On Wed, 31 Jan 2007 16:03:16 -0500, "Bruce W.1"
<s...@noDirectEmail.com> wrote:

>David L. Jones wrote:
>> 
>> Less than 1" wide:
>> http://au.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=9932909
>> Standard 200mV FSD, just make your own input scaler.
>> 
>> Dave :)
>> 
>
>=================================================
>
>Expensive little guy isn't it? 

Newarkinone shows the price as Can$27.52 - wonder what price units
that Farnell site uses?


-- 
Peter Bennett, VE7CEI  
peterbb4 (at) interchange.ubc.ca  
new newsgroup users info : http://vancouver-webpages.com/nnq
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On Feb 1, 12:49 pm, Peter Bennett <pete...@somewhere.invalid> wrote:
> On Wed, 31 Jan 2007 16:03:16 -0500, "Bruce W.1"
>
> <s...@noDirectEmail.com> wrote:
> >David L. Jones wrote:
>
> >> Less than 1" wide:
> >>http://au.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=9932909
> >> Standard 200mV FSD, just make your own input scaler.
>
> >> Dave :)
>
> >=================================================
>
> >Expensive little guy isn't it?
>
> Newarkinone shows the price as Can$27.52 - wonder what price units
> that Farnell site uses?

I posted the link to the Australian Farnell site, so that price is in
Aussie dollars

Dave :)

Bruce W.1 wrote:
> 
> 
> This will be part of a 12V bicycle light system.  It will mount in a 
> small box, probably on the handlebars.  It's measurement range should be 
> about 8 to 20 volts.
> 
>  
> Does anyone know of a really tiny voltmeter?
> 
> Thanks for your help.

Why not re-engineer the whole system !
Replace the Headlight (bulb) with a Multi-Ultra Bright White LED Array. 
They don't burn out or drop filaments and require less battery power and 
will operate on weak batteries, thus eliminate the need to closely 
monitor the battery Voltage or troubleshoot a no Light Output Condition.
	Same story for the tail-light ! Multi Red LED Array.
All for the price of any DVM.
Yukio YANO

On Feb 1, 8:03 am, "Bruce W.1" <s...@noDirectEmail.com> wrote:
> David L. Jones wrote:
>
> > Less than 1" wide:
> >http://au.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=9932909
> > Standard 200mV FSD, just make your own input scaler.
>
> > Dave :)
>
> =================================================
>
> Expensive little guy isn't it?  My battery pack (12 C-cells) exceeds its
> [14VDC] voltage rating.
>
> BTW, I'm also building a Pulse Width Modulation circuit so I don't fry
> my 12VDC lightbulbs.  This voltmeter will monitor its input and output
> voltage.

I'm with the others on this, re-thinking what you actually need is
probably a good idea. I can't see any benefit of having an LCD display
for the pack voltage, esp at night when you'll need to backlight it,
and it could be distracting.
If you simply what to know when the batteries are getting low then a
simple single (or multiple) "low batt" LED will do.
Use a DC-DC converter to give you a constant brightness on your lamp,
and maximize the use of battery capacity.
Are you using primary Alkaline cells or rechargables?

Dave :)

On Jan 31, 8:45 pm, "Bruce W.1" <s...@noDirectEmail.com> wrote:
> I'm looking for the very smallest -- panel mount -- LCD voltmeter.  My
> Google searches have been dissapointing.  The smallest I could find is
> about 2" wide.
>
> This will be part of a 12V bicycle light system.  It will mount in a
> small box, probably on the handlebars.  It's measurement range should be
> about 8 to 20 volts.
>
> A voltmeter is not complicated.  I would think that one could easily be
> made in a 1/2" square.
>
> Does anyone know of a really tiny voltmeter?
>
> Thanks for your help.

You can build one using one pic ADC ch. but you must set vref- 8V and
vref+ 20V or you can just divide voltage range to 0-5 V. you can read
the measurement with two 7 segment. google "voltmeter with pic" tags
this shoud help.

On Wed, 31 Jan 2007 18:45:07 GMT, "Bruce W.1"
<s...@noDirectEmail.com> wrote:

>I'm looking for the very smallest -- panel mount -- LCD voltmeter.  My 
>Google searches have been dissapointing.  The smallest I could find is 
>about 2" wide.
>
>This will be part of a 12V bicycle light system.  It will mount in a 
>small box, probably on the handlebars.  It's measurement range should be 
>about 8 to 20 volts.
>
>A voltmeter is not complicated.  I would think that one could easily be 
>made in a 1/2" square.
>
>Does anyone know of a really tiny voltmeter?
>
>Thanks for your help.

