Relays: Single Throw vs Double Throw

Relays: www.rspsupply....
Today we want to talk in a little more about relays. Specifically, about NO contacts and NC contacts. Why does it matter and how does it affect the type of relay we might need.
* All relays have a set of contacts, these contacts allow electricity to pass through them when they are in the closed position (or when they are touching each other)
* Depending on the function we need in a relay, we can use a NO contact or a normally closed contact.
o Normally Open Contacts
* The contacts will not be touching each other in it’s normal state (that is when the coil is not acting on the contact)
* When the coil is energized, the normally open contact will be pulled against the other stationary contact into a closed state
* At this point, electricity will be able to pass through the contacts.
* A relay that is normally open is providing power when the coil is energized.
* Lets look at how this works
o Normally closed contacts
* The contacts WILL be touching each other in the relay’s normal state (when the coil is not acting on the contacts)
* When the coil is energized, the contact will be pull away from the other stationary contact, thus opening the circuit.
* At this point electricity that was previously flowing when the contacts were closed, will no longer be flowing when the coil is energized.
* It is important to note that the contact side of a normally closed relay will be energized. So at any given point either the coil side or contact side will have power to it.
* Let me show you how this works
o Double Throw Relay
* There are also relays that give us both options in the same relay. This is called a double throw relay
* What is important to not about a double throw relay is that we have the ability to control two different circuits with the same relay.
* So a double throw relay will let us wire one circuit to the normally open side, and another circuit to the normally closed side.
* When the coil is energized the normally closed contact will open and the normally open side will close.
* They both use the same power, or common.
o Let’s take a look at a few examples to better demonstrate how this works.
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[@sydneybeaa]

I know nothing about circuitry, and looked this up for my dad. Even I understood the basics, great job!

[@RSPSupply]

Glad it was helpful!

[@democracyforall]

@@RSPSupply how will we create a circuit with a water sensor so that as the sensor touches the water the relay will energise and create power so the motor will also energise with the first diagrame of normally open diagrame you talke about, If you can do that , it will be great.

[@senkuraj]

I became the addict to RSP. This is the channel which satisfied and cleared all my doubts. Very nice explanation with physical parts. One consider, pls show the parts/components in closer view for more time for taking a look of the parts.

[@mdarifurrahmankhandoker6180]

Excellent video!

[@solomonkolawole8993]

Super explanatory Thank you!

[@daaldertechniekdruktemaker2630]

Very useful! Thanks you for sharing!

[@jollyscaria1922]

Vrey good normalopen normly closed relay

[@davidjacobs8117]

What program are you using for the presented diagram?

[@zarchosa8978]

thank you so much for the tutorial

[@RSPSupply]

You're welcome. Thanks for watching

[@ledzeppelin1212]

Great video. Thank you!

[@JaceD4V1S88]

so im trying to connect a horn to my security system, i have one wire thats 12v for the beeps when i lock and unlock, and another 12v wire that pulses the horn when alarm is triggered, i need to connect those two wires to a relay that goes to a single wire to the horn so the horn does both the honk when i lock and pulse when it goes off.

[@RSPSupply]

Response: Thank you for reaching out with your question! It sounds like you're looking to integrate a horn into your security system using a relay to control both the beep functionality for locking/unlocking and the pulse function for the alarm trigger. To achieve this, you can use a double throw relay (also known as a changeover relay). With a double throw relay, you can control two separate circuits with the same relay. Here's how you can wire it: 1. Connect the wire that provides 12V for the beeps when you lock and unlock to the normally open (NO) contact of the relay. 2. Connect the wire that pulses the horn when the alarm is triggered to the normally closed (NC) contact of the relay. 3. Connect the common (COM) terminal of the relay to the wire leading to the horn. When the relay coil is energized (e.g., when your security system activates), it will switch the contacts. This means that when the security system is activated, the relay will disconnect the 12V for the beeps and connect the wire that pulses the horn, causing the horn to pulse. Conversely, when the security system is not activated, the relay will connect the wire for the beeps, allowing the horn to beep when you lock and unlock. Make sure to properly size the relay and ensure that it can handle the current required by your horn. Additionally, consider using appropriate fuse protection for each circuit to prevent damage to your security system or horn in case of a fault. If you need further assistance or have any other questions, feel free to ask!

[@Za3eeem9]

Thanks

[@Frank-ServiceTech]

thank you josh

[@eknuds]

What if I want to build a circuit that allows me to choose between two different 120v AC power sources? To switch between primary and backup power, for example.

[@4valves551]

what is the output voltage of this relays?is it possible to get 230V/AC supply on output???

[@brianjones6007]

Which relay(s) would one use to switch from charging 1 battery to another?

[@s.m.i.e3283]

What is the 5v sugar cube coil resistance

[@hunqiangng2511]

May i know why we need to use two throw ? can some one explain it ?

[@garyexgrunt7902]

I am trying to figure out how to use a double pole single pole relay for a CNC retrofit . I want to control the estop with the original e-stop on the machine or the e-stop of Mach-3 as now the spindle is the only thing that stops when the machine e-stop is used and the bed of the machine stops when the mach3 is used. either still running is dangerous.

[@bitebonumbere1426]

Please add subtitles to your videos

[@dimak.9906]

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