Flashing alarm LED

Roger20

Roger20

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Hymer Exsis T - 588
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Can any of you clever guys out there help please.

I fitted a flashing 12v LED to the rear of the van, with the intention of it being linked into the alarm. For reasons which would need another thread this link hasn't happened. I have easy access to an ignition controlled supply from the vehicle side as well as a permanent supply from the leisure side. With a bit more trouble I can also get a permanent feed from the vehicle battery using the radio memory code supply. Is there is any way in which the LED could be switched on when the key switches off the ignition?
 
Roger20 said:
Can any of you clever guys out there help please.

I fitted a flashing 12v LED to the rear of the van, with the intention of it being linked into the alarm. For reasons which would need another thread this link hasn't happened. I have easy access to an ignition controlled supply from the vehicle side as well as a permanent supply from the leisure side. With a bit more trouble I can also get a permanent feed from the vehicle battery using the radio memory code supply. Is there is any way in which the LED could be switched on when the key switches off the ignition?
Click to expand...

With the amount of power they use (typically 10ma) you can leave it on all the time.
 
From the sound of it, you need to somehow feed the Led from the alarm unit itself, so that it is fed from the 12 volt supply only when the alarm is armed. This should not be too difficult if you have a wiring diagram for the alarm, as most car alarms have at least one flashing LED inside the car on the dashboard or rear view mirror mounted. Your other suggested method, I think, would mean that the led would be activated every time you turn off the ignition, which is to me would maybe act as a visual deterrent , but I would try linking to the alarm so that it only becomes active and flashes when armed.
However a simple spdt relay in series with the LED connected to any permanent 12 volt supply will feed the Led. In other words when the ignition circuit is on (live) it breaks the normally closed relay which in turn stops the 12 volt feed to the LED. 12 volt feed from live ignition operates the relay coil, I wish I could draw it out for you, but hope you get the gist of it.
All the best
Les
@eddievanbitz is now laughing his head off while reading this,as he knows I have a Growler system with more flashing Blue LED's than Blackpool Tower:D2 Wheres me sunglasses:eek:
 
A small relay that switches the LED off when ignition voltage is applied across it.

https://cpc.farnell.com/unbranded/h...tOIORJ_mCn1_ngV4jY1CNG1ZsPHbQayIaAr13EALw_wcB

handy.jpg

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Roger20 said:
Is there is any way in which the LED could be switched on when the key switches off the ignition?
Click to expand...
In the old days you would just wire it through the alternator field coil (ignition light on dash .. )
But you could use a 5 terminal relay that holds a contact open when engine is runni g but switches to a supply when you turn engine off..
Andy.
 
That's great guys - thanks. A normally closed relay - so simple then. Tapping into the alarm isn't an option whilst under warranty (and bearing in mind about the need for another post!!!)

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Why not ask the alarm installers to add a couple in for you?
 

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