http://elecraft.85.s1.nabble.com/Overvoltage-Protector-tp5445892p5445993.html
... Joe, W4TV
> Scott,
>
> Great contribution. Surprising how many switch-mode supplies do not include
> OVP. AD5X created a similar circuit using a single high-peak-current
> transient suppressor:
>
>
http://www.radiodan.com/ad5x/images/Articles/VcondRevA.pdf>
> Paul, W9AC
>
> ----- Original Message -----
> From: "Scott Ellington"<
[hidden email]>
> To:<
[hidden email]>
> Sent: Friday, August 20, 2010 4:00 PM
> Subject: [Elecraft] Overvoltage Protector
>
>
>> Some power supplies, like the Samlex SEC 1235, have no built-in
>> overvoltage protection. All regulated power supplies are capable of
>> producing much more than their normal output voltage if any one of a
>> number of things fails. Linear supplies are particularly susceptible,
>> since the pass transistor can short.
>>
>> While Elecraft assures me that the K3 can survive an overvoltage with
>> minimal damage, I prefer to be on the safe side. So I designed a crowbar
>> circuit, which can be used with any 12 V power supply up to 30A. If the
>> voltage exceeds the trip point (14-16 V), it will short the power supply
>> output and, if necessary, blow a fuse.
>>
>>
>> I haven't built this one yet, but a very similar one I built in 1984
>> worked fine.
>>
>> 73,
>>
>> Scott K9MA
>>
>> Scott Ellington
>> Madison, Wisconsin
>> USA
>
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