[TenTec] Dumb question about breaker

[denton]

Hi...here is something on crowbars that might be of help..
I homebrewed my own power supply and run  crowbars clamp across the filter
caps....installing the crowbar across the output will sometimes open up one
or more pass transistors. I also run another smaller eletrolytic cap across
the output of the power supply to keep the crowbar from getting over active
and firing when hooking up something while the power supply is on. The
crowbar still does its thing but isnt so sensitive as it was before.
----- Original Message -----
From: Mark Hinkel <mrhinkel at ix.netcom.com>
To: <tentec at contesting.com>
Sent: Monday, February 03, 2003 9:06 PM
Subject: Re: [TenTec] Dumb question about breaker


> Hi Tim,
>
> Well, there's one more question...
>
> Is your current P/S over voltage protected by a crowbar??
>
> Many older P/S were designed such that if the regulator shorted you'd
> end up with full voltage going to the base of the pass transistor (full
> on).  One of the guy in the local club had an Astron that burned up, and
> applied about 22v to his radio.  NOT good...  it burned the radio up as
> well.  This doesn't happen often, but when it does, it'll ruin your
> whole day.
>
> A crowbar is a very easy device to install.  Just place it in the
> circuit (parallel) AFTER the circuit breaker.  Turn up the adjustment on
> your P/S, about a volt or volt and a half over where you normally run
> things.  Then adjust down on the crowbar screw.  When it trips the
> breaker, that's it.  Now adjust your P/S back to it's normal voltage.
> If the P/S should ever go over voltage, it'll trip the breaker and save
> you a really big expense.
>
> Mark Hinkel   WA3QVU
> Willow Grove, Pa.
>
>
> tlogan7 at cox.net wrote:
> >
> > Thanks guys and gals - got my answer.
> > >
> > > From: KD5NWA <KD5NWA at MBayona.com>
> > > Date: 2003/02/03 Mon PM 05:49:01 EST
> > > To: tentec at contesting.com
> > > Subject: Re: [TenTec] Dumb question about breaker
> > >
> > > Yes, generally you fuse the positive wire otherwise the radio or
antenna
> > > being grounded provides an alternate path to ground and for current to
> > > continue flowing. Specially if you use it in a car.
> > >
> > >
> > > At 04:31 PM 2/3/2003, you wrote:
> > > >If not using a Ten Tec PS, the Airpax breaker should be installed in
> > > >series in the positive side of the power cord, right? 73/Tim NZ7C
> > > >
> > > >_______________________________________________
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> > >
> > > Cecil
> > > KD5NWA
> > >
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