I have various USB chargers, cords, and portable devices around the
house. One of my devices, a Kindle Fire from around 2013, which works
fine, seems to have a nonlinear charging rate. Maybe that's OK. I don't
know. For example, it seems to take much longer to go from 15% to 16%
than from 95%-100%. In any case, I'd be curious to know how much the
charging current is fluctuating and if there is any variation in
performance between the wall chargers I have in my drawer. There's a
very large selection of USB power analyzers available but I mostly want >something that will test "C" ports as well as the older ones. Any >recommendations? It seems that every review I read contains more than a
few complaints about reliability and sturdiness.
Thanks for your reply.
On Sat, 5 Feb 2022 10:54:40 -0800, David FarberHi RL,
<farberbear.unspam@aol.com> wrote:
I have various USB chargers, cords, and portable devices around the
house. One of my devices, a Kindle Fire from around 2013, which works
fine, seems to have a nonlinear charging rate. Maybe that's OK. I don't
know. For example, it seems to take much longer to go from 15% to 16%
than from 95%-100%. In any case, I'd be curious to know how much the
charging current is fluctuating and if there is any variation in
performance between the wall chargers I have in my drawer. There's a
very large selection of USB power analyzers available but I mostly want
something that will test "C" ports as well as the older ones. Any
recommendations? It seems that every review I read contains more than a
few complaints about reliability and sturdiness.
Thanks for your reply.
More likely to be a non-linearity in the gauge monitoring
method. A 15% gauge is a crude guess - a 95% gauge will
depend on settings and tolerances. Both reported values
will likely shift dramatically when transferring from charge
to discharge mode or vice versa.
A linear charger, thermally limited, will be more restricted
in delivering power when the battery terminal voltage is lower
(bigger drop across the regulator). Linears will only be found
in the oldest or cheapest devices, at USB power and voltage
levels.
The deviation you've noted is probably not worth the time,
trouble or expense to pursue, unless you're in the design/ build/test/repair/volume-trade businesses.
RL
Consider a battery very similar to a clock spring. And the charger similar to the key winding that spring. The key turns at a constant rate, so the first 30 (of 100) turns seems to do almost nothing. Whereas the last turn requires the most effort andgives the largest measurable results. The gauge that you are reading measures the tension on the spring, not how fully it is wound, but for practical purposes, the same thing at the end of the process. Charging a battery is by no means similar to filling
Peter Wieck
Melrose Park, PA
Consider a battery very similar to a clock spring. And the charger similar to the key winding that spring. The key turns at a constant rate, so the first 30 (of 100) turns seems to do almost nothing. Whereas the last turn requires the most effort andgives the largest measurable results.
I have various USB chargers, cords, and portable devices around the
house. One of my devices, a Kindle Fire from around 2013, which works
fine, seems to have a nonlinear charging rate. Maybe that's OK. I don't
know. For example, it seems to take much longer to go from 15% to 16%
than from 95%-100%. In any case, I'd be curious to know how much the
charging current is fluctuating and if there is any variation in
performance between the wall chargers I have in my drawer. There's a
very large selection of USB power analyzers available but I mostly want >something that will test "C" ports as well as the older ones. Any >recommendations? It seems that every review I read contains more than a
few complaints about reliability and sturdiness.
Thanks for your reply.
I have various USB chargers, cords, and portable devices around the
house. One of my devices, a Kindle Fire from around 2013, which works
fine, seems to have a nonlinear charging rate. Maybe that's OK. I don't
know. For example, it seems to take much longer to go from 15% to 16%
than from 95%-100%. In any case, I'd be curious to know how much the
charging current is fluctuating and if there is any variation in
performance between the wall chargers I have in my drawer. There's a
very large selection of USB power analyzers available but I mostly want something that will test "C" ports as well as the older ones. Any recommendations? It seems that every review I read contains more than a
few complaints about reliability and sturdiness.
Thanks for your reply.
Clock springs are usually retained inside a barrel (except in the
cheapest clocks), so that each turn of the winding key unfurls another rotation of the spring from being tight against the inside of the rest
of the spring. This results in *very little* progression of spring force from run-down to fully wound. This is essential to proper time-keeping, depending on the Q of the escapement mechanism (a Q of say 100 means
that the spring force can affect 1% of the clock's rate, clearly unacceptable).
