I have a wireless security door sensor, which has a reed switch, and I'm trying to replace the reed switch with my existing wired security door sensors (thus not having to mount the wireless door sensor on my door when I already have one there).
I soldered two short wires to where the reed switch connects to the circuit board, and when I touch the two wires, it completes the circuit as expected. However, if I connect these wires to my wired sensor via 30' wire, then when I first close the circuit, the wireless sensor registers it as closed, but when I break the circuit, it continues to register the sensor as closed.
I confirmed with a multimeter that the circuit opens/closes when I trigger the door sensor. I also just used a 20' wire without a wired sensor on the end, confirming it fails in that case. When I use an 8' wire, everything works as it should.
I'm using 22/2 unshielded wire, so I'm wondering if this, combined with the distance is my issue.
Can anyone with more electronics experience explain why this would be failing? And, are there any solutions with my existing wiring?
Best Answer
The sensor input is working with ac voltage.
Wires that are not working have a higher capacity that triggers the alarm. The weird not releasing issue is caused by the sensor input hysteresis.
No easy fix, just to change the wire.
Edit:
Actually there is but it works only if not battery powered , use the sensor to drive a reed relay placed near the alarm input or a mosfet transistor but this depends on the input.