[sdiy] MIDI processor - power from midi in?

[Harry Bissell Jr]

Standard MIDI has only two pins used, they are a
current loop that supplies an LED in an optocoupler at
the receive end.

In a stand alone box (like the Anatek which is what
I think you are mentioning)... you could directly
couple the input, steal power from it, then send that
to another isolated receiver.

Some other interfaces have some MIDI sync pulses for
drum machines etc... but they are non standard.

The Anateks would sometimes 'not' be able to steal
enough power and had auxilliary supplies if needed.

H^) harry

--- nN AAt     e     e <timexheater at comcast.net>
wrote:

> doesn't midi have a +5v signal running through one
> of the pins? i remember
> some simple midi utilities  [arpeggiator, chord
> memory, filter... all
> probably pic based] that would run off of the midi
> line as long as you had
> steady power for it and didn't chain them
> together... shouldn't any keyboard
> or midi interface be outputting enough to power
> something?
> 
> - nathan
> 
> > If you are receiving multiple MIDI sources you
> might
> > combine the power, but it would be very complex,
> or it
> > would tie all the MIDI inputs together... ground
> loop
> > hell, maybe kaboom.
> >
> > For very low power, yes its possible.
> 
>