Thread: Is a relay just a device that turns things on and off?
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Old 04-20-2001, 01:08 PM
stevebfl stevebfl is offline
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Location: Gainesville FL
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Yes and NO!

They are each current carrying switches that cause an action. They both also have other functions. A fuel pump relay decides that a motor is off because the rpms are below 300; thus potentially saving lives in an accident. It also shuts down the fuel pump at a certain rpm to save the motor.

The OVP relay uses a zener diode to short circuit all power surges over some voltage. It clips all voltage spikes through the fuse. So no, it is not just a device that turns things on and off!
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Steve Brotherton
Continental Imports
Gainesville FL
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