In MMD 020119 Tony Decap states:

> Because of the resistance, a part of the energy is not converted
> into magnetic force, but into heat.  And if the coil heats up, the
> resistance increases (another nasty law of nature).  So to keep the
> same magnetic force, one must increase the input power, with more heat
> as a result.  This will end in a coil burnout if you are not careful.

I'm not an electrical expert, only an organ builder, but doesn't
"reactive resistance" come into this equation?  When the magnetic field
surrounding a coil changes, as happens when a solenoid is switched on,
a current flow is induced in that coil which _opposes_ the current flow
which switched on the coil in the first place.  Thus, the initial power
output of the coil is less than its maximum -- just when you want it
for actuating a piano hammer.  Perhaps someone with more technical
know-how electrically than me could confirm this.

Also, when considering electric action in a church organ, I always try
to utilize the existing wind supply available from the blower for
secondary pneumatics, which is far cheaper to produce than electrical
power from an expensive transformer-rectifier unit.  Using electric
valves only for the primary action may be more costly in manufacture
but less costly in use.

Regards,
John Page

 [ The effect of the static coil impedance that you mention, and also
 [ the complicated effect of the armature moving within the magnetic
 [ field, is neatly avoided if power from a controlled current switch
 [ is applied instead of a using a controlled voltage switch.  The
 [ extra circuit compenents needed add very little cost.  -- Robbie