On 2/5/2022 1:01 PM, legg wrote:
On Sat, 5 Feb 2022 10:54:40 -0800, David FarberHi RL,
<farberbear.unspam@aol.com> wrote:
I have various USB chargers, cords, and portable devices around the
house. One of my devices, a Kindle Fire from around 2013, which works
fine, seems to have a nonlinear charging rate. Maybe that's OK. I don't
know. For example, it seems to take much longer to go from 15% to 16%
than from 95%-100%. In any case, I'd be curious to know how much the
charging current is fluctuating and if there is any variation in
performance between the wall chargers I have in my drawer. There's a
very large selection of USB power analyzers available but I mostly want
something that will test "C" ports as well as the older ones. Any
recommendations? It seems that every review I read contains more than a
few complaints about reliability and sturdiness.
Thanks for your reply.
More likely to be a non-linearity in the gauge monitoring
method. A 15% gauge is a crude guess - a 95% gauge will
depend on settings and tolerances. Both reported values
will likely shift dramatically when transferring from charge
to discharge mode or vice versa.
A linear charger, thermally limited, will be more restricted
in delivering power when the battery terminal voltage is lower
(bigger drop across the regulator). Linears will only be found
in the oldest or cheapest devices, at USB power and voltage
levels.
The deviation you've noted is probably not worth the time,
trouble or expense to pursue, unless you're in the design/
build/test/repair/volume-trade businesses.
RL
Thanks for all those operational details but these USB power meters are
not that expensive:
https://www.amazon.com/s?k=usb+power+analyzer&sprefix=usb+power+anal%2Caps%2C502
Most of them are in the $10-$40 range. My Kindle can take more than 8
hours to charge so I'd like to do some investigating.
Thanks for your reply.
much cheaper than before, as to get that level of accuracy, they often required a fusee drive. And for exactly the reason given. Any escapement with backlash as you suggest, allows the drive force (spring) to overcome theClock springs are usually retained inside a barrel (except in the
cheapest clocks), so that each turn of the winding key unfurls another rotation of the spring from being tight against the inside of the rest
of the spring. This results in *very little* progression of spring force from run-down to fully wound. This is essential to proper time-keeping, depending on the Q of the escapement mechanism (a Q of say 100 means
that the spring force can affect 1% of the clock's rate, clearly unacceptable).
Here in the US, spring-driven pendulum clocks did not, and do not, for the most part, use barrels. They did, however, use the deadbeat escapement (Seth Thomas patent in the US) that does tolerate a wide range of spring force. Making accurate clocks
Peter Wieck
Melrose Park, PA
In article <stmh5d$shc$1@dont-email.me>, farberbear.unspam@aol.com
says...
I have various USB chargers, cords, and portable devices around the
house. One of my devices, a Kindle Fire from around 2013, which works
fine, seems to have a nonlinear charging rate. Maybe that's OK. I don't
know. For example, it seems to take much longer to go from 15% to 16%
than from 95%-100%. In any case, I'd be curious to know how much the
charging current is fluctuating and if there is any variation in
performance between the wall chargers I have in my drawer. There's a
very large selection of USB power analyzers available but I mostly want
something that will test "C" ports as well as the older ones. Any
recommendations? It seems that every review I read contains more than a
few complaints about reliability and sturdiness.
Thanks for your reply.
I think this was the one I bought. I am very happy with it but don't
have much need for the power sink add-on or the built-in mAh accumulator
etc. I think it also monitors the charge control negotiation and
displays the result. There's a user-manual PDF link.
On Sat, 5 Feb 2022 10:54:40 -0800, David Farber
<farberbear.unspam@aol.com> wrote as underneath :
I have various USB chargers, cords, and portable devices around the
house. One of my devices, a Kindle Fire from around 2013, which works
fine, seems to have a nonlinear charging rate. Maybe that's OK. I don't >>know. For example, it seems to take much longer to go from 15% to 16%
than from 95%-100%. In any case, I'd be curious to know how much the >>charging current is fluctuating and if there is any variation in >>performance between the wall chargers I have in my drawer. There's a
very large selection of USB power analyzers available but I mostly want >>something that will test "C" ports as well as the older ones. Any >>recommendations? It seems that every review I read contains more than a
few complaints about reliability and sturdiness.
