Bill wrote in MMD 040708:


>> I would not contemplate operating 240V solenoids directly:
>> it is far too dangerous if outside.


You might try operating the solenoids on 48 VDC rather than the 240 VAC.
This will reduce your shock hazard and you can use standard transistors
driven from a MIDI interface board that would provide 0.5 ampere
output.  I would suspect that the current drawn by the solenoids
running on 48 VDC might be as high as 2 amps or more.  Measure the
resistance of the coil with an ohm meter and use ohms law to get the
current.

You will have to add diodes across the solenoid coils to suppress the
kick back voltage when the power transistor is turned off.  Good Luck.

Pete Knobloch