Questions Regarding DRL/High Beam Operation
 

Before anyone says it, yes I have searched.

Part 1
Our high beams and our DRL both share the same bulb. We know that the DRL works by reducing the amount of power supplied to the bulb. This means that they are running at different wattages, but are the voltages the same? Why am I asking this exactly? It's pretty simple really. Like many others, I have LED DRL bulbs. Unlike regular filament bulbs, LED's require a certain amount of voltage to become lit. Their primary source of power is current, but they can be affected by voltage. If the voltage changes, there would be a noticeable change in the light output of the LED bulbs. (If I understand correctly, constant current drivers will operate at different voltages. Therefore, the current would remain the same, but the wattage would change.) However they do not change in brightness, which makes me believe that the car simply changes amount of available current. (A decently designed LED circuit uses constant current drivers, so this would have no affect on them if the voltage remained the same.)

So pretty much: Do the high beams operate at the same voltage as the DRL?

Part 2
We know that the dealership can disable the DRL. The FR-S uses a 3-position switch to control the lighting. Can they configure what turns on at each switch position?

Factory Settings:
Position 0 = DRL
Position 1 = DRL and Running Lights
Position 2 = Driving Lights and Running Lights

I would like:
Position 0 =
Position 1 =
Position 2 =



Why don't I just go test it? I'm putting something together, but will be away for another month. I just want to make sure everything is in line, or weigh the various options.

Kev

I'm not sure in have the perfect answer to this, but LEDS are intended to be either on or off, not in a middle state. To control brightness Pulse width modulation (PWM) is used. LEDs if under powered will fade a little, but it damages them to run them that way. much like lightbulbs in AC environments, to control LED brightness you give them off on cycles at various work loads to control them. Incidentally this is how electric motors are controlled as well.
I think no matter what the LEDs are fully powered here, otherwise they would have dramatically reduced life spans.


If Im bored later Ill crack out my multimeter and read the socket voltage for you under drl and high beam, but I expect they will be the same, just less current.

We're both on the same page with the LED explanation, just two different directions. I tried to not get into the LED aspect though. I just wanted to show that as possible supporting evidence to what I think about the voltage being the same. Now if there was a constant voltage (step down) regulator inside the LED bulbs, the that would completely debunk my thought process.

Thanks by the way

Can anyone chime in on Part 2?

Actually, I need to rethink that setup.

that IDK... you could buy the Toyota Team Stream thingy and then you will have all the options they do.