Thanks for your reply.
I have about 4 different makes/types over the years all Chinese, all
work on the A USB plug/socket Id have to find adaptors for use with
USBC. Just get the cheapest from eBay but make sure is counts mAh
cumulative with a reset as well as V and A, some dont. Some will read A
to .000 most only do 2 places. C+
On 2/6/2022 1:40 AM, Mike Coon wrote:
In article <stmh5d$shc$1@dont-email.me>, farberbear.unspam@aol.com
says...
I have various USB chargers, cords, and portable devices around the
house. One of my devices, a Kindle Fire from around 2013, which works
fine, seems to have a nonlinear charging rate. Maybe that's OK. I don't
know. For example, it seems to take much longer to go from 15% to 16%
than from 95%-100%. In any case, I'd be curious to know how much the
charging current is fluctuating and if there is any variation in
performance between the wall chargers I have in my drawer. There's a
very large selection of USB power analyzers available but I mostly want
something that will test "C" ports as well as the older ones. Any
recommendations? It seems that every review I read contains more than a
few complaints about reliability and sturdiness.
Thanks for your reply.
I think this was the one I bought. I am very happy with it but don't
have much need for the power sink add-on or the built-in mAh accumulator etc. I think it also monitors the charge control negotiation and
displays the result. There's a user-manual PDF link.
Hi Mike,
Did you inadvertently leave out the description of, "... the one I bought"?
Thanks for your reply.
much cheaper than before, as to get that level of accuracy, they often required a fusee drive. And for exactly the reason given. Any escapement with backlash as you suggest, allows the drive force (spring) to overcome the pendulum swing, introducing allClock springs are usually retained inside a barrel (except in the
cheapest clocks), so that each turn of the winding key unfurls another
rotation of the spring from being tight against the inside of the rest
of the spring. This results in *very little* progression of spring force
from run-down to fully wound. This is essential to proper time-keeping,
depending on the Q of the escapement mechanism (a Q of say 100 means
that the spring force can affect 1% of the clock's rate, clearly
unacceptable).
Here in the US, spring-driven pendulum clocks did not, and do not, for the most part, use barrels. They did, however, use the deadbeat escapement (Seth Thomas patent in the US) that does tolerate a wide range of spring force. Making accurate clocks
I have various USB chargers, cords, and portable devices around the
house. One of my devices, a Kindle Fire from around 2013,
it seems to take much longer to go from 15% to 16%
than from 95%-100%.
In any case, I'd be curious to know how much the
charging current is fluctuating and if there is any variation in
performance between the wall chargers I have in my drawer.
There's a
very large selection of USB power analyzers available but I mostly want >something that will test "C" ports as well as the older ones. Any >recommendations? It seems that every review I read contains more than a
few complaints about reliability and sturdiness.
Thanks for your reply.
On Sat, 5 Feb 2022 10:54:40 -0800, David Farber
<farberbear.unspam@aol.com> wrote:
I have various USB chargers, cords, and portable devices around the
house. One of my devices, a Kindle Fire from around 2013,
That's 9 years old. You could be dealing with an almost dead battery.
Complaint: EVERY time you post a question, you either leave out or
truncate the details on what you're working with. Some Kindle Fire
models have "issues" and it's helpful to look for these "issues" or
recalls before assaulting the alleged symptoms. In this case, None/HD/HDX/Kids, screen size, and what year Kindle Fire. Extra
credit for some details on the charger. <https://www.mobilefun.co.uk/blog/2014/07/how-to-identify-your-kindle-model/>
it seems to take much longer to go from 15% to 16%
than from 95%-100%.
Hmmm... That's about what I would guess happens when you plug in an underpowered charger. As I vaguely recall, some of the Kindle tablets required a 5V 1.5A or 2.0A charger. Commodity chargers only deliver
0.5A. If the USB controller chip in the charger is over-heating, I
would expect something similar to what you're experiencing.
Perhaps providing how long it takes (in minutes) might also be
helpful? How long did it take to charge when it was new?
