Most efficient way to get 1.5 volts from 3.7 volts or less?

I have a digital height gauge that eats batteries. Not a cheap Chinese
made one, but a fairly high quality Japanese made one. It uses one
SR44 battery. For some reason it has started using batteries much
faster than it used to. I have tried several different brands of
batteries from several different sources and they all seem to last
about the same. Because of the bulk of the sliding portion of the
gauge I could easily attach a lithium coin cell holder and associated
voltage dropping circuitry. Even a couple AA size batteries. I did try
a typical alkaline AA cell but it didn't last much longer than a
button cell. I think this is because the display starts flashing when
the battey voltage drops to 1.45 volts or less. So what would be best
for the longest battery life?
Thanks,
Eric

 

[Jim Thompson]

On Fri, 22 Sep 2017 11:15:28 -0700, etpm@whidbey.com wrote:

I have a digital height gauge that eats batteries. Not a cheap Chinese
made one, but a fairly high quality Japanese made one. It uses one
SR44 battery. For some reason it has started using batteries much
faster than it used to. I have tried several different brands of
batteries from several different sources and they all seem to last
about the same. Because of the bulk of the sliding portion of the
gauge I could easily attach a lithium coin cell holder and associated
voltage dropping circuitry. Even a couple AA size batteries. I did try
a typical alkaline AA cell but it didn't last much longer than a
button cell. I think this is because the display starts flashing when
the battey voltage drops to 1.45 volts or less. So what would be best
for the longest battery life?
Thanks,
Eric

Take the battery out when not using the gauge. I have a set of
calipers that "eat" batteries like that, because it's always drawing
some current while waiting to "turn-on" when I turn the dial.

...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| STV, Queen Creek, AZ 85142 Skype: skypeanalog | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I'm looking for work... see my website.

Thinking outside the box...producing elegant & economic solutions.

 

Though that would save batteries it is not practical for a tool that
gets used often, as this one does. Plus the fact that 4 screws must be
removed to change the battery.
Eric
On Fri, 22 Sep 2017 12:24:28 -0700, Jim Thompson
<To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Fri, 22 Sep 2017 11:15:28 -0700, etpm@whidbey.com wrote:

I have a digital height gauge that eats batteries. Not a cheap Chinese
made one, but a fairly high quality Japanese made one. It uses one
SR44 battery. For some reason it has started using batteries much
faster than it used to. I have tried several different brands of
batteries from several different sources and they all seem to last
about the same. Because of the bulk of the sliding portion of the
gauge I could easily attach a lithium coin cell holder and associated
voltage dropping circuitry. Even a couple AA size batteries. I did try
a typical alkaline AA cell but it didn't last much longer than a
button cell. I think this is because the display starts flashing when
the battey voltage drops to 1.45 volts or less. So what would be best
for the longest battery life?
Thanks,
Eric

Take the battery out when not using the gauge. I have a set of
calipers that "eat" batteries like that, because it's always drawing
some current while waiting to "turn-on" when I turn the dial.

...Jim Thompson

 

[Jim Thompson]

On Fri, 22 Sep 2017 13:11:24 -0700, etpm@whidbey.com wrote:

Though that would save batteries it is not practical for a tool that
gets used often, as this one does. Plus the fact that 4 screws must be
removed to change the battery.
Eric
On Fri, 22 Sep 2017 12:24:28 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Fri, 22 Sep 2017 11:15:28 -0700, etpm@whidbey.com wrote:

I have a digital height gauge that eats batteries. Not a cheap Chinese
made one, but a fairly high quality Japanese made one. It uses one
SR44 battery. For some reason it has started using batteries much
faster than it used to. I have tried several different brands of
batteries from several different sources and they all seem to last
about the same. Because of the bulk of the sliding portion of the
gauge I could easily attach a lithium coin cell holder and associated
voltage dropping circuitry. Even a couple AA size batteries. I did try
a typical alkaline AA cell but it didn't last much longer than a
button cell. I think this is because the display starts flashing when
the battey voltage drops to 1.45 volts or less. So what would be best
for the longest battery life?
Thanks,
Eric

Take the battery out when not using the gauge. I have a set of
calipers that "eat" batteries like that, because it's always drawing
some current while waiting to "turn-on" when I turn the dial.

...Jim Thompson

OK. If you have room to attach a battery holder, why not just add a
switch?

