When I install my knocklink into my car I am going to remotely mount the LED’s in the instrument binnacle.
What I am thinking of doing is taking a spur off the positive feed to the red (danger) led and running it through a relay to a buzzer as an extra warning. Is this a good idea, if so is it feasable?

 

will have to be a very small relay... I would drive it with a transistor really... Also dont forget to use a diode for back emf supression.

David

 

Cheers for the reply Dave, any chance of a translation into language a mechanicaly minded muppet can understand.
Mike.

 

yeah, dont do it unless you are sure you know what you are doing..

David

 

I thought I did know what I was doing, ie find out what voltage is sent to the relevent LED, go to maplin & get a relay that can be operated by that voltage and wire up as above.
what is back emf supression ?
thanks, Mike.

 

You might also look into what current the LED requires. You will find that it is miniscule compared to driving the electromagnet in a relay. Not a good idea. To be honest, you are more likely to find a piezo electric buzzer that could be driven directly from the led output than a relay to isolate it... but thats also a tall order for an led driver.

 

Ok, thanks for the replies, I think I will shelve the idea for now then. Mike