I did some SCR stuff with hockey puck SCR's to
catch reverse EMF from a can crusher by wiring
them as diodes. I was able to pass 12.5kA in
this way. Eventually blew at 15kA but my voltage
sharing in the stack was not well thought out.
Peak allowable current for a similar puck is
150A into the gate. I never got to measure it
but gate current will rise progressively with
applied voltage until the SCR conducts in this
setup and will tend to force rapid conduction.
Certainly on the CRO the turn on in a diode
setup was very rapid at least at low currents
and seemingly much faster than might be expected
from a big SCR and I seem to recall seeing
little overshoot even at microsecond timeframes.
http://tesladownunder.com/CancrusherSCR.JPG
http://tesladownunder.com/CancrushSCRbank.jpg
http://tesladownunder.com/CanCrushing.htm#Can%20crusher%202
Peter
Original poster: Finn Hammer <f-h@xxxx>
...
Of course I was worried that a SCR would not be
able to perform the task, but since the SIDAC´s
shouldn`t either (too high dI/dT) I gave it a go.
...
I had selected the IR 25TTS12 1200V/16A SCR for
the job, and noted that it could be triggered by
46mA @ 2Volts on the gate, so I figured that if a
gate transformer cold be made to deliver 2 volts
into a 23ohm rsistor, I`d be on the right track.
...
Cheers, Finn Hammer