...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| STV, Queen Creek, AZ 85142 Skype: skypeanalog | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I'm looking for work... see my website.

Thinking outside the box...producing elegant & economic solutions.

 

[whit3rd]

On Friday, September 22, 2017 at 11:14:58 AM UTC-7, et...@whidbey.com wrote:

I have a digital height gauge that eats batteries. Not a cheap Chinese
made one, but a fairly high quality Japanese made one. It uses one
SR44 battery.
button cell. I think this is because the display starts flashing when
the battey voltage drops to 1.45 volts or less. So what would be best
for the longest battery life?

There's a silver-oxide battery type that's drop-in compatible with LR44, designated
variously. Panasonic says LR44 is good for 120 mAh, sized 11.5mm diam, 5.1mm high,
and the similar silver-oxide SR44 is 180 mAh, 11.6mm diam, 5.4mm high.

Other names for the silver-oxide are V76, AG13... and the names get
applied loosely by online merchants of any-old-thing-that-might-fit.

It also might be possible to substitute a supercapacitor, there's some modest-sized ones
that could take several minutes to droop from 1.8V to 1.0... you'd have to
recharge it after a few minutes, but a charge stand or holster would't be TOO
difficult for someone with machine tools

 

[whit3rd]

Don't know if it's useful for you, but the cellphones that use low-voltage
memory have opened a market for 1.5V regulator chips (that's the good news)
which are almost always tiny (that's the bad news).

NCP170 is typical
<http://www.onsemi.com/pub/Collateral/NCP170-D.PDF>

 

[Cursitor Doom]

On Fri, 22 Sep 2017 13:19:06 -0700, Jim Thompson wrote:

OK. If you have room to attach a battery holder, why not just add a
switch?

I have the same problem with mine, too. It's very common. You'd have
thought the manufacturers would fit a switch in the first place. You
could still have the auto-on feature but just have the switch disable it
between sessions.





--
This message may be freely reproduced without limit or charge only via
the Usenet protocol. Reproduction in whole or part through other
protocols, whether for profit or not, is conditional upon a charge of
GBP10.00 per reproduction. Publication in this manner via non-Usenet
protocols constitutes acceptance of this condition.

 

On Fri, 22 Sep 2017 13:19:06 -0700, Jim Thompson
<To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Fri, 22 Sep 2017 13:11:24 -0700, etpm@whidbey.com wrote:

Though that would save batteries it is not practical for a tool that
gets used often, as this one does. Plus the fact that 4 screws must be
removed to change the battery.
Eric
On Fri, 22 Sep 2017 12:24:28 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Fri, 22 Sep 2017 11:15:28 -0700, etpm@whidbey.com wrote:

I have a digital height gauge that eats batteries. Not a cheap Chinese
made one, but a fairly high quality Japanese made one. It uses one
SR44 battery. For some reason it has started using batteries much
faster than it used to. I have tried several different brands of
batteries from several different sources and they all seem to last
about the same. Because of the bulk of the sliding portion of the
gauge I could easily attach a lithium coin cell holder and associated
voltage dropping circuitry. Even a couple AA size batteries. I did try
a typical alkaline AA cell but it didn't last much longer than a
button cell. I think this is because the display starts flashing when
the battey voltage drops to 1.45 volts or less. So what would be best
for the longest battery life?
Thanks,
Eric

Take the battery out when not using the gauge. I have a set of
calipers that "eat" batteries like that, because it's always drawing
some current while waiting to "turn-on" when I turn the dial.

...Jim Thompson

OK. If you have room to attach a battery holder, why not just add a
switch?

...Jim Thompson

Greetings Jim,
Every time I turn off the power I would then need to re-zero the
gauge. This takes time and is something I don't want to do every time
I use the gauge, which is several times a day. I could turn it off at
night I suppose but then I would need to remember that.
Eric

 

On Fri, 22 Sep 2017 15:58:34 -0700 (PDT), whit3rd <whit3rd@gmail.com>
wrote:

Don't know if it's useful for you, but the cellphones that use low-voltage
memory have opened a market for 1.5V regulator chips (that's the good news)
which are almost always tiny (that's the bad news).

