Re: Alarm question

[four.rings@MCIONE.com]

Timothy, since I received a number of similar alarm questions, I am
gonna answer them in one post to the list. I hope you don't object.

Timothy King wrote:
> 
> Hi Igor --
>I saved a bunch of
> your alarm posts over the past year(s) and I notice a common theme:
> Prestige. You seem to think they are a great value. Excellent. Autotoys on
> the web has the Prestige Platinum APS 500+ on special for $89:
> http://www.autotoys.com/sec.htm

It's a great price, Timothy.
 
> My question is, do you need additional relays for the Audi power lock
> system? The alarm specs say it works with positive an negative doorlock
> systems, but that reverse polarity and five wire systems need relays.

1. Audi uses pneumatic servos for locking and unlocking the doors.
2. All alarms (Prestige included), provide either negative or positive
pulse upon arming/disarming themselves.
3. In order for the electrical pulse to operate a pneumatic servo you
need a special high rpm pack-and-pinion motor assy, called an
"actuator". It gets connected mechanically to the door lock lever and
electrically to the alarm's pulsed output.
5. Most alarms provide only 500ma current capacity for their pulsed
outputs (unless the manual explicitly sez that the alarm has built-in
relays  for the pulsed output) . In order for it to operate the high
current actuators, one needs to install two relays as a push-pull pair.

There are 2- and 5-wire actuators on the market. You can use either one,
but with a 5-wire one you only need 2-wires, blue & green. When I do a
power door lock install in a non-power car (lesser Japanese makes etc.)
I always use two 5-wire actuators for the front and two 2-wire actuators
for the rear. The 5-wire unit has a built-in switch, that senses a
closed/open condition, hence commanding the rest of the 5- and 2-wire
units to close (or open). When installed in a front door, it allows to
open/close all doors not only with a push of a button, but also by
physically moving the shaft of the actuator (i.e. moving the locking
knob). You don't need it with the Audi. 

-- 
Igor Kessel
'89 200TQ -- 18psi (TAP)
'98 A4TQ
Philadelphia, PA
USA