Searching \ for '[EE] Tiny multimeter' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/index.htm?key=tiny+multimeter
Search entire site for: 'Tiny multimeter'.

Exact match. Not showing close matches.
PICList Thread
'[EE] Tiny multimeter'
2005\09\06@154642 by Mike Hord

picon face
I'm looking for a truly credit card sized multimeter.

It doesn't need to be terribly advanced, just something
that will fit in my wallet (I do have an inordinately fat
wallet, in all ways but the one that counts) and can be
used to give me an idea of whether the voltage at a
node is 5, 50, or 100 volts.

I'll accept accuracy as poor as, say, 5-10%.  I'd like
DC and AC volts and continuity; anything else is gravy
and likely to just add to the size of the device.
Obviously, this isn't something that'll be doing precision
work, just something so that when away from my desk
I can answer the basic question of "Is it getting enough
power?" with relative certainty, without having to carry
yet another big object around with me.

For further reference, "credit card sized" denotes about
80x55mm or so, and not more that 7 or 8 mm thick.
Leads should not add significantly to the size, or should
be easily replaced.

I do carry a PDA, but am hesitant to use a solution
which could invite higher voltages of AC into it.

Mike H.

2005\09\06@165220 by PicDude

flavicon
face
Can you really fit 7-8mm in your wallet?  I still think that's pretty thick.

I would think you could probably build a crude but thin bargraph-only
voltmeter/ohmeter from 1/32" PCB, some SMT leds, some SSOP-sized comparators
and other passives.  Not sure if the LM3914 comes in a small enough package
though.  Or better -- put a PIC in there.  For range changes, there are some
really thin tact switches -- like 2mm or so.  I say bargraph-only since all
the SMT led's I've seen are still pretty thick, but you might be able to put
an LCD on there.

Not sure how to handle the leads, but perhaps you could modify/adapt one of
those "roll-up" type RJ11 modem cables?

Cheers,
-Neil.



On Tuesday 06 September 2005 02:46 pm, Mike Hord scribbled:
{Quote hidden}

2005\09\06@183305 by Russell McMahon

face
flavicon
face
> I'm looking for a truly credit card sized multimeter.

> used to give me an idea of whether the voltage at a
> node is 5, 50, or 100 volts.

> I'll accept accuracy as poor as, say, 5-10%.  I'd like
> DC and AC volts and continuity; anything else is gravy
> and likely to just add to the size of the device.


I like the bargraph idea.

Even simpler would be a voltage to period converter (charge a cap)
that pulsed an LED. Rough accuracy by eye. better accuracy by counting
mentally. Extremely good accuracy possible with stopwatch (all
engineers have a stopwatch with them at all times, don't they).

AC/DC easy. Continuity easy.
Sounds like a good idea. Where's my LEDs ...

Could piezo beep the output.

BUT you can already get more conventional pen shaped/sized meters
which would arguably be as convenient.

I'd thought a keyring torch/pen combo would be useful. That could be a
torch/pen/meter/... ?



       RM

2005\09\06@184026 by Jinx

face picon face
> the SMT led's I've seen are still pretty thick

Cellphone k/b LEDs are very thin, and there are plenty of
discarded cellphones. I don't think it would be too difficult
to make an auto-ranging voltmeter with a PIC A2D. Maybe
assign a resistive divider to each A2D i/p of an SMT PIC
and scan them for the highest one that isn't full-scale, then
light the appropriate LED(s) directly or through a driver

2005\09\06@191758 by PicDude

flavicon
face
On Tuesday 06 September 2005 05:40 pm, Jinx scribbled:
> > the SMT led's I've seen are still pretty thick
>
> Cellphone k/b LEDs are very thin, and there are plenty of
> discarded cellphones. I don't think it would be too difficult
> to make an auto-ranging voltmeter with a PIC A2D. Maybe
> assign a resistive divider to each A2D i/p of an SMT PIC
> and scan them for the highest one that isn't full-scale, then
> light the appropriate LED(s) directly or through a driver

Oops -- I meant SMT 7-segment LED's.  The 1206-sized led's are really nice
though.

