voltage trigger

I have a 2011 Hyundai Sonata. Right now the DRL and the high beam are the same bulb. When in DRL mode, the bulb get like 3 volts. When the headlights are on, the bulb goes off unless you hit the high beams, then they get 12+ volts. I am looking at getting a set of headlights with an LED in them, sorta like the Audi, and would like to use those for the DRL. What I need is a way to power the LED when in DRL mode, and have the bulb off, and be able to use the high beam without the LED's coming on. I would think a tR7 would be the route to go, but am not sure.

When you put the High beams on, do the low beam lamps remain lit?

Why don't you just power them with an ignition source? Is there ever a time your drls or head lights won't be on?Kevin Pierson

Power your LEDs from your switched ignition power source, with the returns connected to the high beam filaments. The resistance of the high beams will be able to act as a virtual ground because of the low draw of the LEDs. When your high beams come on, the LEDs will turn off. If you need to turn the LEDs off whenever either your low beams or high beams are on, then just use a relay with the coil connections between the high and low beam, and the LEDs powered through the normally closed contacts. Whenever either of your lights are on, the relay will be energized, turning the LEDs off. Use a standard unpolarized relay so it can be energized in either direction.

dualsport wrote: Power your LEDs from your switched ignition power source, with the returns connected to the high beam filaments. The resistance of the high beams will be able to act as a virtual ground because of the low draw of the LEDs. When your high beams come on, the LEDs will turn off. If you need to turn the LEDs off whenever either your low beams or high beams are on, then just use a relay with the coil connections between the high and low beam, and the LEDs powered through the normally closed contacts. Whenever either of your lights are on, the relay will be energized, turning the LEDs off. Use a standard unpolarized relay so it can be energized in either direction.

I think I understand, but can you draw a diagram?