Cheap and tiny, but requiring a bit of cobbling:
Get a cheap DMM (often on sale at Harbor Freight
for under $5).  These have displays about 1/2"
high and 2" long.  (Hey. you have to be able to
read the display!  half-inch square would be tought
unless you had really tiny digits..)  Inside the case
is a big rotary range selector switch and a little
chip under a black blob.  Just figure out which
connections are made for the range you want,
hot-wire those and eliminate the switch, and 
install in the smaller case of your choice.

Oh, the DMMs run on 9V, but they don't draw
much juice so you can probably drop the 12V
with a simple zener circuit.

Best regards,


Bob Masta
 
            D A Q A R T A
Data AcQuisition And Real-Time Analysis
           www.daqarta.com
Scope, Spectrum, Spectrogram, Signal Generator
    Science with your sound card!

On Thu, 01 Feb 2007 13:02:01 GMT, N...@daqarta.com (Bob Masta)
wrote:

>On Wed, 31 Jan 2007 18:45:07 GMT, "Bruce W.1"
><s...@noDirectEmail.com> wrote:
>
>>I'm looking for the very smallest -- panel mount -- LCD voltmeter.  My 
>>Google searches have been dissapointing.  The smallest I could find is 
>>about 2" wide.
>>
>>This will be part of a 12V bicycle light system.  It will mount in a 
>>small box, probably on the handlebars.  It's measurement range should be 
>>about 8 to 20 volts.
>>
>>A voltmeter is not complicated.  I would think that one could easily be 
>>made in a 1/2" square.
>>
>>Does anyone know of a really tiny voltmeter?
>>
>>Thanks for your help.
>
>Cheap and tiny, but requiring a bit of cobbling:
>Get a cheap DMM (often on sale at Harbor Freight
>for under $5).  These have displays about 1/2"
>high and 2" long.  (Hey. you have to be able to
>read the display!  half-inch square would be tought
>unless you had really tiny digits..)  Inside the case
>is a big rotary range selector switch and a little
>chip under a black blob.  Just figure out which
>connections are made for the range you want,
>hot-wire those and eliminate the switch, and 
>install in the smaller case of your choice.
>
>Oh, the DMMs run on 9V, but they don't draw
>much juice so you can probably drop the 12V
>with a simple zener circuit.
>
>Best regards,
>
>
>Bob Masta

Definitely inexpensive.  

Some (many) DM's can't measure their own battery supply - something
the op may run into with the meter he chooses.

The problem can be solved with some diodes to shift the ground
reference, but that may make it necessary to change the voltage
divider too.

This is for a bicycle lighting system?  Needs the back light if it is
LCD.  I'd go with a color LED bar/dot display and just blink it twice
a second.  Turn the brightness up during daylight if it is needed, and
way down at night.
-- 

----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==----
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On Jan 31, 9:04 pm, e...@FreeNet.Carleton.CA (Michael Black) wrote:
> "David L. Jones" (altz...@gmail.com) writes:
>
>
>
> > On Feb 1, 7:03 am, "Bruce W.1" <s...@noDirectEmail.com> wrote:
> >> David L. Jones wrote:
>
> >> > Less than 1" wide:
> >> >http://au.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=9932909
> >> > Standard 200mV FSD, just make your own input scaler.
>
> >> > Dave :)
>
> >> =================================================
>
> >> Expensive little guy isn't it?
>
> > What's your time worth?
> > If it's worth nothing to you then yes, it's expensive, otherwise it's
> > not so expensive.
> > You might be able to get it cheaper elsewhere.
>
> Of course, one can make a tradeoff.  Go bigger, and the selection goes
> up and the prices drop.  Low end DMMs have become so cheap that using
> one as a dedicated meter is not outrageous.  But then, the original
> poster wants small.
>
> Or get a cheap analog panel meter, even one of those surplus "tuning
> meters" that have a calibration that doesn't mean a thing.  Make
> the scale.  Put a zener diode in series to get expanded scale, so it
> reads the range you want.
>
> The poster can figure out what they really need the meter for, and
> then come up with some scheme that does the job without overkill.  Some
> LEDs and comparators, or one of those voltage level ICs (their proper
> name escapes me at the moment), so they get discrete steps.

Do you mean LM3914
http://www.jameco.com/Jameco/Products/ProdDS/24230.pdf

I used 2 of those and a pair of 10 LED bargraphs to make a very nice
20 LED analog voltmeter
for my motorcycle, which has charging problems

The LM 3914 can be used anywhere from 3 to 18 volts or so with Very
minimal support circuitry.
Offhand, I believe the OP could make a 10 segment meter with:
an LM3914, the LED bargraph and 2 or 3 resistors.
If he needs to calibrate the upper and lower thresholds more
precisely, he would need to add two pots to that.

