Dave,
Were I to do the high-power model, I'd probably use the same Anderson
power-pole connectors as in the K2/100 simply to retain compatibility
with everything else.
Alan
Alan D. Wilcox, W3DVX
570-321-1516
[EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>
http://WilcoxEngineering.com
Williamsport, PA 17701
------------------------------------------------------------------------
David Lankshear wrote:
Hi Alan.
Well, the K2/100's cable has an inline fuse at the PSU end, if
constructed in accordance with Elecraft's instructions although a
separate, faster blow fuse could be incorporated into the crowbar box.
I must confess that I'd originally thought of incorporating a
crowbar-in-a-box, but the idea was swamped with other things and I
simply haven't done anything about it - until you jogged my memory.
I have two linear and one switchmode power supply here; all are
capable of supplying 13v8 at 30 amps plus so supply fuses are
important to me. All of the units are capable of providing some
variation in output voltage by internal adjustment. I would be
concerned if the voltage crept up a little but not outside the
supply's parameters, which might cause the K2/100 to draw nearer 30A
on transmit.
The crowbar could be permanently fitted in line and connectors could
be as simple as two hefty strips of PCB to which the input and output
leads are soldered. If it's a hefty beast, it might find favour with
users of other equipment that are supplied at 12v and many amps - (the
"universal" crowbar?)
73 DaveL G3TJP
----- Original Message ----- From: "Alan D. Wilcox"
<[EMAIL PROTECTED]>
To: <elecraft@mailman.qth.net>
Cc: "David Lankshear" <[EMAIL PROTECTED]>
Sent: Tuesday, October 30, 2007 12:32 AM
Subject: Re: [Elecraft] Question: Over-voltage protection (OVP) for
K2, K1
Dave,
If I were to do an OVP for a K2/100 ...
1. Different connectors,
2. A circuit breaker (a 20+ A supply would cause serious damage
without a fuse or breaker),
3. Change OVP-12 to the OVP-24 (20A continuous, 30A intermittent),
4. Bigger case, probably metal to act as heat sink (just in case).
I would expect a 20-30A supply to have protection, so the above
wouldn't be necessary. HOWEVER, the supply that inspired the project
to start with was just such a supply, so maybe such an OVP would be a
good idea. Hmmm.
Alan
Alan D. Wilcox, W3DVX
570-321-1516
[EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>
http://WilcoxEngineering.com
http://www.eham.net/reviews/detail/6768 ... for Client Comments
Williamsport, PA 17701
------------------------------------------------------------------------
David Lankshear wrote:
That's fine for a barefoot K2, Alan, but what about the K2/100?
Re Matt's comment - surely you don't need current sense resistors
for an over VOLTAGE trip? Generally, the minimum component count
for a brute force crowbar is 4. SCR, zener, resistor, capacitor.
73 DaveL G3TJP
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