Page 1 of 4 1234 LastLast
Results 1 to 10 of 34

Thread: FB3 Power

  1. #1
    Join Date
    Aug 2006
    Location
    North West England
    Posts
    1,148

    Default FB3 Power

    I'm sure I saw a post somewhere about being able to power the FB3 via a second USB lead, but for the life of me I cannot find it

    Was I dreaming?

    Jim

  2. #2
    Join Date
    Feb 2007
    Location
    Herts, UK
    Posts
    1,254

    Default

    On the older FB3's you can power the FB3 over the USB just by adding a jumper/bridge on the board.
    Best to find out fom Bill if you can do the same with your newer FB tho...

  3. #3
    Join Date
    May 2007
    Location
    Milwaukee WI
    Posts
    1,355

    Default

    Hmm this would have been good to know about a while ago.... but then again the extra 5v supply I have is helping out elsewhere.

  4. #4
    Join Date
    Feb 2008
    Location
    East Sussex, England
    Posts
    5,248

    Default

    Hi Jim

    I'm wondering why you want to use a second USB lead to provide power when the single one should cover it?

    I did think about going this route myself but have plumbed for the 'wall wart' route as it's easy to implement, and easy to fix/replace if it ever goes wrong. Given the variety of USB ports out there I'm not sure i trust them to provide the power.

    On a similar vein, would a 300mA supply do it, or should I go for 500mA? Bill did say that it was under 100mA when running on card and about 300mA on USB, so would the 500 give some safety margin?

  5. #5
    Join Date
    Jul 2007
    Location
    Knoxville, TN, USA
    Posts
    3,154

    Default

    I used my laptop's USB ports as the power source for my FB3 while I was traveling with Unce Sam last summer - I just wired in a second USB cable and plug to the power input terminals on the FB3.

    I never had any problems with the arrangement, but I was also careful to make sure I didn't have any other USB-powered devices plugged into the laptop at the same time (I didn't want to put too much load on the laptop's 5 volt supply on the USB bus). If you want to go this route but are concerned about overloading your computer's power supply, using a USB hub with its own power supply (instead of powering directly from the computer's USB ports) will probably work fine.

    RR
    RR

    Metrologic HeNe 3.3mw Modulated laser, 2 Radio Shack motors, and a broken mirror.
    1979.
    Sweet.....

  6. #6
    Join Date
    Aug 2006
    Location
    North West England
    Posts
    1,148

    Default

    Running LiveQ and without the projector plugged in its drawing just over 300mA according to my bench PSU.
    I'd go for the 500mA supply.

    Jim

  7. #7
    Join Date
    Apr 2006
    Location
    Orlando, FL - USA
    Posts
    1,770

    Default

    Hi all,

    You can "bus power" a FB3 pretty easily. On the newer ones, with USB "B" connector on the daughter board, there are two gold through-hole pads. They are the only two gold through-hole pads. If you put a wire there, it will allow you to bus-power the FB3.

    Once enumarated, a USB device may draw up to 500mA (as long as it has been given permission to do so by the driver and PC root hub).

    In any event there is one thing to keep in mind. If you bus-power the FB3, we HIGHLY recommend that you simply remove the other power wires from it. Otherwise you will have a kind of collision between some external power supply, and the PC's USB power.

    Bill

  8. #8
    Join Date
    Feb 2008
    Location
    East Sussex, England
    Posts
    5,248

    Default

    Bill, not quite sure what you mean by 'through-hole pad'

    Can you point out which bit in the photo if its visible please?

    Are they the 2 very small holes running vertically, just to the left of the horizontal silver oval thing on the usb daughter board? (do you love my technical descriptions?)
    Attached Thumbnails Attached Thumbnails DSC00132.JPG  


  9. #9
    Join Date
    Jan 2007
    Location
    Sheepsville, Wales, UK
    Posts
    3,406

    Default

    Norty
    I have marked a pair of pads from your pic - they are gold and are through hole plated as Bill said there are only 2 pads like this I would take it that these should be the ones you want. May be worth testing them with a meter (continuity) to be certain
    Rob
    Attached Thumbnails Attached Thumbnails DSC00132.JPG  

    If you need to ask the question 'whats so good about a laser' - you won't understand the answer.
    -----------------------------------------------------------------------------------------------
    Laserists do it by the nanometre.

    Stanwax Laser is a Corporate Member of Ilda

    Stanwax Laser main distributor of First Contact in UK - like us on Facebook http://www.facebook.com/FirstContactPolymerCleaner
    www.photoniccleaning.co.uk

  10. #10
    Join Date
    Apr 2006
    Location
    Orlando, FL - USA
    Posts
    1,770

    Default

    Yep, those are the holes. Just MAKE SURE you don't connect the FB3 to the normal power supply when this wire is in place.

    Also, this can be done on old FB3 as well, but the place where you put the jumper is not as obvious...

    Bill

Posting Permissions

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