ATO with Relay PCB

[tony73]

Hi all,

since 2 years I'm using DIY ATO 12V with a relay 12v 20a by CAR, like this:

I would like to know if it's possible to substitute it with a relay on pcb board, and which requirements needs to have.

Thanks
Antonio

 

[d0ughb0y]

you can use this. just search for single 5v relay arduino on ebay.

 

[mcgyvr]

you can use this. just search for single 5v relay arduino on ebay.

except that requires an extra 5V power supply.

To the OP..
Sure you can find a PCB mount one.. Its coil rating should be 12V and its contacts should be rated to switch the electrical ratings of your pump..
But why?.. Then you need a PCB,etc...

 

[tony73]

except that requires an extra 5V power supply.



To the OP..

Sure you can find a PCB mount one.. Its coil rating should be 12V and its contacts should be rated to switch the electrical ratings of your pump..

But why?.. Then you need a PCB,etc...

Because work is more clean

 

[d0ughb0y]

except that requires an extra 5V power supply.

To the OP..
Sure you can find a PCB mount one.. Its coil rating should be 12V and its contacts should be rated to switch the electrical ratings of your pump..
But why?.. Then you need a PCB,etc...

hmm, ok, just search for 12v relay then.

 

[d0ughb0y]

Is your circuit a 12v wall DC power supply, in series with ATO switch, then the relay switches the power to ATO pump?

if you want to keep 12v, then get 12v relay, but since 5v usb power supply are plenty and cheap (and you probably have a few extra laying around), it is easier (and cheaper) to get the 5v version of the relay.

 

[tony73]

But I'm not sure relay in picture above is fine, be cause relay's CAR has 4 pin to use, relay in The picture 3

 

[mcgyvr]

But I'm not sure relay in picture above is fine, be cause relay's CAR has 4 pin to use, relay in The picture 3

Actually its the same.. the CAR relay has 5 pins and so does the other.
You need 2 pins for the "coil" and 3 for the relay (C, NC, NO)

 

[d0ughb0y]

yes it will work.

your standard 5 pin automotive relay is this

for 4 pin relays, you just don't have the N/C connection.

The PCB has a 5v input to light up the LED. I don't think you need to connect that if you don't need the light. Simply use the same 4 connections. Two for coil input, and 2 for the AC voltage on the Normally Open terminals.

 

[mcgyvr]

The PCB has a 5v input to light up the LED. I don't think you need to connect that if you don't need the light. Simply use the same 4 connections. Two for coil input, and 2 for the AC voltage on the Normally Open terminals.

Many of those Chinese relay boards use an "optocoupler" to provide isolation or just a transistor between the 5V and the 12V sources. The 5V to the optocoupler/transistor is used to turn it on and allow the 12V (or whatever the other source voltage/relay coil is) to energize the relay coil
like this http://www.redrok.com/images/opto_relay_circuit_1
they might also have a LED on the 5V for visual indication.

But many do not too..

But heck I think the "CAR" relay solution is "more clean" anyways.