maximum DC||10A 30VDC|
|Contact Type||NC and NO|
|Dimensions||27mm x 34mm [1.063in x 1.338in]|
- Neutral - Never switched your return. (like the ground side of your logic)
- Hot - Just that this is what goes to your circuit breaker.
So you Neutral line (wire) goes from the source to the device.
and the hotline goes to the Common Screw on the Relay Board
and the device you are going to control connects to the NO Screw on the Relay Board. In this way when your relay is energized
your device will be on. Just a note if you had used the NC Screw then the device would be 'ON' when your relay was not energized.
Please DO NOT use this to control something in your house. This device is NOT UL rated and can never be wired to a US 15amp outlet! Always be very careful when experimenting with AC, electrical shock can result in serious injuries or death.