I’m working on a personal project wiring a 12v battery to an electric car antenna which I want to use to open and close a chicken coop door.
The car antenna has 3 cables, one earth and two power cables. When power is applied to one of the power cables it retracts and when power is applied to both cables it extends.

What I’m trying to do is automate the process of opening and closing the chicken coop door using a 12v relay (see image which is a 5v version) which is connected to ‘Alexa’. so I can set the coop door to both run on a timer and be voiced activated.
I’ve never used a relay before and I’m a bit confused as to how to get the relay setup. I have it powered up, it’s just the connecting of the cables from the NO, NC and COM ports to the antenna motor that’s had me a bit stumped.

Any pointers would be gratefully accepted.

Thanks

 

Does the antenna mechanism have limit switches to disconnect the power at each end of its travel? If so, wire it like this:
Motor common to battery negative.
Relay COM to battery positive.
Relay NO to the "door open" motor wire.
Relay NC to the "door close" motor wire.
This is the simplest setup but the door will only remain open as long as the relay is energized. If it is running from the AC mains, this will be no problem, but if you are using a battery, you will need to control two separate momentarily energized relays using two control channels.

Good luck.
Keith

 

Hi, thanks for your reply.

It’s running off a battery which I intend to charge via a solar panel and the antenna does indeed have limit switches.
I don’t really understand what you mean by “ two separate momentarily energized relays using two control channels”

Apologies for my ignorance but relays are new to me.

This is the actual relay I’m using.
MHCOZY Updated WiFi Wireless Smart Switch Inching Self-Locking Relay Module,Set Inching Time from 0.5 Second to 1 Hour,be Applied to Access Control,DIY WiFi Garage Door Opener (7-32V with Shell)
https://www.amazon.co.uk/dp/B07QZQGJB1/ref=cm_sw_r_cp_api_fabc_tAxVFbTCBN6X0?_encoding=UTF8&psc=1

Thanks

 

Hi Keith,

please ignore my previous reply. I've managed to work it out through trial and error.

As you suggested....
Motor common to battery negative. - Yes
Relay COM to battery positive. - Yes
Relay NO to the "door open" motor wire. - Yes
Relay NC to the "door close" motor wire. - I've skipped this and wired the "door close" directly to the battery positive. It now works as I had hoped.

I had forgotten to mention that the antenna retracts when power is switched off and extends when powered up, so essentially I was looking for an on/off 12v wifi switch.

Again, many thanks for your help. My chickens thank you too!

 

I'm happy you got it working.