Buck step down convertor uses a lot of power?

[Winfield Hill]

AK wrote...

On Monday, April 29, 2019 at 2:59:06 PM UTC-5, Winfield Hill wrote:
bloggs.fredbloggs.fred@gmail.com wrote...

Looks like that datasheet on the ADP5300 is somewhat
deceptive. In the details they distinguish between
an IQ_HYS and IQ_PWM.

The low-power hsyteretic control works to 50mA, the
high-power low-ripple PWM control is for up to 500mA.

I fully charged battery up.
In a day, it dropped from 12.6 -> 12.4 volts.
I am happy with that. If it lasts a year,
I will be happy.

If it drops 0.2V/day, it'll drop 6V in 30 days, and
it won't last a year. How about you connect up your
multimeter and find out exactly how much current
your clock takes? If it's too low to see easily,
set the meter to 200mV and measure across a resistor.


--
Thanks,
- Win

 

[AK]

On Monday, April 29, 2019 at 4:17:30 PM UTC-5, Winfield Hill wrote:

AK wrote...

On Monday, April 29, 2019 at 2:59:06 PM UTC-5, Winfield Hill wrote:
bloggs.fredbloggs.fred@gmail.com wrote...

Looks like that datasheet on the ADP5300 is somewhat
deceptive. In the details they distinguish between
an IQ_HYS and IQ_PWM.

The low-power hsyteretic control works to 50mA, the
high-power low-ripple PWM control is for up to 500mA.

I fully charged battery up.
In a day, it dropped from 12.6 -> 12.4 volts.
I am happy with that. If it lasts a year,
I will be happy.

If it drops 0.2V/day, it'll drop 6V in 30 days, and
it won't last a year. How about you connect up your
multimeter and find out exactly how much current
your clock takes? If it's too low to see easily,
set the meter to 200mV and measure across a resistor.


--
Thanks,
- Win

9.6 milliamps

Andy

 

[Martin Brown]

On 30/04/2019 00:10, AK wrote:

On Monday, April 29, 2019 at 4:17:30 PM UTC-5, Winfield Hill wrote:
AK wrote...


I fully charged battery up.
In a day, it dropped from 12.6 -> 12.4 volts.
I am happy with that. If it lasts a year,
I will be happy.

If it drops 0.2V/day, it'll drop 6V in 30 days, and
it won't last a year. How about you connect up your
multimeter and find out exactly how much current
your clock takes? If it's too low to see easily,
set the meter to 200mV and measure across a resistor.


--
Thanks,
- Win

9.6 milliamps

Is that how much current your clock draws or how much the contraption
you are powering your clock from is drawing? The typical current
consumption for an LCD atomic clock is somewhere around 100uA or less.

They should last about two years on a fresh pair of AA batteries!

--
Regards,
Martin Brown

 

On Tuesday, 30 April 2019 00:10:27 UTC+1, AK wrote:

On Monday, April 29, 2019 at 4:17:30 PM UTC-5, Winfield Hill wrote:
AK wrote...
On Monday, April 29, 2019 at 2:59:06 PM UTC-5, Winfield Hill wrote:

I fully charged battery up.
In a day, it dropped from 12.6 -> 12.4 volts.
I am happy with that. If it lasts a year,
I will be happy.

If it drops 0.2V/day, it'll drop 6V in 30 days, and
it won't last a year. How about you connect up your
multimeter and find out exactly how much current
your clock takes? If it's too low to see easily,
set the meter to 200mV and measure across a resistor.

9.6 milliamps

Andy

If you used a R&Z supply consuming 12mA, that would eat
12mA x 24 = 288mAh/day so would run about 4 days per Ah of battery capacity.
Of course discharging the battery below 50% will hasten its demise.
A suitable switched mode regulator should get several times that long, but it still doesn't sound like it would survive the year. Lead acids just aren't a good choice for clocks.


NT

 

[AK]

On Tuesday, April 30, 2019 at 7:49:33 AM UTC-5, tabb...@gmail.com wrote:

On Tuesday, 30 April 2019 00:10:27 UTC+1, AK wrote:
On Monday, April 29, 2019 at 4:17:30 PM UTC-5, Winfield Hill wrote:
AK wrote...
On Monday, April 29, 2019 at 2:59:06 PM UTC-5, Winfield Hill wrote:

I fully charged battery up.
In a day, it dropped from 12.6 -> 12.4 volts.
I am happy with that. If it lasts a year,
I will be happy.