Cheers,
-Neil.


2005\09\06@234033 by William Chops Westfield

face picon face

>> I'm looking for a truly credit card sized multimeter.
>>

I bet you could get pretty close with The 'superprobe' done in SMT
with an LCD display instead of LED:

http://members.cox.net/berniekm/super.html

High voltage AC measurement would be a bit of a problem; I don't know
that the usual blocking cap would fit in the space you have available.

BillW

2005\09\07@040238 by Alan B. Pearce

face picon face
>Oops -- I meant SMT 7-segment LED's.  The 1206-sized
>led's are really nice though.

So why not make ones own 7 seg display out of individual leds. For the type
of instrument envisaged I would put two leds in each segment, to get enough
shape to them. If one wanted only one led/seg then glue a bit of clear
plastic sprue from a plastic kit onto the top of the led to make a segment
bar.

2005\09\07@095500 by Mike Hord

picon face
> >> I'm looking for a truly credit card sized multimeter.
> >>
>
> I bet you could get pretty close with The 'superprobe' done in SMT
> with an LCD display instead of LED:
>
> http://members.cox.net/berniekm/super.html
>
> High voltage AC measurement would be a bit of a problem; I don't know
> that the usual blocking cap would fit in the space you have available.

Wow.  That's a heck of a project.  Very impressive.

I probably could get it all into a thin enough case.

Mike H.

2005\09\07@100006 by Mike Hord

picon face
> Can you really fit 7-8mm in your wallet?  I still think that's pretty thick.

Yes.  Without question.  It would be replacing a "credit-card toolkit"
which is about 7 mm thick; I don't really need that any more, as I
now carry a Gerber multitool on my belt.

> I would think you could probably build a crude but thin bargraph-only
> voltmeter/ohmeter from 1/32" PCB, some SMT leds, some SSOP-sized comparators
> and other passives.  Not sure if the LM3914 comes in a small enough package
> though.  Or better -- put a PIC in there.  For range changes, there are some
> really thin tact switches -- like 2mm or so.  I say bargraph-only since all
> the SMT led's I've seen are still pretty thick, but you might be able to put
> an LCD on there.

Building one was always an option, of course, but not my favorite.  I have
no doubt that I could manage it, but It may (will) be thicker than I'd like.
The real problem thickness-wise is the need to measure AC.  If it were
only for DC, I'd leave the PCB mostly bare or put some token covering on
it.  For AC, I REALLY need to put a good, thick case there to keep my
pinkies safe.

> Not sure how to handle the leads, but perhaps you could modify/adapt one of
> those "roll-up" type RJ11 modem cables?

Probably just thin, short wires.  Say, 30 gauge wire wrap?

Mike H.

2005\09\07@100700 by Mike Hord

picon face
> I like the bargraph idea.
>
> Even simpler would be a voltage to period converter (charge a cap)
> that pulsed an LED. Rough accuracy by eye. better accuracy by counting
> mentally. Extremely good accuracy possible with stopwatch (all
> engineers have a stopwatch with them at all times, don't they).

This engineer doesn't even wear a wristwatch... ;-)  Not a bad idea, though.
Once I have a feel for the frequency generated by a "good" voltage, I should
be able to identify that again later.

> BUT you can already get more conventional pen shaped/sized meters
> which would arguably be as convenient.
>
> I'd thought a keyring torch/pen combo would be useful. That could be a
> torch/pen/meter/... ?

I already have a pen/light/laser/PDA stylus combo.

Mike H.

2005\09\07@101249 by marcel

flavicon
face
Mike Hord <spam_OUTmike.hordTakeThisOuTspamgmail.com> wrote:

> > Can you really fit 7-8mm in your wallet?  I still think that's pretty
thick.
>
> Yes.  Without question.  It would be replacing a "credit-card toolkit"
> which is about 7 mm thick; I don't really need that any more, as I
> now carry a Gerber multitool on my belt.
>

Do you also have karate-grip action and an optional accessories kit, sold
separately?


