Need Help with a Daytime driving lights schematic?

[scottyb]

Okay, I’ve decided that I want Daytime Driving lights for my Elise. Also I don’t want to keep pressing the button on and off each time I get in and out of the car. So I came up with a circuit that should create a momentary pulse to turn the side lights on and then turn the side lights off. I also didn’t want to disable the light switch on the dash.


I kept the circuit analogue. It is powered by the car battery, but has a switching transistor flipping the flow of current to the circuit that would be connected to the accessory position of the ignition.

Now it’s been 18 years since I’ve done circuits so if some of you EE’s or CE’s could give a little critique it would be greatly appreciated.

[rob13572468]

it looks like there might be a couple things wrong with the circuit; im pretty sure that it can be doen without needing 3 relays. at any rate my understanding is that you want to create a pulse to turn the lights on with ignition and then off when the ignition is turned off...

the easiest way to accomplish this is to purchase a ready made module DEI part number 452T... normally for power locks, it monitors a line and pulses one output when it goes high and a second when it goes low. you would simply attach both outputs to the light switch and the monitored line to ignition.

alternatively, you can simply add a relay that feeds 12 volts to the lights circuit itself rather than the light switch...

[scottyb]

Originally Posted by rob13572468

it looks like there might be a couple things wrong with the circuit; im pretty sure that it can be doen without needing 3 relays. at any rate my understanding is that you want to create a pulse to turn the lights on with ignition and then off when the ignition is turned off...

Thanks Rob! I new there had to be a simpler way, but its been too many years since of done this kind of stuff.

I'm not sure that a +12 will turn the lights on, and I didn't want to add any voltage to the Elise's (Multi Function Light/Ignition/101 other things) Circuit because I have a fear that something might get burnt out or blown. So I figured by just creating a momentary short between the light switches wires, I would simply be simulating what happens when you press on the switch. That is why I went with relays as opposed to transistors.

Any idea where I can purchase this relay?

[TTP]

try here http://partsexpress.com/

[scottyb]

Originally Posted by TTP

try here http://partsexpress.com/

Couldn't find it.

[AaronLV]

http://www.partsexpress.com/webpage....ectGroup_ID=31