Chip with simple program for Toy

[David L. Jones]

On Feb 1, 5:45 am, "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.

Less than 1" wide:
http://au.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=9932909
Standard 200mV FSD, just make your own input scaler.

Dave

 

[Bruce W.1]

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.

 

[Jason von Nieda]

Bruce W.1 wrote:

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.

Bruce,

If you need to do voltage monitoring and PWM at the same time, I might
recommend a AVR for the whole job. There might be cheaper/better/faster
ways to do it, but you can get AVR microcontrollers for a few bucks that
have PWM and ADC right on them. Use the ADC and a little resistor
voltage divider to monitor your power.
All the software development tools for AVRs are free, and you can build
a programmer for them out of a parallel printer cable and a pair of wire
cutters

You may be completely familiar with AVRs and microcontrollers, but if
not, feel free to drop me a line at jason@vonnieda.org if you want some
tips.

Jason

 

[Jamie]

David L. Jones wrote:

On Feb 1, 5:45 am, "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.


Less than 1" wide:
http://au.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=9932909
Standard 200mV FSD, just make your own input scaler.

Dave

you got to be kidding me, the price will kill the budget before

you even get started.


--
"I'm never wrong, once i thought i was, but was mistaken"
Real Programmers Do things like this.
http://webpages.charter.net/jamie_5

 

[David L. Jones]

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.

My battery pack (12 C-cells) exceeds its
[14VDC] voltage rating.

No problem, drop the voltage with a regulator

Dave

 

[David L. Jones]

On Feb 1, 10:43 am, Jamie
<jamie_ka1lpa_not_valid_after_ka1l...@charter.net> wrote:

David L. Jones wrote:
On Feb 1, 5:45 am, "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.

Less than 1" wide:
http://au.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=9932909
Standard 200mV FSD, just make your own input scaler.

Dave

you got to be kidding me, the price will kill the budget before
you even get started.

The OP did not specify any budget.
He asked for the smallest panel mount LCD voltmeter. If that's the
best available then he might just have to pay that.

Dave

 

[Michael Black]

"David L. Jones" (altzone@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. 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.

Michael

 

[Peter Bennett]

On Wed, 31 Jan 2007 16:03:16 -0500, "Bruce W.1"
<sorry@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
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca

 

[David L. Jones]

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

 

[Yukio YANO]

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

 

[David L. Jones]

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

 

[pLaNiX]

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.

 

[Martin]

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.

 

[Del Cecchi]

Erik Magnuson wrote:

Paul Keinanen wrote:

On Tue, 30 Jan 2007 11:19:36 +0100, "Michael Weiss"
maerchenprinz@arcor.de> wrote:


Hi all,

I wonder what is curently state-of-the art in serial high-speed
transmission and what are the prevailing data rates? I know about
some SerDes in the gigabit-per-second range but I cannot imagine if
10 Gbps are really a challenge or the applied method or if it's 1
Gbps (or something in between)...?



From the RF design point of view, one should remember that the power
is no longer transmitted with the conductors, but instead propagates
as a field between the conductor and ground plane (or between
conductors in a balanced system). Thus, the dielectric losses of the
PCB or coaxial cable insulation materials will be important, so
ordinary glass fiber boards and PE insulated cables may be
inappropriate at higher frequencies and more expensive materials may
have to be used.


PE is still a pretty good dielectric in the GHz range, but FR-4
substrate starts hurting by the time you gets to a GHz (Del Cecchi made
similar rude noises about FR-4 as well - wonder what he would think of
PVC...). The microwave guys have had a lot of experience with PCB
performance in the GHz range - dielectric loss will have a much worse
effect on a stripline filter than it will on a digital signal.

- Erik

the non teflon stuff isn't too bad if it is nice and foamed. UHF TV
does ok.

--
Del Cecchi
"This post is my own and doesn’t necessarily represent IBM’s positions,
strategies or opinions.”

 

[Erik Magnuson]

Del Cecchi wrote:

Erik Magnuson wrote:

Paul Keinanen wrote:


From the RF design point of view, one should remember that the power
is no longer transmitted with the conductors, but instead propagates
as a field between the conductor and ground plane (or between
conductors in a balanced system). Thus, the dielectric losses of the
PCB or coaxial cable insulation materials will be important, so
ordinary glass fiber boards and PE insulated cables may be
inappropriate at higher frequencies and more expensive materials may
have to be used.



PE is still a pretty good dielectric in the GHz range, but FR-4
substrate starts hurting by the time you gets to a GHz (Del Cecchi
made similar rude noises about FR-4 as well - wonder what he would
think of PVC...). The microwave guys have had a lot of experience with
PCB performance in the GHz range - dielectric loss will have a much
worse effect on a stripline filter than it will on a digital signal.

- Erik


the non teflon stuff isn't too bad if it is nice and foamed. UHF TV
does ok.

