[sdiy] usb power?

[HL-SDK Synths]

I've gone by the rule of thumb that 1 plain LED (at standard
brightness) will take about 15mA. Now you have an assy that uses
higher voltage. Hook it up to 5V w/ an ammeter in series and adjust
brightness, or just read off the number if it is as bright as you
would like it to be.

On Sun, Mar 22, 2009 at 2:25 PM, db <dbarton at pacbell.net> wrote:
>
>> From your numbers of 25 LEDs and 4.5V, I can only guess you want some
>> white LEDs and intend to suck the maximum of 500mA.  Is that correct?
>> You can probably get away with that ... mostly.  If you are sucking
>
>
> I don't know how much current these lights use, as they are just small 25
> led lights that come all assembled, so I have no specs.
> Does anyone know an approximation of how much current I might be using with
> the 25?
>
> Is it easy to measure? Can I simply connect a DMM in series an get a useful
> reading?
>
> If I need to, I'll use an external supply,. but that complicates things a
> bit for this app.
> I have the laptop controlling the LEDs on/off, as well as powering them.
>
>
> dennis.barton:skylab2000[socal]
>
>
>
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