Author Topic: Lets build a multimeter without a range selector  (Read 6144 times)

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Offline StonentTopic starter

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Offline Bryan

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Re: Lets build a multimeter without a range selector
« Reply #1 on: October 31, 2013, 10:52:52 am »
And you can use paper clips for leads, Maybe double up the clips for the 1000v input.  ;D ;D
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Offline Bored@Work

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Re: Lets build a multimeter without a range selector
« Reply #2 on: October 31, 2013, 11:34:01 am »
Not too uncommon in the old days. There is e.g. the rather popular Supertester 680 in its various incarnations

http://www.radiomuseum.org/r/ice_supertester_680g680.html
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Offline amyk

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Re: Lets build a multimeter without a range selector
« Reply #3 on: October 31, 2013, 01:35:03 pm »
It seems to lessen the chances of leaving the probe leads in the amps socket if you want to measure voltage... since switching to volts implies moving the probes.
 

Offline dfmischler

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Re: Lets build a multimeter without a range selector
« Reply #4 on: October 31, 2013, 05:15:51 pm »
I had one of those when I was a kid (probably got it for Christmas or a birthday).  It worked, but I always wanted better.  I upgraded as soon as I could, but I don't remember what I had next..  I don't think I had a digital multimeter until I was out of high school...
 

Offline N2IXK

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Re: Lets build a multimeter without a range selector
« Reply #5 on: October 31, 2013, 05:40:25 pm »
That was actually the first multimeter I ever owned as a kid. 1000 ohms/volt, IIRC. Think they cost 6-7 bucks back in the late 70s, maybe a buck or 2 cheaper if you bought the kit version.  And it does have a range selector--you plug the red lead into the appropriate (15, 150, 1000) jack for the voltage you want to measure.

Sure, the thing is a joke now, but back then it was just the ticket for a kid playing around with dry cells, light bulbs, and switches.
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Offline AG6QR

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Re: Lets build a multimeter without a range selector
« Reply #6 on: October 31, 2013, 06:24:44 pm »
I also had one of those, and still have it.  It cost $6.98 in 1978, which I know because mine still has the box with its price tag.  Mine is probably an earlier version than that one, because mine lacks some cosmetic safety warnings present in that photo -- the red lighting bolt near the 1000V terminal, and the extra text around the AC-V and DC-ohm terminals.

I bought mine shortly after I got my first car, and I used it for a fair bit of basic diagnostic work on that car.  The meter has outlasted the car by decades.
 

Offline StonentTopic starter

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Re: Lets build a multimeter without a range selector
« Reply #7 on: October 31, 2013, 06:43:37 pm »
I also had one of those, and still have it.  It cost $6.98 in 1978, which I know because mine still has the box with its price tag.  Mine is probably an earlier version than that one, because mine lacks some cosmetic safety warnings present in that photo -- the red lighting bolt near the 1000V terminal, and the extra text around the AC-V and DC-ohm terminals.

I bought mine shortly after I got my first car, and I used it for a fair bit of basic diagnostic work on that car.  The meter has outlasted the car by decades.

I found another variant last night with a more stylized Micronta logo that had 3 horizontal stripes in front of the logo.



Then there's this one with embossed labels and no logo

« Last Edit: October 31, 2013, 06:50:34 pm by Stonent »
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Offline AG6QR

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Re: Lets build a multimeter without a range selector
« Reply #8 on: November 01, 2013, 04:32:23 am »
I dug out my meter and snapped a pic.  My box has seen a lot of wear.  Notice that the logo is a little big different than the box in Stonent's post.  See especially the "CR" in "Micronta".  But the meter itself appears to be identical.


And for a bonus, here's a teardown:



Not only does this meter lack a range switch, it has no circuit board at all!  All point-to-point wiring.  No protection circuitry, either.  There's some green crud on the wire that went from the positive battery contact to the kOhms jack, from leaving the battery there too long.
 

Offline retiredcaps

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Re: Lets build a multimeter without a range selector
« Reply #9 on: November 01, 2013, 04:50:11 am »
You can build a multimeter without a range selector.  Here is one that just has an on/off button.  Cat III rated and 560 hours on 2 AA.

See

http://www.testproductsintl.com/products/dmms/100/100%20Product%20Sheet%2002.11.pdf

My Fluke 12 has a similar feature called Vchek, but I never use it.
« Last Edit: November 01, 2013, 07:24:20 am by retiredcaps »
 

Offline ivaylo

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Re: Lets build a multimeter without a range selector
« Reply #10 on: November 01, 2013, 07:05:49 am »
Oh boy... Here is the first I had . Ugly beast...
 

Offline Gall

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Re: Lets build a multimeter without a range selector
« Reply #11 on: November 01, 2013, 01:54:18 pm »
That Tse20 is too new. The real old Tse20 should look like that:



Yes,  they both are the same USSR model, just different years of manufacture.
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Offline ivaylo

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Re: Lets build a multimeter without a range selector
« Reply #12 on: November 01, 2013, 03:13:56 pm »
Quote
The real old Tse20 should look like...

No no, that is exactly what's ridiculous about them. Not that they were some old technology, but that they kept being manufactured almost into the 90s, maybe even later...
 

Offline Hydrawerk

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Amazing machines. https://www.youtube.com/user/denha (It is not me...)
 


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