1 Channel 12v Relay Module

£ 2.70


Here we have a 1 channel 12v relay thats perfect for safely controlling high current sources.

This unit can function as both a Low level trigger or High level trigger by using the jumper.

  • Maximum load: AC 250V/10A, DC 30V/10A
  • SMD optocoupler isolation
  • stable performance
  • trigger current 5mA
  • Operating voltage 12V
  • high or low trigger by a jumper setting
  • fault-tolerant design. Even if the control line is broken, the relay will not operate
  • Power indicator LED(green)
  • status indicator LED (red)
  • module size: 50mm*26mm*18.5mm (L*W*H)
  • DC+: positive power supply (VCC)
  • DC-: negative power supply (GND)
  • IN: can be high or low level to control relay
  • NO: normally open relay interface
  • COM: Common Interface Relays
  • NC: normally closed relay interface

1 Channel 12v Relay Module

How Relay Contacts Work:


Relay output

Notice the 3 screw-type terminals. They are labelled "NO", "COM", "NC". Those labels mean:

  • NO: Normally Open
  • COM: Common Connection
  • NC: Normally Closed


Relay internals

This shows the switch that is inside the relay. This switch is "thrown" by the electromagnet inside. The diagram shows that COM is connected to the Normally Closed contact. That's the case when the relay is off. When the relay is turned on the electromagnet flips the switch up and COM is then connected to Normally Open. So, if we want a lamp to be on when the relay is on, we connect our circuit from COM to NO.


Relay input

Here you would connect VCC and Ground and the signal would be how you intend to switch the relay. If your relay is High level controlled then you would need to pass in a high current and if your relay is Low level controlled then switching would occur when a low current is passed in.

Some relays allow for low or high level switching based on a jumper, as shown in the image.