NCP170 is typical
http://www.onsemi.com/pub/Collateral/NCP170-D.PDF

Thanks, that chip or one similar looks like just what I need.
Eric

 

[rickman]

etpm@whidbey.com wrote on 9/23/2017 12:17 PM:

On Fri, 22 Sep 2017 13:19:06 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Fri, 22 Sep 2017 13:11:24 -0700, etpm@whidbey.com wrote:

Though that would save batteries it is not practical for a tool that
gets used often, as this one does. Plus the fact that 4 screws must be
removed to change the battery.
Eric
On Fri, 22 Sep 2017 12:24:28 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Fri, 22 Sep 2017 11:15:28 -0700, etpm@whidbey.com wrote:

I have a digital height gauge that eats batteries. Not a cheap Chinese
made one, but a fairly high quality Japanese made one. It uses one
SR44 battery. For some reason it has started using batteries much
faster than it used to. I have tried several different brands of
batteries from several different sources and they all seem to last
about the same. Because of the bulk of the sliding portion of the
gauge I could easily attach a lithium coin cell holder and associated
voltage dropping circuitry. Even a couple AA size batteries. I did try
a typical alkaline AA cell but it didn't last much longer than a
button cell. I think this is because the display starts flashing when
the battey voltage drops to 1.45 volts or less. So what would be best
for the longest battery life?
Thanks,
Eric

Take the battery out when not using the gauge. I have a set of
calipers that "eat" batteries like that, because it's always drawing
some current while waiting to "turn-on" when I turn the dial.

...Jim Thompson

OK. If you have room to attach a battery holder, why not just add a
switch?

...Jim Thompson
Greetings Jim,
Every time I turn off the power I would then need to re-zero the
gauge. This takes time and is something I don't want to do every time
I use the gauge, which is several times a day. I could turn it off at
night I suppose but then I would need to remember that.
Eric

I think that is the only practical solution. I got tired of replacing the
battery in my digital caliper, so I started removing it since I sometimes go
a month or more without using it. Then I started using my old dial caliper
and the digital hasn't been out of the box for a long time.

Switching to a slightly larger cell isn't going to do much for you. If an
AA cell doesn't cut it I'm a bit at a loss. Cutting off at 1.45 volts says
to me your gauge is dodgy. If you want to work around that with a
regulator, you can get very small switching devices that will give you
optimum efficiency or a small linear will allow you to use a lithium cell.
Otherwise maybe a solar cell would do the job?

--

Rick C

Viewed the eclipse at Wintercrest Farms,
on the centerline of totality since 1998

 

[Bob Engelhardt]

If I was going to buck regulate, I'd use 9v battery to get significant
watt-hours and a $0.99 from-China regulator. No screwing around with a
PCB carrier.

 

[Jasen Betts]

On 2017-09-22, etpm@whidbey.com <etpm@whidbey.com> wrote:

I have a digital height gauge that eats batteries. Not a cheap Chinese
made one, but a fairly high quality Japanese made one. It uses one
SR44 battery. For some reason it has started using batteries much
faster than it used to.

Could be there's moisture inside your gauge, dry it out!

--
This email has not been checked by half-arsed antivirus software

 

On 24 Sep 2017 01:08:30 GMT, Jasen Betts <jasen@xnet.co.nz> wrote:

On 2017-09-22, etpm@whidbey.com <etpm@whidbey.com> wrote:
I have a digital height gauge that eats batteries. Not a cheap Chinese
made one, but a fairly high quality Japanese made one. It uses one
SR44 battery. For some reason it has started using batteries much
faster than it used to.

Could be there's moisture inside your gauge, dry it out!
No moisture. No corrosion even visible with magnification.

 

[default]

On Sun, 24 Sep 2017 11:56:03 -0700, etpm@whidbey.com wrote:

On 24 Sep 2017 01:08:30 GMT, Jasen Betts <jasen@xnet.co.nz> wrote:

On 2017-09-22, etpm@whidbey.com <etpm@whidbey.com> wrote:
I have a digital height gauge that eats batteries. Not a cheap Chinese
made one, but a fairly high quality Japanese made one. It uses one
SR44 battery. For some reason it has started using batteries much
faster than it used to.

Could be there's moisture inside your gauge, dry it out!
No moisture. No corrosion even visible with magnification.

You'd be surprised... With surface mount parts close together, low
current high impedance circuits, a little moisture on some surface
dirt is all it takes. To be safe(er) the boards should be baked for a
time then coated with a suitable varnish while still hot and dry -
then (if the pcb quality is up to snuff) you stand a pretty good
chance of it working without phantom circuit losses.

