Automatic Headlights

[jharris]

Hey Guys,

A lot of our customers have been asking for a way to have their Cobra headlights turn on automatically at dusk. We've been recommending a few different ways to do this with our Infinitywire system for years now. We finally got around to creating a schematic for this. Using our Infinitywire 20-circuit system and about $10 of parts from Amazon, you can easily get this function in your car.

The part from Amazon is a photoelectric controller. It is a small PCB with a relay and some simple circuitry. There is a harness coming off of it with a photo cell that you would mount on your dash facing up. It has a simple potentiometer on it to adjust its sensitivity. Here's the link (http://www.amazon.com/Photoelectric-Switch-Sensor-Module-50mmx25mm/dp/B00BLZ93T2/ref=cm_cd_al_qh_dp_i).

From there, you connect the output from this photoelectric controller to the headlight input on our MASTERCELL. You can either have this stand-alone as the only switch for your headlights or you can wire it in parallel to your headlight switch. That way, either the switch or the photoelectric sensor will turn on the headlights.

Here's a quick schematic.

36189

You can read more about how to wire this into your MASTERCELL by clicking this link. (http://infinitybox.com/2014/12/02/automatic-headlights/)
Let us know if you have questions.

Jay

[DaleG]

Will certainly go Infinity with the next build, but in the mean time, does anyone know how to wire in that photo-electric controller to the MK4 Complete kit Ron Francis harness/and supplied switch? A schematic/diagram would be great. I just love gadgetry; probably should take a hiatus from the forums so I can finish the car.

[jceckard]

Be sure to read some of the reviews/comments about the module on Amazon's page. This module in particular has a hysteresis issue and the relay can chatter (really bad). It's a quick fix though. Solder a resistor (10k should do) on the feedback of the opamp. There is one review with several comments that detail the modification.

[DaleG]

Thanks for the heads-up. I'll see if I can Google how to do it.

[Scud67]

Dale - you can just have the photo cell trip a relay to control the lights - very simple.

[DaleG]

Scud67, could you elaborate. I've found a few kits online, but have not dug too deep into them. I think I will just stay with the supplied switch for now and get back to the important stuff so I can get on the road; I keep getting side-tracked by gadgets:cool:.

[2bking]

I purchased this device several months ago with the intent of using it to dim the dash lights at dark. When I wired the gauges, I found this function was built into the power supply that controlled the LEDs in the gauges.

The Infinity Wire System doesn't require ignition "on" for headlight operation so some thought needs to be put into the wiring of this device to keep the headlight from turning on when the car is parked. The instructions in the link don't seem to address this problem.

[DaleG]

Boy, wouldn't that be a surprise, walking out into the dark garage and finding your lights on.

[Scud67]

That's why you use a relay.... you can tie the trigger of the relay to the ignition switch (the feed side) and have the ground side tied to the photo cell (through the photo cell to ground to trigger the relay). Supply 12v power to the controlled circuit on the relay and the output side goes to the headlights. Not hard. I don't have a diagram but I can draw one out later and post it. I am going to use a relay on a switch to control my high/ low beams - very similar set up on the relay for control.

[Scud67]

Hi Dale, You don't really need a "kit".... you can buy relays and relay harnesses at your local auto parts store and wire everything up yourself (and save $$).

[DaleG]

Thanks, Scud. Makes it easy. I'm using relays on HI/Low beams, and the wipers. Similar.

[jharris]

Guys,

Regarding the lights turning on in a dark garage, that is why the schematic shows wiring the photoelectric module power from the ignition output on the front POWERCELL. The twilight function will only work when the ignition is on.

Jay