Correct selection of power relay four steps

1, measuring contact resistance

With the universal form of the resistance profile measurement, normally closed contact and fixed point of resistance, the resistance should be 0, (with a more accurate way of measuring contact resistance less than 100 Ohm); and the normally open contact point and the resistance is infinite. It can be distinguished from the normally closed contact, the normally open contact.

2, measuring coil resistance

The available universal meter to measure the power of R * 10 ohm relay coil resistance, so as to judge whether there exists the coil open circuit phenomenon.

3, measuring voltage and pull pull current

To find adjustable voltage regulator and current meter, power relay to enter a set of voltage, and in the power supply circuit in series ammeter for monitoring. Slowly increase the power supply voltage, power and relay voice heard, write down the pull in voltage and pull current. For the sake of accuracy, you can try several times and the mean value.

4, measure the release voltage and release current

Is the connection test as mentioned above, when the power relay occurred after suction and then gradually reduce the power supply voltage when the power relay again release sound when the voltage and current of the mind, may try a few times and achieved the average release voltage and current release. The general situation of five steps, release voltage power relay is about 10 ~ 50% in the pull in voltage, if the voltage is too small (the release of the pull in voltage of less than 1/10), cannot be used normally, it will threaten the stability of the circuit, the work is not reliable. Relay manufacturers

1 understand the necessary conditions

The control circuit of the power supply voltage of five steps, can provide the maximum current;

Power relay: voltage and current in the controlled circuit;

What kind of contacts are needed in a power relay. The power supply voltage of the general control circuit can be used as the basis for selecting the power relay. The control circuit should be able to provide adequate working current to power relay or power relay is not stable.

2 access to relevant information to determine the conditions of use, you can find relevant information to identify the need to use five steps of the power relay models and specifications. If you have a power relay, you can check whether the data can be used. Finally consider the size is appropriate.

3 note the volume of appliances. If used for general electrical appliances, in addition to taking into account the volume of the chassis, the main consideration of small power relay circuit board installation layout. For small appliances, such as toys, remote control devices should be used for ultra small power relay products.