> Maybe
> making sure the voltage is merely "good" and "too low" is sufficient,
> so two comparators driving two LEDs is sufficient, or there are neater
> schemes to have LEDs turn on at a given voltage.
>

Bob Masta wrote:
> 
> 
> Cheap and tiny, but requiring a bit of cobbling:
> Get a cheap DMM (often on sale at Harbor Freight
> for under $5).  These have displays about 1/2"
> high and 2" long.  (Hey. you have to be able to
> read the display!  half-inch square would be tought
> unless you had really tiny digits..)  Inside the case
> is a big rotary range selector switch and a little
> chip under a black blob.  Just figure out which
> connections are made for the range you want,
> hot-wire those and eliminate the switch, and 
> install in the smaller case of your choice.
> 
> Oh, the DMMs run on 9V, but they don't draw
> much juice so you can probably drop the 12V
> with a simple zener circuit.
> 
> Best regards,
> 
> 
> Bob Masta
>  
>             D A Q A R T A
> Data AcQuisition And Real-Time Analysis
>            www.daqarta.com
> Scope, Spectrum, Spectrogram, Signal Generator
>     Science with your sound card!
===============================================

That's beginning to look like a good option.  I really don't want to get 
into programming a pic chip.  This is getting pretty complicated anyway. 
  Maybe I'll just fix it at 13.2 volts and call it a day, and take along 
my mini RS multimeter.

There are some wonderful HID (metal halide) lights on the market but 
they cost big bucks.

For tail lighting I'm using a Cateye TL-LD1000 which is red LEDs and has 
its own AA batteries.  This and an amber strobe (12 volts) from All 
Electronics, this will run off the battery pack (12 alkaline C-cells).

I'm using alkalines because I wouln't always have the ability to charge 
rechargeables, but you can always buy alkalines.

The headlights, at this time will probably be two 12 volt 10-watt MR16 
bulbs (one flood, one spot).  Though finding these bulbs is proving 
difficult.

If you're interested, here's some controllers:
http://www.cs.indiana.edu/~willie/lvr.html
http://www.lasertagparts.com/lightbrain/index.htm
http://www.quickar.com/tkit.php?session=Rb0v0Fx5
http://www.trailheadlights.com/

You should look into a 3W Luxeon LED headlight.

I have a luxeon LED flashlight and it is much brigher than any other 
flashlight that I own.. It runs on 4 AA batteries for approx 4 hours.

- Mike


"Bruce W.1" <s...@noDirectEmail.com> wrote in message 
news:X%vwh.5314$z...@newssvr29.news.prodigy.net...
> Bob Masta wrote:
>>
>>
>> Cheap and tiny, but requiring a bit of cobbling:
>> Get a cheap DMM (often on sale at Harbor Freight
>> for under $5).  These have displays about 1/2"
>> high and 2" long.  (Hey. you have to be able to
>> read the display!  half-inch square would be tought
>> unless you had really tiny digits..)  Inside the case
>> is a big rotary range selector switch and a little
>> chip under a black blob.  Just figure out which
>> connections are made for the range you want,
>> hot-wire those and eliminate the switch, and install in the smaller case 
>> of your choice.
>>
>> Oh, the DMMs run on 9V, but they don't draw
>> much juice so you can probably drop the 12V
>> with a simple zener circuit.
>>
>> Best regards,
>>
>>
>> Bob Masta
>>  D A Q A R T A
>> Data AcQuisition And Real-Time Analysis
>>            www.daqarta.com
>> Scope, Spectrum, Spectrogram, Signal Generator
>>     Science with your sound card!
> ===============================================
>
> That's beginning to look like a good option.  I really don't want to get 
> into programming a pic chip.  This is getting pretty complicated anyway. 
> Maybe I'll just fix it at 13.2 volts and call it a day, and take along my 
> mini RS multimeter.
>
> There are some wonderful HID (metal halide) lights on the market but they 
> cost big bucks.
>
> For tail lighting I'm using a Cateye TL-LD1000 which is red LEDs and has 
> its own AA batteries.  This and an amber strobe (12 volts) from All 
> Electronics, this will run off the battery pack (12 alkaline C-cells).
>
> I'm using alkalines because I wouln't always have the ability to charge 
> rechargeables, but you can always buy alkalines.
>
> The headlights, at this time will probably be two 12 volt 10-watt MR16 
> bulbs (one flood, one spot).  Though finding these bulbs is proving 
> difficult.
>
> If you're interested, here's some controllers:
> http://www.cs.indiana.edu/~willie/lvr.html
> http://www.lasertagparts.com/lightbrain/index.htm
> http://www.quickar.com/tkit.php?session=Rb0v0Fx5
> http://www.trailheadlights.com/
>