Power relays are a type of switch used within PCBs to open or close the circuit. Power relays are designed to handle higher voltages and higher currents. However, they can also be used with low voltages too.
What is the difference between latching and non-latching relays?
Both types of relays in similar in design and function, however, a significant difference between them is that a latching relay will remain in the last position it when it was last powered, whereas a non-latching goes back to its normal position. This makes each more type of relay suitable for different applications.
How to choose a power relay:
When choosing a relay, it is important to consider a number of specifications to ensure it is fit for purpose, some factors include:
- Coil voltage - the required voltage to actuate the switching mechanism. If a voltage is too high this could damage the components, if it is too low then it will not actuate
- Contact configuration - This is the state the contacts are in without power. For example SPST, single pole single throw
- Contact material - the relay contacts are available in many materials that have certain properties. Common materials are gold, silver, tin oxide and nickel
- Coil power - the amount of power (watts) the coil operates at. This must match the power in the circuit for correct function
- Coil resistance - the amount of resistance (ohms) in the circuit that the coil creates