Results 1 to 3 of 3
  1. #1
    mtbr member
    Reputation:
    Join Date
    Jul 2008
    Posts
    124

    Dimmer Switch and P7

    I have a bedroom light I am building with a P7 LED powered by a 3.6v 3A DC converter and a 2.8A single mode driver. Right now it's on or off but I'd like to swap the switch for a dimmer if I can.

    Any suggestions?

    Thanks,

    David

  2. #2
    mtbr member
    Reputation: mattthemuppet's Avatar
    Join Date
    Jul 2004
    Posts
    2,301
    unfortunately, you can't dim LEDs like you can incandescents. You can drop the voltage a bit with a rheostat, which will dim the light (similar to a discharging battery) but under a certain voltage (3V for a P7?) the LED will just stop functioning. I see it with my LED dome light in the car - it used to dim all the way down to nothing, now it dims a bit then switches off.

    The best way to control current with tiny steps between full power and next to nothing is to get a custom programmed driver that ramps the light up and down as long as you hold a switch down. I'm not 100% certain how they work, but I know DrJones and JonnyC on BLF program drivers so they'd be able to help you. It would probably be cheaper than fitting some kind of rheostat too

  3. #3
    mtbr member
    Reputation:
    Join Date
    May 2010
    Posts
    333
    Either buy one of the dimmable led 240 or 110 direct replacements and use as is or break it for parts?

    Edit:

    Interesting read here - Samsung LED light bulb teardown includes objective dimming numbers | EDN
    Last edited by MrLee; 09-19-2012 at 03:12 AM.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •