Re: Subsituting USB power for Battery?

From: Randa (no-mail_at_randa.randa)
Date: 12/08/04

  • Next message: Calum MacLean: "Calculating frequencies based on cycle counts" 
    Date: Wed, 08 Dec 2004 07:01:59 GMT

    h1dd3n_h4m$73r@salmahayeksknockers.edu wrote:
    > I've got a battery powered peripheral (FM Transmitter) that I'd
    like
    > to power from USB.
    >
    > I know that USB puts out 5v, and that a "Double A" batter puts
    out
    > 1.2 v, and assume that two would put out the same.
    >
    > Can anyone point me in the right direction to make my little
    project?
    > I have a soldering gun, and can use it, but need an idea of what
    kind
    > of parts to put in between.
    >
    > Also, is there any danger that dicking around with a USB cable
    like
    > this could cause corruption elsewhere in the USB bus?

    You can overload the current capabilities of the USB bus on your
    motherboard and potentialy damage your board. One of the things
    you should determine before you get too excited is what the
    current requirements are for the FM transmitter. Then add in your
    other USB devices and see what your motherboard is willing to
    support.

    Now you know why there are active (powered) and passive(USB cable
    powered) USB external hubs.

  • Next message: Calum MacLean: "Calculating frequencies based on cycle counts"