If it drops 0.2V/day, it'll drop 6V in 30 days, and
it won't last a year. How about you connect up your
multimeter and find out exactly how much current
your clock takes? If it's too low to see easily,
set the meter to 200mV and measure across a resistor.

9.6 milliamps

Andy

If you used a R&Z supply consuming 12mA, that would eat
12mA x 24 = 288mAh/day so would run about 4 days per Ah of battery capacity.
Of course discharging the battery below 50% will hasten its demise.
A suitable switched mode regulator should get several times that long, but it still doesn't sound like it would survive the year. Lead acids just aren't a good choice for clocks.


NT

Thanks. I will probably go back to the AA source.

Andy

 

[AK]

On Tuesday, April 30, 2019 at 4:51:05 AM UTC-5, Martin Brown wrote:

On 30/04/2019 00:10, AK wrote:
On Monday, April 29, 2019 at 4:17:30 PM UTC-5, Winfield Hill wrote:
AK wrote...


I fully charged battery up.
In a day, it dropped from 12.6 -> 12.4 volts.
I am happy with that. If it lasts a year,
I will be happy.

If it drops 0.2V/day, it'll drop 6V in 30 days, and
it won't last a year. How about you connect up your
multimeter and find out exactly how much current
your clock takes? If it's too low to see easily,
set the meter to 200mV and measure across a resistor.


--
Thanks,
- Win

9.6 milliamps

Is that how much current your clock draws or how much the contraption
you are powering your clock from is drawing? The typical current
consumption for an LCD atomic clock is somewhere around 100uA or less.

They should last about two years on a fresh pair of AA batteries!

--
Regards,
Martin Brown

Comsumption of the clock. And it's a custom contraption.



The clock loses accuracy if voltage gets below 2.9.

As you can see here, the clock has a large LED display.

"https://www.dropbox.com/s/4khc3m775ptl6n2/20190430_165220.jpg?dl=0"

It has to draw a whole lot more than 100 ua.

 

[Martin Brown]

On 30/04/2019 22:55, AK wrote:

On Tuesday, April 30, 2019 at 4:51:05 AM UTC-5, Martin Brown wrote:
On 30/04/2019 00:10, AK wrote:
On Monday, April 29, 2019 at 4:17:30 PM UTC-5, Winfield Hill wrote:
AK wrote...


I fully charged battery up.
In a day, it dropped from 12.6 -> 12.4 volts.
I am happy with that. If it lasts a year,
I will be happy.

If it drops 0.2V/day, it'll drop 6V in 30 days, and
it won't last a year. How about you connect up your
multimeter and find out exactly how much current
your clock takes? If it's too low to see easily,
set the meter to 200mV and measure across a resistor.


--
Thanks,
- Win

9.6 milliamps

Is that how much current your clock draws or how much the contraption
you are powering your clock from is drawing? The typical current
consumption for an LCD atomic clock is somewhere around 100uA or less.

They should last about two years on a fresh pair of AA batteries!

--
Regards,
Martin Brown

Comsumption of the clock. And it's a custom contraption.

It looks like a fairly standard large display LCD unit to me. You should
be able to find one that will last a couple of years on a pair of AA
cells. Some will even support external temperature sensors as well.

The clock loses accuracy if voltage gets below 2.9.

??? Its an atomic clock - it should reset itself daily if it drifts even
slightly. A quartz xtal clock will typically be good to a few tens of
seconds a month drift disciplined by an off the air MSF signal it will
stay within fractions of a second. Mine all keep good time even on low
battery but the display eventually becomes too low contrast to read!

As you can see here, the clock has a large LED display.

"https://www.dropbox.com/s/4khc3m775ptl6n2/20190430_165220.jpg?dl=0"

That is an LCD display. It really shouldn't draw that much current
unless you have the backlight stuck on permanently.

It has to draw a whole lot more than 100 ua.

It really shouldn't.

--
Regards,
Martin Brown

 

[Jasen Betts]

On 2019-04-30, AK <scientist77017@gmail.com> wrote:

The clock loses accuracy if voltage gets below 2.9.

For dry cell power it should work down to 1V per cell
will it run from 5V? can you give it 3 cells in series?

As you can see here, the clock has a large LED display.

