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When a relay is not energized that means?
Closed
Relays are switches that open and close circuits electromechanically or electronically. When a relay contact is Normally Closed (NC), there is a closed contact when the relay is not energized. In either case, applying electrical current to the contacts will change their state.
How does current flow through a relay?
Current flowing through the coil of the relay creates a magnetic field which attracts a lever and changes the switch contacts. The coil current can be on or off so relays have two switch positions and most have double throw (changeover) switch contacts as shown in the diagram.
When power is applied what relays are energized?
A relay has a coil and one or more sets of contacts. When power is applied to the coil, the contact(s) change position. A relay with power applied to the coil is said to be energized.
Why does a relay need a minimum current?
Soon you add any resistor in series, relay will not be energised due to insufficient current. This parameter is more towards reliability specification of the relay. This is the minimum current, the relay expects to flow through the now shorted contacts when the relay is turned on (40 mA).
When does a relay contact become a closed contact?
When a relay contact is Normally Closed (NC), there is a closed contact when the relay is not energized. In either case, applying electrical current to the contacts will change their state.
How does the synchronizing circuit in a relay work?
Analog switching relays have a built in synchronizing circuit that controls the amount of output voltage as a function of the input voltage. This allows a Ramp-Up function of time to be on the load. Analog Switching relays turn OFF when the control voltage is removed and current in the load is near zero.
When does a zero switching relay turn on the load?
Zero-Switching Relays – relays turns ON the load when the control (minimum operating) voltage is applied and the voltage of the load is close to zero. Zero-Switching relays turn OFF the load when the control voltage is removed and the current in the load is close to zero.