2005\09\07@105140 by Michael Rigby-Jones

picon face


{Quote hidden}

Doesn't quite meet your size specs, but is a full autoranging DMM

http://www.web-tronics.com/mulcredcarsi.html

Regards

Mike

=======================================================================
This e-mail is intended for the person it is addressed to only. The
information contained in it may be confidential and/or protected by
law. If you are not the intended recipient of this message, you must
not make any use of this information, or copy or show it to any
person. Please contact us immediately to tell us that you have
received this e-mail, and return the original to us. Any use,
forwarding, printing or copying of this message is strictly prohibited.
No part of this message can be considered a request for goods or
services.
=======================================================================

2005\09\07@105340 by Jake Anderson

flavicon
face
amorphous blob with bluetooth to your PDA?
lots more possibilites then, with a decent enough ADC you could even do
audio (or low speed digital) osciliscope functions
cool factor 9.27 Mr Sulu

> {Original Message removed}

2005\09\07@132718 by Paul James E.

picon face

Check out Microchip Technical Bulletin  TB-083.
This, or a derivitive, might fill your need.

                           Regards,

                             Jim



>
>
>>{Original Message removed}

2005\09\07@140839 by Dave Lag

picon face
ww1.microchip.com/downloads/en/DeviceDoc/91083A.pdf


Paul James E. wrote:
>  Check out Microchip Technical Bulletin  TB-083.
>  This, or a derivitive, might fill your need.
>
>                             Regards,
>
>                               Jim
>>>-----Original Message-----
>>>
>>>I'm looking for a truly credit card sized multimeter.
>>>
.....

>>>It doesn't need to be terribly advanced, just something
.....
>>Mike

2005\09\08@063008 by Howard Winter

face
flavicon
picon face
Mike,

On Wed, 7 Sep 2005 15:51:38 +0100, Michael Rigby-Jones wrote:
>...<
> Doesn't quite meet your size specs, but is a full autoranging DMM
>
> http://www.web-tronics.com/mulcredcarsi.html

I have one very similar to this (it's yellow but apparently the same otherwise) and it's very hand to carry
about, but "credit-card sized" it aint - except for very large values of credit card (!)  :-)

If they sold it here under that description, they'd be in trouble under the Trades Descriptions Act...

Cheers,



Howard Winter
St.Albans, England


2005\09\08@094039 by Mike Hord

picon face
>From Lee Jones, off list, by permission:

> I'm looking for a truly credit card sized multimeter.

Radio Shack (US) used to have some pretty small voltmeters.
I've been carrying one in my valise for about a decade.  It
is credit card size but about 1/2" thick.  Leads coil up
inside the top cover.  As I recall, it was $15'ish.

It tends to be a little flakey, but it's great for rough
voltage or continuity checks when your real toolkit is a
half hour driving time away.  Overall, it's worth carrying.

I think they used to have a much thinner one.  Quick check
of http://www.radioshack.com shows that 22-820 appears to be the
smallest one they now offer.  Dimensions are not listed; it
just says "shirt pocket" size in owner's manual.  It looks
like an updated version of what I've used for years.  And
it's now $30.

                                               Lee Jones

2005\09\08@095330 by Mike Hord

picon face
As usual, Google knows best, as Russell would say.
Even if they didn't realize it.

www.marteltesttools.com/products.php?cat=114&action=detail&id=73
http://tinyurl.com/e2f7x

>From a banner ad next to this thread in my Gmail account.

Looks to be about the "right" size; if I'm REALLY hard on
myself, I might be able to bury most of the works under it,
using a 10F or 12F PIC to autorange and select between
AC and DC.

Mike H.

More... (looser matching)
- Last day of these posts
- In 2005 , 2006 only
- Today
- New search...