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Re: solid state coil problem
From: Harri Suomalainen[SMTP:haba-at-cc.hut.fi]
Sent: Friday, November 14, 1997 12:13 PM
To: Tesla List
Subject: Re: solid state coil problem
On Thu, 13 Nov 1997, Tesla List wrote:
[core saturation]
> Thanks! That is probably the solution to my problem!
>I don't have pin
> #10 connected at all, which happens to be the shut down pin. I think
> what I,ll do is use a 555 to shut down the both outputs at about 300hz
> or lower. I may have to play around with the freq. and or the duty cycle
> of the 555 for best results. Thanks!
Shutting it down every now and then is not the solution! You need to
shut the conducting fet during the conduction cycle prematurely if
the core is getting saturated. It will not take many switching cyckles
to saturate the core, usually a few will do the destruction. In worst
case even a single pulse may saturate the core! You need *pulse-by-pulse*
current limiting. Without one you will just pop the fets. Putting the
system on and off every now and then at 300Hz or 10kHz or whatever is
not the solution. It will help nothing.
--
See "Malin Tunic: Chemistry of structure - function references in cheese" for
further details!
Harri.Suomalainen-at-hut.fi - PGP key available by fingering haba-at-alpha.hut.fi