"https://www.dropbox.com/s/4khc3m775ptl6n2/20190430_165220.jpg?dl=0"

It has to draw a whole lot more than 100 ua.

For an non-matrix LCD display with a slow update rate 0.1 mA sounds fine

--
When I tried casting out nines I made a hash of it.

 

[Rob]

AK <scientist77017@gmail.com> wrote:

I wanted to use the large battery since I am not using it. It was formerly used as a UPC when I upgraded it.

I thought with it's much larger capacity than aa or 18650, it would last for a long time.

Ok but that was a miscalculation, due to the down converter.
When you can find another converter (see other replies) that uses less
current ("quiescent current" is what you look for) it could be an option
to use that battery. Else I would go for a new battery with the correct
voltage and more capacity, like a pair of D alkaline cells or a larger
Lithium cell.

 

On Tuesday, April 30, 2019 at 5:51:05 AM UTC-4, Martin Brown wrote:

On 30/04/2019 00:10, AK wrote:
On Monday, April 29, 2019 at 4:17:30 PM UTC-5, Winfield Hill wrote:
AK wrote...


I fully charged battery up.
In a day, it dropped from 12.6 -> 12.4 volts.
I am happy with that. If it lasts a year,
I will be happy.

If it drops 0.2V/day, it'll drop 6V in 30 days, and
it won't last a year. How about you connect up your
multimeter and find out exactly how much current
your clock takes? If it's too low to see easily,
set the meter to 200mV and measure across a resistor.


--
Thanks,
- Win

9.6 milliamps

Is that how much current your clock draws or how much the contraption
you are powering your clock from is drawing? The typical current
consumption for an LCD atomic clock is somewhere around 100uA or less.

They should last about two years on a fresh pair of AA batteries!

Funny, every one I've had used a single AA battery. Can't say what the current is but I only expect them to run a year. Never actually checked.

--

Rick C.

- Get a 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209

 

[Martin Brown]

On 02/05/2019 01:15, gnuarm.deletethisbit@gmail.com wrote:

On Tuesday, April 30, 2019 at 5:51:05 AM UTC-4, Martin Brown wrote:
On 30/04/2019 00:10, AK wrote:
On Monday, April 29, 2019 at 4:17:30 PM UTC-5, Winfield Hill
wrote:
AK wrote...


I fully charged battery up. In a day, it dropped from 12.6 -
12.4 volts. I am happy with that. If it lasts a year, I will
be happy.

If it drops 0.2V/day, it'll drop 6V in 30 days, and it won't
last a year. How about you connect up your multimeter and find
out exactly how much current your clock takes? If it's too low
to see easily, set the meter to 200mV and measure across a
resistor.

9.6 milliamps

Is that how much current your clock draws or how much the
contraption you are powering your clock from is drawing? The
typical current consumption for an LCD atomic clock is somewhere
around 100uA or less.

They should last about two years on a fresh pair of AA batteries!

Funny, every one I've had used a single AA battery. Can't say what
the current is but I only expect them to run a year. Never actually
checked.

It is obviously possible to run them on a single cell just like LCD
watches do but many of them do use a pair of AA batteries. The important
point here is that no MSF clock of modern design should be drawing 10mA.

LCDs can be a bit dim on a single cell voltage unless you draw a bit
more current to run them from a voltage doubler.

The first one I ever built in the 1970's using an NE567 tone decoder did
draw ~10mA but using discrete components and it had no display at all.

These days almost all of them are a standard receiver module, decode
display module and an LCD display. The only clever bit is how they
discipline the local crystal oscillator and so how often they have to
turn on the receiver. Cheap and cheerful ones run it continuously. eg.

https://www.mas-oy.com/wp-content/uploads/2016/05/DAEV6181B1COB.pdf

Takes about 50uA and the display module is about the same.

The really smart ones tune the seconds divider for the 32kHz clock in
fractional pulses so that the local clock second is phase locked to MSF
and it predicts how long to allow it to free run before forcing
synchronisation again. Most measure temperature, pressure and predict
the phase of the moon these days for good measure.

--
Regards,
Martin Brown

 

[AK]

On Thursday, May 2, 2019 at 2:54:59 AM UTC-5, Martin Brown wrote:

On 02/05/2019 01:15, gnuarm.deletethisbit@gmail.com wrote:
On Tuesday, April 30, 2019 at 5:51:05 AM UTC-4, Martin Brown wrote:
On 30/04/2019 00:10, AK wrote:
On Monday, April 29, 2019 at 4:17:30 PM UTC-5, Winfield Hill
wrote:
AK wrote...


