[Elecraft] [K3] Overvoltage protection?

[Hardy Landskov]

To all on the net:
I bought an AS35A at a swap meet and so far it's doing it's thing just fine 
with the K3.  But there was no paper work. Are there tests I can do that say 
yeh verily this thing works as designed?
73 N7RT

----- Original Message ----- 
From: "Tom Hammond" <n0ss at embarqmail.com>
To: "Dan & Jean" <dmlbjl at gmail.com>; <elecraft at mailman.qth.net>
Sent: Sunday, February 28, 2010 7:35 PM
Subject: Re: [Elecraft] [K3] Overvoltage protection?


> Dan:
>
> If the Astron is working AS INTENDED, when the OVP SCR fires, the UA723 
> VReg
> will immediately go into over-current protect mode, reducing the output 
> current
> to <1A WITHOUT damaging ANYTHING!  Same as if you placed a short directly
> across the output terminals of the supply.
>
> The ONLY time the fuse should blow is if the p ass transistors shorted.
>
> 73,
>
> Tom Hammond   N0SS
>
> At 20:28 02/28/2010, you wrote:
>>I recently purchased a 35 amp Astron power supply at a hamfest (in
>>great condition).  Upon inspection, I found that the crowbar SCR had
>>failed, and had been removed.
>>
>>Although I've replaced the SCR, I'm wondering if the K3 has
>>overvoltage protection of some kind?
>>
>>As an aside, I would like to test the crowbar circuit in the Astron,
>>but with that big capacitor in there, I'm kind of hesitant.  That
>>big capacitor would have to discharge before the primary fuse would
>>blow (maybe blowing the SCR)--right?  I'm thinking of putting a 25
>>amp fuse in series with the capacitor.  Anyone address this before?
>>
>>Thanks,
>>Dan - W4TQ
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