 

On Sun, 24 Sep 2017 18:15:16 -0400, default <default@defaulter.net>
wrote:

On Sun, 24 Sep 2017 11:56:03 -0700, etpm@whidbey.com wrote:

On 24 Sep 2017 01:08:30 GMT, Jasen Betts <jasen@xnet.co.nz> wrote:

On 2017-09-22, etpm@whidbey.com <etpm@whidbey.com> wrote:
I have a digital height gauge that eats batteries. Not a cheap Chinese
made one, but a fairly high quality Japanese made one. It uses one
SR44 battery. For some reason it has started using batteries much
faster than it used to.

Could be there's moisture inside your gauge, dry it out!
No moisture. No corrosion even visible with magnification.

You'd be surprised... With surface mount parts close together, low
current high impedance circuits, a little moisture on some surface
dirt is all it takes. To be safe(er) the boards should be baked for a
time then coated with a suitable varnish while still hot and dry -
then (if the pcb quality is up to snuff) you stand a pretty good
chance of it working without phantom circuit losses.

I don't even know how I would go about coating anything without
ruining the read head. The read head is some sort of capacitive
device. All the circuitry is located on one side of the circuit board
that comprises the read head. There are a whole bunch of tiny holes
that go through the circuit board. All of the capacitive type encoders
are made the same way.
So all the cheap electronic calipers look the same inside. Sylvac
invented the device (if memory serves correctly) and more than one
Japanese company made encoders under license. Mitutoyo was one. But
now the patents have expired or have been pirated so you see these
things everywhere.
Any significant moisture will cause the read head to malfunction so
I don't know if moisture is a problem. Thanks for the suggestion
anyway.
Eric

 

[Phil Hobbs]

On 09/24/2017 06:15 PM, default wrote:

On Sun, 24 Sep 2017 11:56:03 -0700, etpm@whidbey.com wrote:

On 24 Sep 2017 01:08:30 GMT, Jasen Betts <jasen@xnet.co.nz> wrote:

On 2017-09-22, etpm@whidbey.com <etpm@whidbey.com> wrote:
I have a digital height gauge that eats batteries. Not a cheap Chinese
made one, but a fairly high quality Japanese made one. It uses one
SR44 battery. For some reason it has started using batteries much
faster than it used to.

Could be there's moisture inside your gauge, dry it out!
No moisture. No corrosion even visible with magnification.

You'd be surprised... With surface mount parts close together, low
current high impedance circuits, a little moisture on some surface
dirt is all it takes. To be safe(er) the boards should be baked for a
time then coated with a suitable varnish while still hot and dry -
then (if the pcb quality is up to snuff) you stand a pretty good
chance of it working without phantom circuit losses.

Well, for sufficiently small values of "eats batteries". I'd vote for a
damaged FET on an IC input someplace, perhaps due to ESD.

I just had the catch diode come loose on a SMPS proto, which caused the
output voltage of the regulator to go from 6.2V to 4.5V. Took me awhile
to figure out that the CMOS switcher chip was toast. It was an
AOZ1282-1--quite a nice chip actually, as long as you don't blow it up.

Sort of a 1-MHz CMOS version of the LM2594 but more efficient and with a
much more convenient enable pin, so that you can implement UVLO with
just a zener and a resistor to ground.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net

 

[George Herold]

On Friday, September 22, 2017 at 2:14:58 PM UTC-4, et...@whidbey.com wrote:

I have a digital height gauge that eats batteries. Not a cheap Chinese
made one, but a fairly high quality Japanese made one. It uses one
SR44 battery. For some reason it has started using batteries much
faster than it used to. I have tried several different brands of
batteries from several different sources and they all seem to last
about the same. Because of the bulk of the sliding portion of the
gauge I could easily attach a lithium coin cell holder and associated
voltage dropping circuitry. Even a couple AA size batteries. I did try
a typical alkaline AA cell but it didn't last much longer than a
button cell. I think this is because the display starts flashing when
the battey voltage drops to 1.45 volts or less. So what would be best
for the longest battery life?
Thanks,
Eric

Eric, I'd troll digikey looking for DC-DC converters.

https://www.digikey.com/products/en/power-supplies-board-mount/dc-dc-converters/922?k=&pkeyword=&pv1989=0&FV=15c0002%2C17d40027%2C17d40030%2C17d40034%2C17d4020b%2Cffe0039a%2C1c0011%2C1c0002%2C1c0003%2C1c0006&mnonly=0&ColumnSort=0&page=1&stock=1&quantity=0&ptm=0&fid=0&pageSize=100

(A long link.. sorry)

George H.

