MIDIpar
   
   Conventional System configuration with the 
common to the magnets or solenoids, POSITIVE
Basic boards use ULN2803a IC's that are rated
at 500 mA per gate, 8 gates per IC. Voltage
   up to 40v DC. 
   If more than 3 outputs are on at one time, the 
   current is lower. 
Boards are available from 8 notes to 128 notes
in a variety of configurations.