[Elecraft] Highest power supply voltage for K2?

[Bob - W5BIG]

Hi Dan,

I would be very hesitant to use this technique on expensive equipment.
Gradually turning up the voltage while watching the current can lead to a
problem that doesn't show up immediately since components can be operated at
a higher than normal temperature for a while but their failure rate goes up.
After a few hours, days, weeks, your circuit may be damaged.

The determination of absolute max input voltage depends on a lot of factors
and it's a major engineering problem to determine the safe value.  For
example, the power rating of the regulators depends on how they are mounted.
It may not be convenient to measure their case temperature to characterize a
particular application. Alternatively, one can be conservative and use the
databook values.  Since the guys at Elecraft say 15V, I would go along with
that.  If the power supply is not well regulated, consider the max value
with no load.

73/ Bob - W5BIG


----- Original Message -----
From: "Dan Barker" <dbarker at visioncomm.net>
To: "Elecraft" <elecraft at mailman.qth.net>
Sent: Tuesday, November 30, 2004 7:29 AM
Subject: RE: [Elecraft] Highest power supply voltage for K2?


> I've always done the following to see if I was going to toast something.
> Maybe someone can tell me the error of may ways (the last thing I did this
> on was a $1,400 Video Camera - if the method is dangerous, I'll stop!).
>
> I hook the 6V Camera up to a 6V power supply (actually a variable voltage
> PS) through an ammeter. I slowly advance the voltage (toward the 9.6V
target
> of the high-capacity batteries stolen from my Electric Zagi model
airplane).
>
> I figure if the current goes up, I'm going to cook something. If the
current
> decreases, then the power being dissipated is roughly constant so I'm not
> cooking anything.
>
>