 

[rickman]

etpm@whidbey.com wrote on 9/22/2017 2:15 PM:

I have a digital height gauge that eats batteries. Not a cheap Chinese
made one, but a fairly high quality Japanese made one. It uses one
SR44 battery. For some reason it has started using batteries much
faster than it used to. I have tried several different brands of
batteries from several different sources and they all seem to last
about the same. Because of the bulk of the sliding portion of the
gauge I could easily attach a lithium coin cell holder and associated
voltage dropping circuitry. Even a couple AA size batteries. I did try
a typical alkaline AA cell but it didn't last much longer than a
button cell. I think this is because the display starts flashing when
the battey voltage drops to 1.45 volts or less. So what would be best
for the longest battery life?
Thanks,
Eric

There was a Kickstarter project for a clip on switching converter for AA
cells that would provide a constant output voltage as the battery drained.
It was barely larger than the AA cell so could be used in the same socket
designed for the AA cell. The question is what voltage it would put out
since your device seems to be abnormally sensitive to the voltage.

--

Rick C

Viewed the eclipse at Wintercrest Farms,
on the centerline of totality since 1998

 

On Tue, 26 Sep 2017 17:17:45 -0400, rickman <gnuarm@gmail.com> wrote:

etpm@whidbey.com wrote on 9/22/2017 2:15 PM:
I have a digital height gauge that eats batteries. Not a cheap Chinese
made one, but a fairly high quality Japanese made one. It uses one
SR44 battery. For some reason it has started using batteries much
faster than it used to. I have tried several different brands of
batteries from several different sources and they all seem to last
about the same. Because of the bulk of the sliding portion of the
gauge I could easily attach a lithium coin cell holder and associated
voltage dropping circuitry. Even a couple AA size batteries. I did try
a typical alkaline AA cell but it didn't last much longer than a
button cell. I think this is because the display starts flashing when
the battey voltage drops to 1.45 volts or less. So what would be best
for the longest battery life?
Thanks,
Eric

There was a Kickstarter project for a clip on switching converter for AA
cells that would provide a constant output voltage as the battery drained.
It was barely larger than the AA cell so could be used in the same socket
designed for the AA cell. The question is what voltage it would put out
since your device seems to be abnormally sensitive to the voltage.

Yeah, I'm not certain how high it can go. I know 5.5 volts is OK
because that's what the silver oxide cells measure when new. It's too
bad the display flashes when the voltage drops to 4.5.
Eric

 

[rickman]

etpm@whidbey.com wrote on 9/26/2017 5:41 PM:

On Tue, 26 Sep 2017 17:17:45 -0400, rickman <gnuarm@gmail.com> wrote:

etpm@whidbey.com wrote on 9/22/2017 2:15 PM:
I have a digital height gauge that eats batteries. Not a cheap Chinese
made one, but a fairly high quality Japanese made one. It uses one
SR44 battery. For some reason it has started using batteries much
faster than it used to. I have tried several different brands of
batteries from several different sources and they all seem to last
about the same. Because of the bulk of the sliding portion of the
gauge I could easily attach a lithium coin cell holder and associated
voltage dropping circuitry. Even a couple AA size batteries. I did try
a typical alkaline AA cell but it didn't last much longer than a
button cell. I think this is because the display starts flashing when
the battey voltage drops to 1.45 volts or less. So what would be best
for the longest battery life?
Thanks,
Eric

There was a Kickstarter project for a clip on switching converter for AA
cells that would provide a constant output voltage as the battery drained.
It was barely larger than the AA cell so could be used in the same socket
designed for the AA cell. The question is what voltage it would put out
since your device seems to be abnormally sensitive to the voltage.
Yeah, I'm not certain how high it can go. I know 5.5 volts is OK
because that's what the silver oxide cells measure when new. It's too
bad the display flashes when the voltage drops to 4.5.
Eric

I assume those are typos and you actually mean 1.55 or 1.5 volts and 1.45
volts?

--

Rick C

Viewed the eclipse at Wintercrest Farms,
on the centerline of totality since 1998