This article shows technical terms related to relays.
Operating coil
１．Coil designation
| Single stable type | Single-coil latching type | Double-coil latching type | ||
|---|---|---|---|---|
| Non-polarized | Polarized | Four terminals | Three terminals | |
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- A black coil represents the energited state. For latching relays,schematic diagrams generally show the coil in its reset state. Therefor, the coil symbol is also shown for the reset coil in its reset state.
2.Rated Coil voltage
The coil rated voltage represents a reference voltage applied to the operating coil for normal use of the relay. The service life of the relay and product specification is made based on rated coil voltage.
3.Rated operating current
The value of current flow in the coil when nominal voltage is applied to the coil.
4.Rated operating power
The value of power used by the coil at rated voltage the coil (rated operating power=rated coil voltage×rated operating current).
5.Coil resistance
This is the DC resistance of coil in DC coil type relays under temperature conditions specified in catalogs. Under normal circumstances, a coil resistance value is indicated at 20°C. Please note that coil resistance values for some relays are shown whetherdifferent temperatures.
6.Operate voltage (set voltage)
This is the voltage at which the relay is operated. An input voltage to the coil of the relay in open state is gradually increased to reach the operating voltage, which makes the relay to shift to operating state. In the case of the latching relay, a voltage causes the relay to shift from the reset state to set state is referred to as the set voltage.
7.Release voltage (reset voltage)
The release voltage is the voltage at which the relay is unoperated.. An input voltage to the coil of the relay in operating state is gradually decreased to reach the release voltage, which causes the relay to shift to unoperated state. In the case of the latching relay, an input voltage to the reset coil is increased (in case of single-coil latching relay, an input voltage with a reverse polarity is increased) to put the relay back to reset state, and a voltage that causes the relay to shift to reset state is referred to as the reset voltage. The operate voltage (set voltage) and release voltage (reset voltage) are usually defined as voltages at 20°C. For some relays, these voltages at 25°C are specified. Please check the voltage values listed in catalogs.
8.Maximum applied voltage
The maximum applied voltage is the maximum voltage that can be applied to the operating coil. However, continuously applying this maximum voltage to the operating coil is not allowed. The maximum applied voltage varies depending on the ambient temperature. Please check the maximum applied voltage values listed in catalogs.
