In previous postings I have described a MIDI-controlled solenoid
operated harpsichord.  I have run into a problem and am looking for
some advice.  The solenoids (from QRS) draw about one ampere.  They are
controlled by one of John Wale's MIDI units through a homemade driver
board.

Recently one of the solenoids burnt out and in the process went short
circuit.  This in turn caused a huge current in the driver which
subsequently charred and sent a plume of smoke into the air.

I know that the commercial solenoid pianos have protection circuits.
Are there any suggestions on how to prevent this from occurring again?
I guess I could put a fuse in-line with each solenoid but I would hope
there is a better solution.

Regards to all
Phil Dayson
Vancouver Canada