The relay measuring contact resistance uses the resistance file of the universal meter to measure the normally closed contact and the dynamic point resistance, and its resistance value should be 0; while the resistance of the normally open contact and the moving point is infinite. This makes it possible to distinguish which is a normally closed contact and which is a normally open contact. Let's take a look at the Automotive Relay Manufacturer!
The measuring coil can be used to measure the resistance value of the relay coil by the universal meter R×10 Ω, thereby judging whether the coil has an open circuit.
Measure the pull-in voltage and pull-in current to find the adjustable power supply and ammeter, input a set of voltage to the relay, and connect the current meter in the power supply circuit for monitoring. Slowly increase the power supply voltage and record the pull-in voltage and pull-in current when you hear the relay pick-up sound. For accuracy, you can try to average and try several times.
Measuring the release voltage and the release current are also connected as described above. When the Power Relay is pulled in, the supply voltage is gradually reduced. When the relay is heard again, record the voltage and current at this time. The average release voltage and release current were obtained several times. Under normal circumstances, the release voltage of the relay is about 10~50% of the pull-in voltage. If the release voltage is too small (less than 1/10 of the pull-in voltage), it will not work properly. This poses a threat to the stability of the circuit and is unreliable.
