Can you identify this button?

Posted on Saturday, April 23rd, 2011 in help, idle by Ian

arhi writes:

I have some old (very old) KONTRON DMM 3002 bench top digital multimeter… there is a button on the thing that I have no clue what it does…

So if you look at the pic, the button in question is the pressed one, or if not clear which one is pressed, the one with “–” sign.

When I switch the dmm to the — the display count from 0000 up approx 1 per sec, the output on the hi-lo is 5 or 10 or 12V depending on the white buttons, and it is constant (scope show less then +-10mV 50Hz hum)

I tried attaching 100nF – nothing changed (still counting, still same speed), tried diode too, nothing happened .. so maybe it is a counter :D .. donno what would that be useful for but ..

Anyone know what this is?

Via the forum.

This entry was posted on Saturday, April 23rd, 2011 at 10:56 am and is filed under help, idle. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.

4 Responses to “Can you identify this button?”

  1. JP says:

    Maybe it just tests for continuity??

  2. Johnny (Remember me) says:

    It’s the ‘Destroy the World’ button. You need to operate it in conjunction with a key, which you apparently do not have. The key is available from Maplin stores, and sometimes cheaply on eBay.

  3. hamed yazdan says:


  4. hamed yazdan says:


Leave a Reply

Notify me of followup comments via e-mail. You can also subscribe without commenting.

Recent Comments

  • Drone: So these go for around $330 USD and NO published calibration procedure online or otherwise? Given what's inside - I don't think I'll be considering...
  • Pekka Akselin: This is ridiculous!? :-) We are back at 256(!) byte EPROMs that needed multiple, a handful, of voltages to run! :-(
  • KH: Let's try a back-of-envelope calc balancing energies. From MCP1700 datasheet, there are graphs for a 200mA load step. Estimate the energy shortfall as 12uJ. Say...
  • Daniel: It's been a week and my comment is still awaiting moderation. Apparently the CIA doesn't want their involvement known?
  • KH: Agree, so okay, I guess he must have learned from somewhere. 100nF and 1000uF is so far apart, that was jarring; it's more magic incantation...