I fully charged battery up. In a day, it dropped from 12.6 -
12.4 volts. I am happy with that. If it lasts a year, I will
be happy.

If it drops 0.2V/day, it'll drop 6V in 30 days, and it won't
last a year. How about you connect up your multimeter and find
out exactly how much current your clock takes? If it's too low
to see easily, set the meter to 200mV and measure across a
resistor.

9.6 milliamps

Is that how much current your clock draws or how much the
contraption you are powering your clock from is drawing? The
typical current consumption for an LCD atomic clock is somewhere
around 100uA or less.

They should last about two years on a fresh pair of AA batteries!

Funny, every one I've had used a single AA battery. Can't say what
the current is but I only expect them to run a year. Never actually
checked.

It is obviously possible to run them on a single cell just like LCD
watches do but many of them do use a pair of AA batteries. The important
point here is that no MSF clock of modern design should be drawing 10mA.

LCDs can be a bit dim on a single cell voltage unless you draw a bit
more current to run them from a voltage doubler.

The first one I ever built in the 1970's using an NE567 tone decoder did
draw ~10mA but using discrete components and it had no display at all.

These days almost all of them are a standard receiver module, decode
display module and an LCD display. The only clever bit is how they
discipline the local crystal oscillator and so how often they have to
turn on the receiver. Cheap and cheerful ones run it continuously. eg.

https://www.mas-oy.com/wp-content/uploads/2016/05/DAEV6181B1COB.pdf

Takes about 50uA and the display module is about the same.

The really smart ones tune the seconds divider for the 32kHz clock in
fractional pulses so that the local clock second is phase locked to MSF
and it predicts how long to allow it to free run before forcing
synchronisation again. Most measure temperature, pressure and predict
the phase of the moon these days for good measure.

--
Regards,
Martin Brown

There was no receiver module like what your link shows.

I now wonder if I got a "fake" atomic clock.



Andy

 

[AK]

On Thursday, May 2, 2019 at 2:54:59 AM UTC-5, Martin Brown wrote:

On 02/05/2019 01:15, gnuarm.deletethisbit@gmail.com wrote:
On Tuesday, April 30, 2019 at 5:51:05 AM UTC-4, Martin Brown wrote:
On 30/04/2019 00:10, AK wrote:
On Monday, April 29, 2019 at 4:17:30 PM UTC-5, Winfield Hill
wrote:
AK wrote...


I fully charged battery up. In a day, it dropped from 12.6 -
12.4 volts. I am happy with that. If it lasts a year, I will
be happy.

If it drops 0.2V/day, it'll drop 6V in 30 days, and it won't
last a year. How about you connect up your multimeter and find
out exactly how much current your clock takes? If it's too low
to see easily, set the meter to 200mV and measure across a
resistor.

9.6 milliamps

Is that how much current your clock draws or how much the
contraption you are powering your clock from is drawing? The
typical current consumption for an LCD atomic clock is somewhere
around 100uA or less.

They should last about two years on a fresh pair of AA batteries!

Funny, every one I've had used a single AA battery. Can't say what
the current is but I only expect them to run a year. Never actually
checked.

It is obviously possible to run them on a single cell just like LCD
watches do but many of them do use a pair of AA batteries. The important
point here is that no MSF clock of modern design should be drawing 10mA.

LCDs can be a bit dim on a single cell voltage unless you draw a bit
more current to run them from a voltage doubler.

The first one I ever built in the 1970's using an NE567 tone decoder did
draw ~10mA but using discrete components and it had no display at all.

These days almost all of them are a standard receiver module, decode
display module and an LCD display. The only clever bit is how they
discipline the local crystal oscillator and so how often they have to
turn on the receiver. Cheap and cheerful ones run it continuously. eg.

https://www.mas-oy.com/wp-content/uploads/2016/05/DAEV6181B1COB.pdf

Takes about 50uA and the display module is about the same.

The really smart ones tune the seconds divider for the 32kHz clock in
fractional pulses so that the local clock second is phase locked to MSF
and it predicts how long to allow it to free run before forcing
synchronisation again. Most measure temperature, pressure and predict
the phase of the moon these days for good measure.

