DEI 528t Triggers?

Hi,

I have a dei 528T pulse timer and would like to know more about how to trigger it to connect a circuit with my LED footwell lights on to turn on when the alkarm is disarmed for 90secs.

My alarm has a constant negative output when armed which goes to zero when disarmed. It also has an unused immobiliser circuit that can break a connection up to 10amps.

Does the 528T have a facilty to be triggered by a constant source which goes to zero?

Or can it be triggered by a source that goes from zero to a constant ground (using the immobiliser wires to disconnect >>> connect a wire going to a ground source)

Also what happens after triggering does the circuit connect for the set timed duration and then disconnects regardless of a still present trigger input which is still constant?

Thanks,
Mo

you can use the unlock wire from the alarm to pulse the 528T

Swamprat323 is right, use the unlock pulse from your alarm to trigger the 528t.  This relay works like a normal relay, meaning it only needs a momentary pulse to trigger, but will stay latched for the amount of time it is set up for.  You'll just have to adjust the set screw to increase the time.

Hi Guys,

That's the problem my alarm does not have any onboard locking controls to pulse the 528T all it has is a constant negative out when armed. Also the unused immobiliser circuit interrupt.

Any ideas???

What is the make/model of your system? There are not many that do not have door lock outputs.

Twelvoltz wrote:

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What is the make/model of your system? There are not many that do not have door lock outputs.

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https://img51.imageshack.us/img51/7470/alarmdiagram1ao.gif

Click the link then click on image to enlarge.

Here's the instructions from the alarm, which may help clarify the system.
Thanks, Mo

According to the diagram there is a BROWN / white that is remote control activated (presumably a channel 2 output). You could use this wire to activate the pulse timer anytime you want the lights to come on.

Hi,

The BROWN / white is attached to the ultrasonic sensors (-ve power supply).

The keyfob only has 2 buttons:

Button 1: arm/disarm or arm press again quickly exclude interior ultrasonic sensors

Button 2: purely as a panic button (not programmable)

Thanks,
Mo

just use the the parking output then. but this will make it coem on also when armed.

That would set off the alarm when armed, due to a negative being supplied to the dome light.

How about if I use the 'cut-off' circuit on the alarm to interrupt a ground wire connected to the BLACK/ white stripe trigger wire on the DEI 528T.

This would, when the alarm is armed interrupt a constant ground going to the 528T trigger wire and when disarmed it would reconnect the constant ground to the trigger wire.

My theory is that when disarmed it would illuminate my door step lights for the set duration and when armed it would take away the trigger to the 528T so when disarmed again it would trigger he 528T again.

So could someone confirm that the 528T can be utilised with a constant rather than a pulse negative source???

Thanks

mmh1] wrote:

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br>How about if I use the 'cut-off' circuit on the alarm to interrupt a ground wire connected to the BLACK/ white stripe trigger wire on the DEI 528T.

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That would work, however...it will also leave a relay energized the entire time your alarm is armed, causing the vehicle battery to drain over time.

Twelvoltz wrote:

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That would work, however...it will also leave a relay energized the entire time your alarm is armed, causing the vehicle battery to drain over time.

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Would this still be the case as the 'cut off' circuit is built into the alarm brain and uses two wires coming out of the brain to interrupt a circuit max. 10amp.

ie. choose a circuit to interrupt then cut the wire connect one end to the GREEN/ black from alarm and connect the other to the other GREEN/ black from the alarm.

Or did you mean the dei 528T will remain energized? As I will be using the normally open brown wire only to power my step lights...which will be activated only when disarmed for the time delay of 45sec (enough to light the way into the vhicle)

Thanks, Mo

No, what is happening is the brain of the system is providing a ground when armed only, the relay that controls the starter kill will only be energized when there is either ignition or starter voltage (depending on the internal wiring) coming into the brain and in turn activating the relay. This is the same as if you were wiring an external starter kill relay.

On the alarm instructions it says:

GREEN/ BLACK
GREEN/ BLACK

"These wires carry out electrical engine cut-off. Cut the positive or negative wire going from the igntition key to the fuel pump, electrovalve, starter motor etc. (max. 10A)"

Just wondering if that sheds anymore light???

Thanks, Mo

I may not be wording it correctly, but maybe this will help you understand. Here is a diagram showing how to wire a starter kill relay. If you look at it, the relay is only energized when there is power to the ignition circuit, otherwise it is essentially off until it is needed. You can not start the vehicle without energy to the ignition circuit, and in this case, if the alarm is armed and there is energy applied to the ignition circuit, the starter is disabled. This is probably how it is wired internally, so that circuit does not draw energy unless there is power to the ignition circuit.

Hope this clears it up.

I see what you mean...thank for your advice and patience :)

I thought it would just act as an arbitrary electronic circuit interrupt, but now you mention it might be dependent on the ignition being activated to initiate the iterrupt it gives me food for more thought.

I think I'll have to experiment and meter the cables while armed and ignition activated to see.

So annoying, why can't simple alarms come with a dome light supervision wire? would've prevented all this headache.

Thanks, Mo

I just took a look at the diagram again, and realized that there is no ignition input to that system. Your starter kill circuit is probably only energized while the system is going off. Take a look into it and keep us posted.