Relay is one of the components included in the switch. The only difference is, this relay works automatically, namely utilizing the principle of magnetism that is exposed to electric current. Usually the relay is wrapped in a transparent cube-shaped face. And in general, relays are widely used in circuits to run motors, for TX 80 meter bands and other circuits.
Getting to Know Relay Components
Relay is a magnetic switch that has a certain resistance value and working voltage, for example a relay with a resistance of 400 ohms and a voltage of 12 volts means that the relay will be active if given a bias of 12 volts with a current of V/R = 12/400 = 3 mAh.
Relays are used to control AC voltage, the most common example we encounter is the implementation in an Automatic Street Lighting circuit.
Automatic Lighting Circuit Using LDR
The important thing to note about the Relay is the position of its legs when the Relay is working and when it is not working. Example:
Look at the picture below!
Information:
- The relay position is energized
- Relay position without electric current
To operate the relay to the position where it is energized, a switch is required to connect the electric current to the relay leg AB.
When the relay is supplied with electric current, then:
- leg number 6 is connected to leg number 13
- leg number 9 is connected to leg number 16
- leg number 12 is connected to leg number 7
- leg number 15 is connected to leg number 10
If the relay is not supplied with electric current, then:
- leg number 6 is connected to leg number 11
- leg number 9 is connected to leg number 14
- leg number 12 is connected to leg number 5
- leg number 15 is connected to leg number 8
The relay above has 4 switches, where pins number 6, number 9, number 12, and number 15 are the parent.
How to Check a Relay
Checking the relay's good or bad will be faster if we have previously known the arrangement of the switch legs. Relay checks are carried out 2 times, namely when the relay is not given electric current and when the relay is supplied with electric current. The following is an example of checking an Omron 12 Volt DC relay.
1. Put the selector switch in the ohm x1 position.
2. Alternately check the leg connections:
- number 9 with 14 and 16
- number 15 with 8 and 10
- number 6 with 11 and 13
- number 12 with 5 and 7
- number A with B
3. Pay attention to the examination results above!
- Without being supplied with current, the legs numbered: 9 with 14, 15 with 8, 6 with 11, 12 with 5 must be connected to each other.
- If current is supplied, the legs must be connected to each other with numbers: 9 with 16, 15 with 10, 6 with 13, 12 with 7.
- Legs A and B must be in good contact whether or not current is applied.