--
Regards,
Martin Brown

I decided to look at the LCD in the clock.

When I took the board apart from the case, there was no longer anything displaying. After reattaching it, the display came back on with the current time. Apparently, the board needs physical contact with the display?

Andy
Andy

 

[AK]

On Thursday, May 2, 2019 at 2:32:09 PM UTC-5, AK wrote:

On Thursday, May 2, 2019 at 2:54:59 AM UTC-5, Martin Brown wrote:
On 02/05/2019 01:15, gnuarm.deletethisbit@gmail.com wrote:
On Tuesday, April 30, 2019 at 5:51:05 AM UTC-4, Martin Brown wrote:
On 30/04/2019 00:10, AK wrote:
On Monday, April 29, 2019 at 4:17:30 PM UTC-5, Winfield Hill
wrote:
AK wrote...


I fully charged battery up. In a day, it dropped from 12.6 -
12.4 volts. I am happy with that. If it lasts a year, I will
be happy.

If it drops 0.2V/day, it'll drop 6V in 30 days, and it won't
last a year. How about you connect up your multimeter and find
out exactly how much current your clock takes? If it's too low
to see easily, set the meter to 200mV and measure across a
resistor.

9.6 milliamps

Is that how much current your clock draws or how much the
contraption you are powering your clock from is drawing? The
typical current consumption for an LCD atomic clock is somewhere
around 100uA or less.

They should last about two years on a fresh pair of AA batteries!

Funny, every one I've had used a single AA battery. Can't say what
the current is but I only expect them to run a year. Never actually
checked.

It is obviously possible to run them on a single cell just like LCD
watches do but many of them do use a pair of AA batteries. The important
point here is that no MSF clock of modern design should be drawing 10mA..

LCDs can be a bit dim on a single cell voltage unless you draw a bit
more current to run them from a voltage doubler.

The first one I ever built in the 1970's using an NE567 tone decoder did
draw ~10mA but using discrete components and it had no display at all.

These days almost all of them are a standard receiver module, decode
display module and an LCD display. The only clever bit is how they
discipline the local crystal oscillator and so how often they have to
turn on the receiver. Cheap and cheerful ones run it continuously. eg.

https://www.mas-oy.com/wp-content/uploads/2016/05/DAEV6181B1COB.pdf

Takes about 50uA and the display module is about the same.

The really smart ones tune the seconds divider for the 32kHz clock in
fractional pulses so that the local clock second is phase locked to MSF
and it predicts how long to allow it to free run before forcing
synchronisation again. Most measure temperature, pressure and predict
the phase of the moon these days for good measure.

--
Regards,
Martin Brown


There was no receiver module like what your link shows.

I now wonder if I got a "fake" atomic clock.



Andy

In the United States, the signals received by radio controlled clocks originate from NIST Radio Station WWVB, which is located near Fort Collins, Colorado. WWVB broadcasts on a frequency of 60 kHz. Your radio controlled clock actually has a miniature radio receiver inside, which is permanently tuned to receive the 60 kHz signal.

 

[Martin Brown]

On 02/05/2019 20:32, AK wrote:

On Thursday, May 2, 2019 at 2:54:59 AM UTC-5, Martin Brown wrote:

These days almost all of them are a standard receiver module, decode
display module and an LCD display. The only clever bit is how they
discipline the local crystal oscillator and so how often they have to
turn on the receiver. Cheap and cheerful ones run it continuously. eg.

https://www.mas-oy.com/wp-content/uploads/2016/05/DAEV6181B1COB.pdf

Takes about 50uA and the display module is about the same.

The really smart ones tune the seconds divider for the 32kHz clock in
fractional pulses so that the local clock second is phase locked to MSF
and it predicts how long to allow it to free run before forcing
synchronisation again. Most measure temperature, pressure and predict
the phase of the moon these days for good measure.

There was no receiver module like what your link shows.

Mass produced they may just go with the bare chip but they will
certainly have the crystals (or ceramic) filters if it is genuine.

I now wonder if I got a "fake" atomic clock.

Was there a coil on a ferrite rod in it? If there was then following the
leads from that should find a blob like preamp IC and 60kHz and 77KhZ
xtals. If not then it seems your atomic clock isn't.

There will also probably be a 32768Hz watch xtal as well.

--
Regards,
Martin Brown