Power Supply short protection

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Power Supply short protection

Dave, G4AON
You need plastic covers over those transistors. A cover over the output
connections wouldn't be a bad idea either.

On the subject of power supplies, I run a Racal 115-12-35CD linear power
supply and it's a nice bit of kit. They were manufactured by NewMar of
Newport Beach, CA. Several appeared here as "new old stock" in unopened
packaging on the UK surplus market a few weeks ago, but I've not seen
any since. They are rated at 35 Amps continuous up to an ambient temp of
50 deg C, and have thermal shut down, current limiting, over voltage
protection (crowbar and fuse) and are built like a tank. The only
downside is the weight - 30 lbs... at least it doesn't produce birdies
all over HF!

73 Dave, G4AON
K3/100 #80
----------------

I am running my K3 from an Astron 35M. I experienced an accidental short
circuit on the power supply and I am wondering what everyone else does about
the possibility of accidental shorts from exposed 12V wire lugs or the
exposed pass transistors on the back of power supplies (hot transistor
collectors).

In my case the PS is on the floor and you guessed it close to my shack
ground braid. While fiddling the ground braid touched one of the pass
transistor collectors and everything shut down, no damage done than
goodness. I would like a more permanent solution.

Mike Scott - AE6WA

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Re: Power Supply short protection

Kurt Cramer-2
Mike,

Just put vinyl tubing over the braid. I've used ground braid conered with
tubing for years with no problem running it around, behind and under
equipment.

73 Kurt W7QHD
----- Original Message -----
From: "Dave G4AON" <[hidden email]>
To: <[hidden email]>
Sent: Wednesday, May 21, 2008 10:20 AM
Subject: [Elecraft] Power Supply short protection



> ----------------
>
> I am running my K3 from an Astron 35M. I experienced an accidental short
> circuit on the power supply and I am wondering what everyone else does
> about
> the possibility of accidental shorts from exposed 12V wire lugs or the
> exposed pass transistors on the back of power supplies (hot transistor
> collectors).
>
> In my case the PS is on the floor and you guessed it close to my shack
> ground braid. While fiddling the ground braid touched one of the pass
> transistor collectors and everything shut down, no damage done than
> goodness. I would like a more permanent solution.
>
> Mike Scott - AE6WA
>
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
> http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com
>

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