Electrical relay in a circuit?
I already know that a relay is one of the simplest,cheapest and one of the most widely used component in the electrical or electronic world.
what i want to know is;
(1)Why bother to use a small amount of current or voltage to turn on a relay which would eventually control a device that uses far more current than which was used to turn it(relay) on.
Wouldn’t it be easier and less time consuming to connect the device straight to it’s source(supply voltage) thus bypassing any relay.
What is the pros and cons of such a configuration?
Tagged with: electronic world • pros and cons • source supply • supply voltage
Filed under: Electronic Circuit Components
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That is not the only use of relays, they can also be used (among other things) to separate the power and switching voltages and to change the logical sense of a switch – turning something on can turn another off.
Example:
A switch is attached to a float to control water level.
1.If the switch runs through a relay (or other isolation device) we can make a small, safe voltage through a cheap low current switch, turn on a relay and run a high voltage 3 phase pump. we only need high current wire from the supply through the relay (which can be mounted next to the supply or pump) and to the pump.
2. Without a relay we would have to have an expensively designed switch capable of switching tens or hundreds of amps and 3 phases concurrently. We also would have to run expensive high current wire all the way from the supply, through the switch and then to the pump.
Relays are increasingly replaced with ’solid state’ switching, electronic devices with no moving parts to wear out or fail