Re: Autona 2250 circuit

[Bill <Nomailorspam@xxxxxxxxx>]

In article <4sprr7p21otpif9hr4l127gioirtbg7aja@xxxxxxx>,
terrypingm@xxxxxxxxxxxxxxx says...
>
> 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.

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.