Halloween Animatronics and Motion Sensor Switch

[eblttbf]

I want to replace the footpad switch with a motion sensor switch. The footpad is has a black wire and black/white stripped wire. I read 5 volts across the wires. The black/white shows as the positive.

I purchased a low voltage PIR. However PIR devices have 4 or 3 wires and I am stumped on how to wire the 2 wires from the switch to the 3 wire PIR device. I tried several ways with no luck.

Thanks in advance for any help!

 

[Martaine2005]

Hi, PIRs need a constant supply.
So L and N from supply (battery) and the 3rd is a switch line (sw). This is L to your device. The 4th, if it has one will be E (earth/ground).
The device and the PIR will share the N.

Martin

 

[eblttbf]

Hi Martin, I did not know that PIRs need a constant supply. The Halloween Animatronic is plugged into 120vac and there is a constant 5dc volts from the black/white wire, if you measure across the black/white and black wires. Once you connect those wires, they act like a wall switch and trigger the animatronic. So the negative black wire sees 5vdc and triggers.

The PIR has (+) L and (-) N and (out) or (sw) just as you described 3 wires.

So the question is, how can I take the 2 wires and match them to the 3 wires?

I am guessing if the PIR needs a constant supply , then I need to add a 5vdc battery pack just to supply the PIR. I would apply 5 volts across the (+) and (-) pins. Then the middle pin (out) or (sw) I would connect to the negative black wire? Do I have this correct?

Thanks in advance.
Jack

 

[Martaine2005]

Yes, you explained it better than I did!.
Your foot switch wire that has 5v can be connected to the PIR + (L) and and the - (N) to the PCB -. This can be found by locating a capacitor negative terminal (sometimes).
The other wire from your foot switch can then go to the 3rd terminal (sw).
This may or may not work depending on the type of foot switch used.
But I would give that a go first before we try adding separate supplies.

Martin

 

[Martaine2005]

Before you make any connections, can you open the foot switch?.
We need to know whether it is purely a switch interrupting the 5V supply. It may have a controller circuit, in which case wont work as I described. You threw me with “ getting 5V across both switch wires” and the black wire being N.

Martin

 

[eblttbf]

Hello Martin,
I opened the foot switch and it has a simple plunger.
So you suggested:
Use the animatronic black/wht(+) wire as my supply to the PIR(+) terminal
Use the animatronic black wire(-) as my PIR(sw) terminal.

I lost you on the PIR(-) to the PCB? Assume Printed Circuit Board? Which PCB? assume inside the aminatronics?

What to do with the PIR(-) terminal is the question.

So your suggestion to give the PIR its own 5volt supply is what I am going to try.. unless I can figure out what to connect the PIR(-) pin to. I would assume that I would need to open the animatronics find the PCB and seek a ground connection, something that I am avoiding since I am a not that knowledgeable.

Thanks in advance.
Jack

 

[Martaine2005]

Ok. Yes I was referring to a ground connection from the printed circuit board.
Adding a 5V supply is simple enough as you suggested. Leave the 5V wire from the foot switch disconnected. Connect the black foot switch wire to the OUT (sw).

Is there any reason you cannot put a mains voltage PIR on the mains 120V supply?.

Martin

 

[ChosunOne]

I purchased a low voltage PIR.

One question: What make & model low-voltage PIR did you purchase? Are you sure it works on 5 VDC? I'm asking because in my industry (security alarms), most PIRs need 12 VDC.

 

[Martaine2005]

Some of these PIRs work between 2.7V - 12V. They are online for £1.50.

 

[K8Philip]

Amazing idea! Has it worked out?