[GreenKeys] ASR33

[Geo. Hutchison]

Hello all - - -

As I recall the way the 33/35 selector magnet drivers are supposed to 
work is that the line current into the driver is always  20 ma unless it 
has been set-up for 60 ma.

The magnet current initially should slam the magnet on with about 500 
ma, and then as the current builds up the magnet current is tapered down 
to a much lower value to hold it in place. This has the advantage of 
when the magnet is released as the signal goes to space, the flyback 
voltage created across the magnet as the field collapses is much lower 
due to the decreased intensity of the magnetic field.

The circuit is running in an analog fashion. If your holding current is 
450 to 500 ma then you have the answer...

Been a long time since I worked on 32/33/35 stuff. Haven't missed it at all.

W7TTY