[GreenKeys] Current limiting

[Michael O'Day]

 OK, then based on what both Jeff and RiceGuy said, I
 will have to build a 120+ power supply to adequately
 power the 19's selector magnet. Should be within my
 skill set, but to key it with a PK232 I'll need to
 make an adapter board. Has anyone had experience
 using
 an opto-isolater chip as an interface? We used to
 have
 dot-matrix printers that replaced the model 33 SPO
 printers that had a current loop interface that fed
 the serial input via an on board isolator chip.
 
 Mike - N9ODM
> 
> --- Jeffrey D Angus <jangus at socal.rr.com> wrote:
> 
> > Michael O'Day wrote:
> > > Does that mean the 15 requires a higher voltage
> > that
> > > the 33? I recently aquired a 15, do I need to
> > build a
> > > HV (120+) supply for it, or can I run it on one
> of
> > > those Black Box RS232/Current Loop adaptors?
> > The Black Box doesn't seem to like to be used in
> the
> > passive mode
> > (i.e. external power supply) at 120 VDC. The
> output
> > device seems
> > to self conduct and stay in the "on" mode.
> > 
> > Nor does the Black Box have enough "oomph" to
> drive
> > the selector
> > magnet properly when used in the "active" mode.
> > 
> > Good thing I bought three of them, I think I've
> > killed the first two
> > trying to get them to work properly with the
> Lorenz
> > LO 15 C.
> > (A clone of the Teletype Corp Model 15.)
> > 
> > My next strategy is to go through the subscriber
> box
> > of the Lorenz
> > (which has a polar relay) and see if I can key
> that
> > line properly and
> > not kill my remaining Black Box.
> > 
> > Jeff-1.0
> > wa6fwi
> > 
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> > 
> 
> 
> 
>       
>