Basic Relay working- a confusing thought

Thread Starter

ManasiDNair

Joined Oct 26, 2017
8
demo.JPG Hi all,

I wish to operate a chain of relays to be ON at the same time and OFF at the same time. From what I understand, alternating the connection between the input pin and the ground pins will cause the relay to alternate between the connection of NO Normally open) and NC Normally closed) outputs. Could you shed some idea on how to simultaneously switch all relays together(all relays- same state at the same time) without the need of Arduino/ pi etc?
I drew a figure (have shown only 4 inputs) if that could explain my question more clearly.
Thanks a ton for reading through my post. I'll really appreciate it if anyone could help me with this.
 

Thread Starter

ManasiDNair

Joined Oct 26, 2017
8
A simple on/off switch and parallel the inputs, the input appears to be some type of opto isolator.
Max.
Hi Sir,

But there are 24 inputs (24 relays).
The purpose of this project is to make a switching circuit that has to switch the operation from one 24 pin circuit to another 24 pin circuit. (Using the NC and NO terminals of 24 relays). The idea is to control the operation of all the relays using just a single operation.

When the input 1 is connected to ground, relay 1 output moves from Normally closed(NC) to Normally open(NO) position thereby switching 1'st pin of the connection from one circuit to another.
When the input 2 is connected to ground, the relay 2 output mves from Normally closed(NC) to Normally open(NO) position thereby switching 2'nd pin of the connection from one circuit to another.
Similarly we have to switch all the 24 pins simultaneously to change the full output connection from one circuit to another.

Would you please explain about what you meant by a single on/off switch by parallel inputs? I didn't find a 24 way switch for that purpose. (A simple 3 way switch with parallel inputs would have been helpful if we had to control only 3 signals at a time. Here, the 24 inputs is the problem).

As I understand, the inputs are nothing but merely the coils that electromagnetically initiates relay output switching operation. (In the electromagnetic relay shown above)

I wish to know if we could switch all the 24 relay outputs simultaneously.

I really hope I'm able to convey my problem that I'm seeking the solution for. In case there is anything wrong in my understanding or clarity, please do correct me.

Thanks for your time,
Manasi
 

AlbertHall

Joined Jun 4, 2014
12,345
Connect all 24 inputs to the relay boards together, so now just one wire, and connect the switch to that one connection.
Are you actually using relay boards as in the picture or something else?
We are basing our answers on you using boards like the one in your picture.
 

panic mode

Joined Oct 10, 2011
2,715
1. Connect 5V power to Vcc and GND
2. Inputs are supposed to be turned on by Arduino so logic1 should turn it on. You can simulate this by connecting one of the inputs to Vcc (5V). you should hear relay clicking. You can use continuity check on the relay contact side to confirm it works as expected.
3. Connect common terminals of the relay contact side to power source (such as 24VDC). Connect NO (or NC if you like) to load. connect other end of load to negative side of that power source
4. if you wish to turn on more than one relay at once, just drive corresponding inputs at the same time
 

MaxHeadRoom

Joined Jul 18, 2013
28,617
But there are 24 inputs (24 relays).
The purpose of this project is to make a switching circuit that has to switch the operation from one 24 pin circuit to another 24 pin circuit. (Using the NC and NO terminals of 24 relays). The idea is to control the operation of all the relays using just a single operation.

As I understand, the inputs are nothing but merely the coils that electromagnetically initiates relay output switching operation. (In the electromagnetic relay shown above)

Manasi
I understand what you want to do, all the inputs do is sink to common.
If you parallel all of them up and connect a SPST to all should work, you can always confirm it with 2 or 3.
But I see no reason why it would not work.
You don't need a 24v position switch, wire each input in parallel and connect to a common terminal block then take the two wires to a single single pole, single throw switch.
Max.
 

Rahulk70

Joined Dec 16, 2016
536
Hi,
As our members have said above you could just connect all the inputs to a common point and then make it work. What MaxHeadRoom has mentioned above is a really simple and good method. Or you could go for something like this pre-built, but little more complex and expensive I guess.
http://relaypros.com/Relay/Relay/CAT_RELAY24

What do you intent to control with the above relay system?
 

Rahulk70

Joined Dec 16, 2016
536
I understand what you want to do, all the inputs do is sink to common.
If you parallel all of them up and connect a SPST to all should work, you can always confirm it with 2 or 3.
But I see no reason why it would not work.
You don't need a 24v position switch, wire each input in parallel and connect to a common terminal block then take the two wires to a single single pole, single throw switch.
Max.
Something I still don't get is the OP says he/she intents to control the 24 inputs to control another 24 input circuit and keep all the 24 pins HIGH at the same time when powered. If thats the case wouldn't it be easier to just short al the 24 pins in first and second circuit and just use one relay? Well of course unless he/she plans to control individual relay later on.
 

Thread Starter

ManasiDNair

Joined Oct 26, 2017
8
Connect all 24 inputs to the relay boards together, so now just one wire, and connect the switch to that one connection.
Are you actually using relay boards as in the picture or something else?
We are basing our answers on you using boards like the one in your picture.
Thank you. But if all inputs are connected together as shown in the figure, I was thinking if I will be thereby causing a short circuit. Will this connection cause some damage or is it just supposed to be a ground connection?
Expecting your comment,
Manasi
demo2.JPG
 

Thread Starter

ManasiDNair

Joined Oct 26, 2017
8
I understand what you want to do, all the inputs do is sink to common.
If you parallel all of them up and connect a SPST to all should work, you can always confirm it with 2 or 3.
But I see no reason why it would not work.
You don't need a 24v position switch, wire each input in parallel and connect to a common terminal block then take the two wires to a single single pole, single throw switch.
Max.
Thanks, did you mean something like this will work perfect? (That rectangle is supposed to be a terminal block :) . The output side of the terminal block is shorted together and taken through a single switch to ground connection) . Is that good?
I was just fearing if this will be a short circuit!
demo2.JPG
 

Thread Starter

ManasiDNair

Joined Oct 26, 2017
8
Something I still don't get is the OP says he/she intents to control the 24 inputs to control another 24 input circuit and keep all the 24 pins HIGH at the same time when powered. If thats the case wouldn't it be easier to just short al the 24 pins in first and second circuit and just use one relay? Well of course unless he/she plans to control individual relay later on.
No, they are the 24 signals that comes from one machine to a common communication bus. By 'switching' operation, I intend to switch the bus communication from one machine to another. As in, the communication bus will now receive signals from Machine 2 and not from Machine 1. If the switch is turned back to the previous position, the bus now receives signal from Machine 1 and not from Machine 2. That's the idea.
 

Rahulk70

Joined Dec 16, 2016
536
No, they are the 24 signals that comes from one machine to a common communication bus. By 'switching' operation, I intend to switch the bus communication from one machine to another. As in, the communication bus will now receive signals from Machine 2 and not from Machine 1. If the switch is turned back to the previous position, the bus now receives signal from Machine 1 and not from Machine 2. That's the idea.
Hi,
So from what I understood you intend to control Machine 1 when the relay is ON and Machine 2 when relay is OFF. Also all the 24 signals are from 24 individual pins right?
 
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