I have an expanded Texecom Premier 88 which I installed myself. I now want to add some external PIRs and apart from the fact that the Texecom ones are relatively expensive, they are unsuitable for my needs anyway. I have identified a suitable sensor, but it does not have a volt free contact. From the information in my Texecom installation manual it appears that it is designed to only accept zone sensors with VFC. Nevertheless does anyone know if I can use one with a solid state output instead?

 

According to the sensor spec, it has a 22K pull-up resistor to 12V on the output, and has a transistor to switch a 100 ohm resistor to 0V when active. I made some measurements on one of the single contact zones (normally used for a fire sensor) and got 5V on the second 'T' terminal. When the fire sensor (N/C) was reconnected that terminal read 0V.

 

Does anyone know if connecting that terminal to 12V via the 22K resistor would cause a problem? If so maybe I can modify the sensor to turn it into an open collector output, but of course I'd like to avoid that if possible.

Edited October 19, 201312 yr by Dippy

I may suggest what correct option is to fit 12V relay board what gives you dry NC-NO contacts for Prem. 88. Fitting it in Prem 88 case should not be a problem.

As above use a t relay