Autona 2250 circuit

Hi, first post here.

Anyone know possible source of the circuit diagram for my 15 year old control unit please? It's an Autona Series 200, model 2250. Web searches for Autona Limited, Princess Risborough, lead to an unrecognised phone number. This morning I'll try Chiltern Electronics who are in the same location, but I'm not too hopeful.

The re-entry delay on mine has failed. Probably down to my impatience. I removed the front door reed relay sensor door because it had become unreliable, often 'sticking' in its passive state instead of triggering the alarm re-entry delay warning. After the replacement the re-entry delay has failed. Instead of a 30 second warning while I disarm it with my code, the siren sounds immediately.

I think I must have damaged that section of circuitry while soldering in the reed. I did check that the passive voltages were zero, but that's the only cause I can think of.

So I might dust off my shed workshop bench and try making an add-on to provide this lost functionality. Access to the circuit diagram would be a great help.

There's one other longshot approach I'm trying in parallel. By removing 4 screws I was able to get a good look at the circuit board. Its main active component is a PIC16FC4. I know virtually nothing about PICs, but just in case that *has* become faulty I thought it worth dropping in a replacement. I couldn't find that specific one in stock anywhere so I've taken a gamble and ordered a PIC16C54-XTI/P (8BIT CMOS MCU, 16C54, DIP18) at £3.64 from CPC.

Reply to
Terry Pinnell
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A PIC chip is a computer chip with custom "programming" loaded into it. Also called a "microcontroller".

Your replacement of that chip would be like replacing your fully functioning desktop computer with a new computer which DOES NOT HAVE ANY SOFTWARE ON IT! It is not going to work.

Don't mess with the control unit.

The problem is what you have changed and that is the door. It probably had an "end of line resistor" connected to the switch in the door. The new switch needs one as well.

If you no longer have the old door and the old switch, I suggest you call an alarm company and have them come out and fix the door switch. They would know or would be able to figure out what value resistor should be wired into the circuit.

Reply to

Thanks Bill.

Yes, that was dumb. I realised my mistake shortly after getting CPC's order confirmation yesterday!

And that wasn't the only dumb thing I did. Part way through breadboarding my proposed add-in, I needed to test a few voltages and resistances at the CU connections. (Because the circuit would have to be more complex than I described, to maintain the EXIT delay.) In the course of doing that I discovered the cause of the problem: I'd swapped the anti-tamper loop and delay loop!

So, much wasted time but a happy ending ;-)

Reply to
Terry Pinnell

If it's 15 years old and not functioning properly I imagine it's time to ge= t something new and modern.

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