Antwort: Re: [sdiy] midi to mosfet - question

[Christian.Bergmiller at daimlerchrysler.com]

i thougt i could use the four unused lines of the 36 pin connector for the
common ground..
no good idea ?
The number of switched on notes could be limited by software to maybe  8 or
ten.
This would give 5 ampere over four contacs.

Christian



                                                                                                                                             
                      asfi at eol.ca                                                                                                            
                      Gesendet von:                  An:      synth-diy at dropmix.xs4all.nl                                                    
                      owner-synth-diy at dropmi         Kopie:                                                                                  
                      x.xs4all.nl                    Thema:   Re: [sdiy] midi to mosfet - question                                           
                                                                                                                                             
                                                                                                                                             
                      04.02.2004 09:02                                                                                                       
                                                                                                                                             
                                                                                                                                             




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