Can you turn the dimming effect off on internal lights?

Discussion in 'Gen 4 Prius Accessories and Modifications' started by The Professor, Feb 6, 2019.

  1. The Professor

    The Professor Active Member

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    May seem like a bizarre question... Is there any way to turn the dimming effect off, so the interior lights just turn on/off instantly, rather than dimming up/down when they are switched on/off?

    I replaced my interior lights with LEDs. When the interior lights turn on (e.g. when the key fob is near the outside of the car) or off (e.g. 30 seconds after getting in the car), a dimming effect is used. This is achieved via PWM (turning the power supply on and off very fast). This is fine for a filament bulb, as they stay hot between the pulses so you don't notice any flickering. However, for LEDs this makes them noticeably flicker near the dim end of the effect.

    In case anyone wants some more details... the light with the issue is the rear dome light. I fitted a nice LED panel light in there that you can set remotely to any RGB colour or brightness. It works well, and the kids love having a very low ambient blue light on at night (I agree it looks cool and matches the button illumination, etc)... other than the fact that you hardware reset the light by turning it on and off very fast 6 times. Unfortunately, the PWM dimming effect often resets it. I can go down the route of making my own PWM low pass filter, using a resistor + capacitor, and maybe a diode to protect from reverse current, but I was hoping for something easier.
     
  2. kithmo

    kithmo Couch Potato

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    I can't see any way of disabling the gradual dimming without turning the, "lights on as you approach" option off altogether. You'll probably need to swap out to dimmable LEDs.
     
  3. priusG

    priusG Junior Member

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    maybe you used low priced LEDs?
     
  4. The Professor

    The Professor Active Member

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    The best LEDs in the world are still going to turn on and off if the power supply turns on and off. It's simply down to the fact that the PWM frequency Toyota use is meant for incandescent bulbs that react very slowly, compared to LEDs which react instantly. You can work around it with things like low pass filters, but these are bulky; too bulky to fit in an LED festoon package for example, given the capacitor required alone would be several times bigger.
     
  5. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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  6. The Professor

    The Professor Active Member

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