What are the factors that should be considered when selecting the power relay?:
1) the voltage and current in the controlled circuit;
2) when the power relay is selected, the power supply voltage of the general control circuit can be used as the basis for selection. The control circuit should be able to provide sufficient operating current to the power relay, otherwise the relay pull in is unstable;
3) how many sets of contacts does a control circuit require?;
4) control the power supply voltage of the circuit, can provide the maximum current.