My 20 year old burglar alarm control has developed a fault that I've spent the last couple of days trying to fix. Before I ditch it and go through the hassle of installing a new one I'm seeking help here please.
Q1: An extreme longshot as I researched in 2012 but the company had long folded, but... Anyone have or know a source of the circuit diagram for the Autona 2250 Control Unit?
FWIW, screenshot inside the control unit's case
Q2: A useful second best would be *any* circuit of a bog-standard, commercial, wired unit designed for a series of normally closed microswitches.
I made this one myself about 35 years ago and *suspect* that it will be broadly similar, but I'd like to eliminate guesswork:
It's being triggered spuriously. Two successive nights, 01:05 and 12:35. During late stages of trouble-shooting (i.e. after checking all switches) I found that I could trigger it by switching on light of the cupboard in which unit is mounted, powered from same 240V source.
I suspect a failed capacitor. But I don't relish dismantling it to get at the two PCBs and even if I did I doubt I'd find it.
Q3: Using the access I have to the power supplies (240 V AC, 15 V AC,
13V DC) and the pairs of wires from the string of N/C microswitches, what transient suppression should I try adding at one or more of these external points please, and in what priority?Terry, East Grinstead, UK