The reverse voltage (Back EMF) is controlled by the Back EMF diode across
the output transistor, if that fails then you get a smoking output
transistor VERY quickly..., so, no, the charge that remains in the diodes
is static, but if not discharged slowly can result in a higher current flow
than the diodes can handle.
I would suggest that folks do NOT draw a spark from the old B&W flybacks to
see if they are working...
John :-#)#
At 06:38 PM 4/25/2000 , John Mehrtens wrote:
>Hmmm... good question!
>
>I've been thinking about reverse current generated in the flyback when the
>CRT is discharged... Could this inductive kick be the cause of the diode
>failures? When the magnetic field collapses in a transformer, you get one
>heck of a kick in the complimentary windings. Could this cause a reverse
>current through the diodes which is well beyond their spec? Maybe even a
>potential much higher than their reverse breakdown voltage? I'd think
>that'd play quite a role! <grin>
>
>John
>
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Received on Wed Apr 26 15:17:59 2000
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