Relay - Information

What is a relay

A relay is an electrically controlled switch, one might say. Through a weak control voltage, the relay is activated and can thus regulate the opening and closing of a significantly stronger current circuit.

This is best explained with an image according to point one of the installation.

Relays for vehicles come in variants for different voltages:

• 6v, as found in older cars
• 12v, which is what most cars have today
• 24v, typically used in heavier machinery

Different types of relays

• Starter Relay
  Used to provide the starter motor with the power it needs.
• Turn Signal Relay
  Used for the car's turn signals to make the lights blink by controlling the timing.
• Single Relay
  A simple relay with one characteristic, but may have multiple outputs. Also available with a fuse.
• Double Relay
  A combined relay with two different or identical characteristics. Also available with a fuse.
• Solid State Relay
  This functions like a standard relay with the difference that it has no moving internal parts. Solid state devices tend to get hot, so it is important to place them with good ventilation.

Function of Pull-in Relay

• No control voltage = circuit is open = relay is off = No current can pass
• Control voltage applied = circuit is closed = relay is on = current can pass

Function of Changeover Relay
The same as a pull-in relay but with two circuits. Circuit 1 and Circuit 2.

• Without control voltage, circuit 1 functions but not circuit 2
• With control voltage, circuit 2 functions but not circuit 1

Installation

To correctly connect a relay, start by reviewing the wiring diagram. Make sure your relay is securely mounted once the connection is made so that there is no possibility of the wiring coming loose or vibrating free, as loose connections can lead to fire hazards.

There are several different tests to check if a relay is functioning properly. Here are a couple of simple tips:

• Check the control signal.
• When checking the control signal, ensure that the two pins that are supposed to drive the load are making contact.

Accessories

• Relay Holder
  A holder for the relay. For a neat and secure installation.
• Relay Socket
  To easily connect a relay, a relay socket/connector is very convenient to use.

Problems

• Weak Control Voltage
  The control voltage is too weak, so the coil is never activated. A weak control current can also damage the relay. This can occur, for example, with low battery voltage.
• Poor Connection
  Just like all connections, a poor connection can cause problems.