[tech] Door Circuitry

[Mark Tearle]

On Mon, 30 Aug 2010, Adrian Chadd wrote:
> On Mon, Aug 30, 2010, Bob Adamson wrote:
>> Well...this could have saved several hours of head scratching...
>>
>> Door relay is alive again. Fixing the short in the lock and replacing the
>> fuse in the modem fixed it, though it took a bit longer to sort out the
>> power issues. Turns out the solenoid and modem are pretty power hungry,
>> and don't want to work with a wall wart.
>>
>> For future reference, you send ATH1F over serial to trigger the relay.
>>
>> Bob
>>
>> On Sun, 29 Aug 2010, James Andrewartha wrote:
>>
>>> On Sun, 29 Aug 2010, David Adam wrote:
>>>
>>>> On Sun, 29 Aug 2010, David Adam wrote:
>>>>
>>>>> On Sun, 29 Aug 2010, Bob Adamson wrote:
>>>>>> Sad news - our door relay has kicked the bucket. Somehow the electronic lock
>>>>>> got a short in it, killing the modem (!) that drives the relay. Of course,
>>>>>> being UCC, this modem was a complete box of hackery. Adrian and myself are
>>>>>> working on a simple circuit to replace it, but haven't had any luck yet.
>>>>>>
>>>>>> If anyone knows anything about how the old setup worked (particularly the
>>>>>> success/failure sensing in the binary) please give me a yell.
>>>>>
>>>>>> From http://www.ucc.gu.uwa.edu.au/services/door.ucc
>>>>>   The door lock is switched using the On-Hook relay of a modem. This
>>>>>   provides a cheap, reliable serial interface to the door lock.
>>>>>
>>>>> You need to send ATD (or possibly ATH) down the serial line to make the
>>>>> modem pick up the phone line. The thought occurs that you probably didn't
>>>>> know that this afternoon which may have been why you couldn't get it to work
>>>>> :-)
>>>>
>>>> Actually it's A0. I think.
>>>
>>> strings /usr/sbin/opendoor suggests 'ATH1F' and 'ATH0F'.
>>>

James is right.

>From memory, the power switching side is not connected to the modem electronics
so it should be fine.  I think the speed of the interface to the modem is
1200 baud.

So it appears the strike has given up the ghost as after many years of 
faithful service.  I believe Jaycar sell replacement strikes.

http://www.jaycar.com.au/productResults.asp?keywords=strike&keyform=KEYWORD&SUBMIT.x=0&SUBMIT.y=0

Model selection is left as an exercise for the reader.


Mark
-- 
Mark Tearle - mtearle at ucc.gu.uwa.edu.au

Fish!