EN
Before choosing an electromagnetic current relay, you must first understand the necessary conditions:
1. The power supply voltage of the control circuit and the maximum current that can be provided;
2. Voltage and current in the controlled circuit;
3. How many sets and types of contacts are needed for the controlled circuit. When selecting a relay, 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 enough working current to the relay, otherwise the relay will be unstable when it is closed;
The following is a strategy to understand the necessary conditions of electromagnetic current relays:
1. Access to information:
After consulting the relevant materials to determine the conditions of use, you can search for relevant materials to find out the model and specification number of the required relay. If you have a relay in hand, you can check whether it can be used based on the data. Finally, consider whether the size is appropriate;
2. Pay attention to the volume of the appliance:
If it is used for general electrical appliances, in addition to the cabinet volume, small relays mainly consider the circuit board installation layout. For small electrical appliances, such as toys and remote control devices, ultra-small relay products should be used;
3. Technical parameters of electromagnetic current relay:
(1) Rated working voltage:
It refers to the voltage required by the coil when the relay is working normally. Depending on the model of the relay, it can be AC voltage or DC voltage;
(2) DC resistance:
Refers to the DC resistance of the coil in the relay, which can be measured by a multimeter;
(3) Pull-in current:
It refers to the minimum current that the relay can produce the pull-in action. In normal use, the given current must be slightly larger than the pull-in current, so that the relay can work stably. As for the working voltage applied to the coil, generally do not exceed 1.5 times the rated working voltage, otherwise it will generate a larger current and burn the coil;
(4) Release current:
It refers to the maximum current that the relay generates to release the action. When the current in the pull-in state of the relay is reduced to a certain level, the relay will return to the unpowered release state. The current at this time is much smaller than the pull-in current;
(5) Contact switching voltage and current:
Refers to the voltage and current that the relay allows to load. It determines the magnitude of the voltage and current that the relay can control, and this value cannot be exceeded during use, otherwise it is easy to damage the contacts of the relay.
