[sdiy] midi to mosfet - question

[Colin Hinz]

On Wed, 4 Feb 2004 Christian.Bergmiller at daimlerchrysler.com wrote:

> Hi,
>
> i'm currently building a midi to mosfet "open drain" 32 channel interface.
> It uses the AT90S2313  uC, 4* 4094 shift registers for I/O extension and
> 32* 2SK1904 mosfets on the outputs.
> On breadboad it worked ok so i am prototyping it on some kind of
> stripboard.
>
> I want to put the whole thing in a box and connect it to the world via 36
> pin centronic connector.
> My question is if swirtching 32* 24V Solenoids at 500ma connected via
> 3meters of Cable (just an example)
> will produce hf noise (or whatever :-) that would couple into equipment
> used around it ??
> is shielded Cabel enough protection. do i have to use some kind of "slew
> rate limiting" ?
> Or should i put this interface just as close as possible to the solenoids
> has to power ?

The "common" side of the solenoids isn't connected through the Centronics
connector, correct? (I *do* feel compelled to ask these sorts of things,
please forgive me.)

How many outputs will be switching simultaneously?

- Colin Hinz
  Toronto, Canada