Using the 12V for a relay

[brucecampbell]

Hi all, 

I am using all four contacts on my HC800.
I am also using two of the relays
for one of the relays, I am using the 12V and GND from one of the contacts already in use.
This Contact is giving me some trouble - it is hooked up to a motion sensor and on occasions this motion sensor is triggering several hundred times over a few seconds - it really ties the system in knots.
Just wondering if using the same 12V slot for a contact  and also for a relay could be causing this problem?

To help debug I have moved the relay to another contact to see if there is a difference in behaviour - but after some advice to find out if physical connections this way are ok?

Cheers.

 

 

[Matt Lowe]

you may be drawing too much current from the controller. The 12volt rail is not meant to supply much power. if you have 4 contacts you might be hitting the limiting. i would suggest adding an external power and cut the ground with the relay.

[brucecampbell]

Cool, I will try that - as I have plenty of other power supplies available to use.

Help please on the wire config??

Power supply 12V+   -->   HC's COM
HC's NO  -->   Relay +
Power Supply 12V-  -->  Relay -

Is it as simple as this?

Thanks.

 

[thegreatheed]

3 minutes ago, brucecampbell said:

Cool, I will try that - as I have plenty of other power supplies available to use.

Help please on the wire config??

Power supply 12V+   -->   HC's COM
HC's NO  -->   Relay +
Power Supply 12V-  -->  Relay -

Is it as simple as this?

Thanks.

 

No. You don't want to be switching on and off the power supply (running it through the relay will make it switch on and off).

Controller NO and COM will be a relay switch, used to control something. For a motion sensor you need the controller to sense what it is doing, so you wouldn't wire into the controller relay AT ALL. Wire it into the contact sensor.

Power supply 12v and grd -> Motion 12v and grd
Motion out +/-  -> Controller contact SIG/GRD

[brucecampbell]

5 minutes ago, thegreatheed said:

No. You don't want to be switching on and off the power supply (running it through the relay will make it switch on and off).

Controller NO and COM will be a relay switch, used to control something. For a motion sensor you need the controller to sense what it is doing, so you wouldn't wire into the controller relay AT ALL. Wire it into the contact sensor.

Power supply 12v and grd -> Motion 12v and grd
Motion out +/-  -> Controller contact SIG/GRD

Thanks - I am running a relay, not motion sensor - so I just need 12 volts to switch the relay - no SIG is needed

I want the 12V to come from an external power supply instead of the HC800.
So somehow the 12V needs to be on the switched circuit.

(The original mention of the motion sensor was due to me stealing 12V for the relay from the same 12V output as a motion sensor is using for a contact point)

[thegreatheed]

Oh, the motion sensor is giving issues, but it not what you're changing. You're changing a relay because the motion is malfunctioning.

Yes, for just a relay, it's that simple and your previous example is correct.

[brucecampbell]

1 minute ago, thegreatheed said:

Oh, the motion sensor is giving issues, but it not what you're changing. You're changing a relay because the motion is malfunctioning.

Yes, for just a relay, it's that simple and your previous example is correct.

Correct - thanks - yes the motion sensor hooked up to the 12V and SIG was playing up - I'm now assuming it was due to voltage being drained through so many connections to the 12V onthe one controller.
So I am removing the relay from the 12V loop and using an external power supply.

Cool - I will change my connections and hope for the best!

Thanks for the help!