[Elecraft] K3 power switching.

[G4GNX]

Ah yes, I should have thought of that.

So presumably the status is stored in NVM, which would keep it switched on during a power outage.

I’ll now check my PSU and (if none is present) add a crowbar circuit to the output, so that it kills the PSU if it goes above 14.5 volts. 

73,

Alan. G4GNX

From: Rick Tavan N6XI 
Sent: Sunday, May 10, 2015 7:48 PM
To: G4GNX 
Subject: Re: [Elecraft] K3 power switching.

No, it's not mechanical. Since the K3 can also be powered on remotely, the front-panel switch is logical, not hard on/off. 

/Rick N6XI 

On Sun, May 10, 2015 at 8:42 AM, G4GNX <G4GNX at theatreorgans.co.uk> wrote:

  Following a mishap with a PSU, our local club’s K3 is in need of repair and I don’t want anything similar to happen to mine.

  The PSU is a linear device with a voltage control potentiometer and a meter. The operator had an issue with the PSU which was showing an output of 15 volts; the K3 was connected and working. He switched off the PSU to ‘exercise’ the potentiometer and unfortunately turned it back on with the K3 still connected and switched on. The reading was still 15 volts, so he touched the potentiometer again and the K3 started to emit smoke and died. At this time, we’re assuming that the PSU grossly over-volted.

  My question: is the power switch on the K3 mechanical? If it is, then my fears will not be realized because I ALWAYS turn on my PSU AND check the output voltage on its meter before turning on the K3.

  It will be interesting to find out what died in the K3. I hope it’s not too expensive.

  73,

  Alan. G4GNX