Understanding the Functionality of Relays: Exploring Input and Output Control

  • Thread starter booxcar
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In summary, relays can be used as voltage-controlled on-off switches and to control the output voltage to the load. The number of terminals on a relay determines the number of output "configurations" it can have. A single-pole single-throw relay has two terminals and can be used as an on-off switch, while a single-pole double-throw relay has three terminals and can have multiple "on" output values. However, a relay does not produce electricity and cannot control the output of a power supply. Other devices may be better suited for this purpose. Before using a relay, it is important to know the coil and switched voltage, as well as their AC/DC status and voltage levels.
  • #1
booxcar
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Hello all! I just had a quick question to ask about relays. I understand that you can use a relay as an input voltage-controlled on-off switch but it can also be used to control the output voltage to the load controlled by an input voltage, correct? If I am understanding everything correctly, since the pole and throw determines how many terminals there are and the number of terminals represent how many output 'configurations' can exist. So a single-pole single-throw has two terminals (Wiki says 4 terminals total if you include two terminals for the coil... don't really know what that means so for this example I'm going to ignore it :)) therefore the relay can be used as an on off switch whereas a single-pole double-throw switch (3 terminals not including the two terminals for the coil) can have a 0V 'off' output, as well as 2 more set 'on' output values. Is this correct? If so, I guess I kind of answered my own question.


Thanks,
boox
 
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  • #2
The output of a relay does not produce electricity. It merely shorts or opens two terminals.
 
  • #3
Yes, I understand this, the load will have a separate power supply. I was just wondering if the output of the power supply can be controlled with a relay...
 
  • #4
You have to periodically turn it on and off to do that.
 
  • #5
From what you've described I don't think a relay will do what you want. There are other devices that will do almost anything you can think of. If you can tell us a little more about your circuit, we'll be better able to help.

Is your coil voltage AC or DC? What voltage is it?
Likewise, is the switched voltage AC or DC and what is its voltage?
 

Related to Understanding the Functionality of Relays: Exploring Input and Output Control

1. What is the purpose of a relay?

A relay is an electrical switch that is used to control the flow of electricity through a circuit. It allows a low-power signal to control a high-power circuit, making it useful in applications where the control signal is not strong enough to directly switch the circuit.

2. How does a relay work?

A relay is made up of an electromagnet, a set of contacts, and a spring. When a small current flows through the electromagnet, it creates a magnetic field that pulls the contacts together, completing the circuit and allowing electricity to flow. When the current is removed, the spring pulls the contacts apart, breaking the circuit.

3. What is the difference between a relay and a switch?

While both a relay and a switch are used to control the flow of electricity, a switch is manually operated while a relay is controlled by an electrical signal. Additionally, a switch is typically used to control a low-power circuit, while a relay can handle higher amounts of power.

4. What are some common uses for relays?

Relays are commonly used in electronic devices, industrial machinery, and automotive applications. They are also used in household appliances such as refrigerators and air conditioners. In these applications, relays are used to control motors, lights, and other high-power components.

5. Are there different types of relays?

Yes, there are several types of relays, each designed for specific applications. These include electromagnetic relays, solid-state relays, thermal relays, and reed relays. Each type has its own unique characteristics and advantages, making them suitable for different uses.

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