Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.

Relay Coil Impedence

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Relay Coil Impedence | 1 March, 2007

Kindly explain to me how to calculate 24V DC Relay Coil Impedence for a 2PDT Relay.

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Relay Coil Impedence | 1 March, 2007

You shouldn't be worrying about "impedance" on a DC relay. Just measure the resistance with a Voltmeter/Ohmmeter. If you need to know the current draw, it will be 24/resistance

The impedance of an AC relay changes as the armature moves from the "off" to "on" positions, and can only be CALCULATED by disassembly, careful measurement of all parts and use of finite-element analysis or analytical methods to calculate the magnetic flux paths. You can use an impedance bridge to measure the "off" inductance, and then manually move the armature to measure the "on" inductance.

(Probably more than you wanted to know)

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Relay Coil Impedence | 2 March, 2007

Ohm's law in action! :-)

Thanks for the EE refresher.

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