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I should proofread my posts better. 1.55 volts and 1.45 are indeed theetpm@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?
Greetings George,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.
On Tue, 26 Sep 2017 08:28:44 -0700 (PDT), George Herold
gherold@teachspin.com> wrote:
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.
Greetings George,
I looked and found a couple with apprpriate specs except for the
miniscule size and the location of the solder pads. I did see an
evaluation board described though. I still need to see if one is
available and cheap enough. I also need to figure out if the noise
coming from a DC-DC converter will upset the electronics in my gauge.
Not sure how to do that yet.
Eric
On Tue, 26 Sep 2017 08:28:44 -0700 (PDT), George Herold
gherold@teachspin.com> wrote:
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.
Greetings George,
I looked and found a couple with apprpriate specs except for the
miniscule size and the location of the solder pads. I did see an
evaluation board described though. I still need to see if one is
available and cheap enough. I also need to figure out if the noise
coming from a DC-DC converter will upset the electronics in my gauge.
Not sure how to do that yet.
Eric
... I still need to see if one is
available and cheap enough. I also need to figure out if the noise
coming from a DC-DC converter will upset the electronics in my gauge.
Does cost matter? (As long as less than ~$20 or something.)
(It's going to take you at least an hour to f-around and get it working.)
On Wednesday, September 27, 2017 at 10:41:26 AM UTC-7, George Herold wrote:
On Wednesday, September 27, 2017 at 12:01:40 PM UTC-4, et...@whidbey.com wrote:
[about DC/DC converters for battery adaptation]
... I still need to see if one is
available and cheap enough. I also need to figure out if the noise
coming from a DC-DC converter will upset the electronics in my gauge.
Does cost matter? (As long as less than ~$20 or something.)
(It's going to take you at least an hour to f-around and get it working.)
Mainly, DC/DC converters aren't as energy-stingy as you'd want.
For low quiescent drain, in the absence of a switch, the linear regulators
win (and some have an 'enable' line, to take a switch).
If the threshold is "$20 or something", bear in mind that DigiKey sells
fifty A76 cells (one of the LR44 variant labels, from Energizer) for $21.
If you could replace the 'takes four screws' fitting with a bayonet-mount,
would that help?
If a solar cell could be cemented on, would normal shop lighting
be enough to get readings?
On Wednesday, September 27, 2017 at 10:41:26 AM UTC-7, George Herold wrote:
On Wednesday, September 27, 2017 at 12:01:40 PM UTC-4, et...@whidbey.com wrote:
[about DC/DC converters for battery adaptation]
... I still need to see if one is
available and cheap enough. I also need to figure out if the noise
coming from a DC-DC converter will upset the electronics in my gauge.
Does cost matter? (As long as less than ~$20 or something.)
(It's going to take you at least an hour to f-around and get it working.)
Mainly, DC/DC converters aren't as energy-stingy as you'd want.
For low quiescent drain, in the absence of a switch, the linear regulators
win (and some have an 'enable' line, to take a switch).
If the threshold is "$20 or something", bear in mind that DigiKey sells
fifty A76 cells (one of the LR44 variant labels, from Energizer) for $21.
If you could replace the 'takes four screws' fitting with a bayonet-mount,
would that help?
If a solar cell could be cemented on, would normal shop lighting
be enough to get readings?
On Wed, 27 Sep 2017 15:35:53 -0700 (PDT), whit3rd <whit3rd@gmail.com
wrote:
If a solar cell could be cemented on, would normal shop lighting
be enough to get readings?
Adding a different mounting system for the cover would not be very
easy. I had thought about solar cells in the past but forgot about
them. Can a solar cell be paralleled with a silver oxide button cell
without causing the cell to leak? Or an LR44 alkaline cell?