AFAIK, the foaming is more to increase inner conductor size and thus
reducing copper losses, than to reduce dielectric losses. I've seen
solid PE cable spec'ed to operate at 10 GHz (e.g. RG-223). Besides,
polytetrafluoroethylene (PTFE aka Teflon) is basically polyethylene with
the hydrogen replaced by fluorine - there may be subtle effects due to
the fluorine being much heavier than hydrogen, but there isn't anything
that would give PTFE a large advantage over PE (other than PTFE doesn't
soften when soldered).

Big problem with Coax much above 10 GHz is that it needs to be small
(0.5 inch Heliax is the largest that will work at 10 GHz per Andrew
catalog) to suppress non-TEM modes and the small size plus skin effect
send attenuation through the roof.

I knew someone at Lockheed Martin who worked on a modulator capable of
working at 100 GHz - an impressive accomplishment - but wondered how it
would have been possible to send a 100 GHz signal more than a few mm via
copper.

- Erik

 

[Paul E. Schoen]

"default" <default@defaulter.net> wrote in message
news:8dvbs212o0ar41i21p591e5bb0gglinhqt@4ax.com...

On Sat, 3 Feb 2007 17:36:05 -0500, "Michael Kennedy"
Mikek400@remthis.comcast.net> wrote:

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

I second that idea. Though I'd probably go with a Cree LED if using
more than one - they don't sell "bin numbers" their LEDs either meet
specification or they don't sell them.

I put 56, 13,000 mcd, white LEDs in an auxiliary light on my
motorcycle and it is very bright - easily enough for a bicycle under
most conditions. In daylight it is more noticeable than the headlight
low beam. Burns 3.4 watts and outshines the 50 watt low beam. Only
cost $9 Beam angle on that is only +/- 10 degrees - so it won't
replace the low beam at night

I have four Cree red LEDs in the tail lamp and it is way overkill . .
I should have used just two. At $8 each Beam angle on those is 120
degrees
--

Yes, LEDs are definitely more efficient. I have designed a current
regulated driver for strings of Cree LEDs. My friend Tony
(www.patcoinc.com) is making a diving flashlight that will have either 7 or
13 of the 3 Watt LEDs (which requires up to about 50 VDC). My circuit
(using a PIC and a boost converter) produces 750 mA from 10-14 VDC, and it
has a low power mode which drives the LEDs at only 100 mA, which is still
plenty bright. The circuit board is only 1" x 2". It also senses low
battery condition and then flashes the LEDs to conserve power and also
provide a warning. I'll be getting boards made soon. All the parts are
maybe $10, and you can reprogram the PIC if you want other features or
different output currents. It has about 90% efficiency. Let me know if you
would like one of the boards for your project or others.

Paul
www.pstech-inc.com

 

[Baron]

john jardine wrote:

"Geronimo Stempovski" <geronimo.stempovski@arcor.de> wrote in
message
news:45d04b34$0$27624$9b4e6d93@newsspool2.arcor-online.net...
I think transmitting high-speed signals is very easy when you have
a 360-degree ground reference, round conductors,
and no other nearby signals like in coaxial cables. My aim is to
design
PCB
tracks as much like a coaxial cable as
possible. Anyone tried this before? Is it possible with regular
FR4,
anyway?
Thanks for your help.

Gero

Had trouble with crosstalk on a mass of video signals. Cured with a
multilayer board where each signal was 'boxed in' by ground plane to
the sides, above and below. Sort of square coax.

I used a similar technique 20 years ago for building high power
dividers.

--
Best Regards:
Baron.

 

[contrex]

On 13 Feb, 05:09, roadrunner_uk_98 <roadrunner_uk...@yahoo.com> wrote:
What the hell are you on about?

 

On 14 Feb, 09:42, "contrex" <mike.j.har...@gmail.com> wrote:

On 13 Feb, 05:09, roadrunner_uk_98 <roadrunner_uk...@yahoo.com> wrote:



What the hell are you on about?

I think it's gone to the wrong group but read it as a teachers request
for some science based questions to be used as a resource at the (UK)
'Science museum', during one of their night time, schoolkids, 'camp
in' sessions.
I'm undoubtably wrong but the fun is in the chase.

 

[Michael Black]

(john@jjdesigns.fsnet.co.uk) writes:

On 14 Feb, 09:42, "contrex" <mike.j.har...@gmail.com> wrote:
On 13 Feb, 05:09, roadrunner_uk_98 <roadrunner_uk...@yahoo.com> wrote:



What the hell are you on about?

I think it's gone to the wrong group but read it as a teachers request
for some science based questions to be used as a resource at the (UK)
'Science museum', during one of their night time, schoolkids, 'camp
in' sessions.
I'm undoubtably wrong but the fun is in the chase.


Wasn't there a movie released a few weeks ago with that title?

So I read the post as someone wanting a bootleg copy of the movie,
and they posted here in the same way people sometimes post in the
sci.electronics.* hierarchy asking consumer type questions about specific
consumer electronics. Ie, they think "electronics" is their gadgetry
they consume, rather than what goes on inside.

Michael