In any case, I'd be curious to know how much the
charging current is fluctuating and if there is any variation in
performance between the wall chargers I have in my drawer.
You won't see much of that with an inline USB power meter unless you
want to record voltage and current every few minutes and draw a graph. Something like this:
"USB Current Sensor"
<https://www.sparkfun.com/products/18016>
Software:
<https://github.com/sparkfunX/USB_Current_Sensor>
Setup your computah as a data logger and measure the voltage output
produced by the current sensor (1amp = 1volt). Graph the results and
you can see what it's doing. My guess(tm) is that the graph is going
to be far more erratic than you've already observed. If you don't
want a pretty graph, just use the current senor and put voltmeters
across the 5V line for the voltage, and across the output for current.
Also, put an oscilloscope across USB 5V line. You might see
oscillation and/or noise spikes.
There's a
very large selection of USB power analyzers available but I mostly want
something that will test "C" ports as well as the older ones. Any
recommendations? It seems that every review I read contains more than a
few complaints about reliability and sturdiness.
I only have a pile of USB 2.0 type volt/amp USB meters. For fun, I
put them all in series and compared readings. Not too horrible +/-5%
on both voltage and current. However, you need something that will do
USB 3.0:
<https://www.ebay.com/sch/i.html?_nkw=usb+3.0+tester>
Thanks for your reply.
Gone to split some more firewood.
I found a few
references that indicate that the Kindle Fire HD 7 3rd generation
supports PD (power delivery) for fast charging.
The Kindle model is: P48WVB4 otherwise known as a Fire HD (3rd
generation) with a 7" screen.
On the back, near the model number it says
"Input: 5.0 VDC MAX 1.8A"
I received the device 2nd hand when the owner
upgraded to a new one. I don't have the original charger.
I have three
chargers which came from various devices and sources. Two of them are
5.0 VDC 1A and the third one is, 5.0 VDC 0.85A.
I have three USB cords.
One is quite old and I suspect this is part of the problem.
I viewed the link to the current sensor tool you mentioned >(https://github.com/sparkfunX/USB_Current_Sensor). Though it does not
have a display, it does have output terminals which the others do not.
Again, I think the problem my Kindle has is a loose connection or a bad
wire that can be easily detected by just monitoring the current while
tapping on the connectors and flexing the wires.
The battery when fully
charged, will last around a week before needing to be recharged. I use
it from 1-3 hours a day and leave the wireless disabled and brightness
set to one step above minimum as I read in the evening with the text set
to a white font and the background set to dark.
On Sun, 06 Feb 2022 07:19:16 +0000, Charlie+ <charlie@xxx.net> wrote:
On Sat, 5 Feb 2022 10:54:40 -0800, David Farber
<farberbear.unspam@aol.com> wrote as underneath :
I have various USB chargers, cords, and portable devices around the >>>house. One of my devices, a Kindle Fire from around 2013, which works >>>fine, seems to have a nonlinear charging rate. Maybe that's OK. I don't >>>know. For example, it seems to take much longer to go from 15% to 16% >>>than from 95%-100%. In any case, I'd be curious to know how much the >>>charging current is fluctuating and if there is any variation in >>>performance between the wall chargers I have in my drawer. There's a
very large selection of USB power analyzers available but I mostly want >>>something that will test "C" ports as well as the older ones. Any >>>recommendations? It seems that every review I read contains more than a >>>few complaints about reliability and sturdiness.
Thanks for your reply.
I have about 4 different makes/types over the years all Chinese, all
work on the A USB plug/socket Id have to find adaptors for use with
USBC. Just get the cheapest from eBay but make sure is counts mAh >>cumulative with a reset as well as V and A, some dont. Some will read A
to .000 most only do 2 places. C+
These will not tell you actual battery status as they have no access
to the battery terminals - only converter socket input and output.
Currents will differ on both sides of the converters, in both
directions and the external dongle will ignore the influence of
both battery charging efficiency and converter losses in the
transactions.
. . . but then so do most built-in gauges, even for varying internal >consumption. The best you'll ever get is a ball park estimate that
your own experience has to qualify.
On 2/5/2022 1:01 PM, legg wrote:
On Sat, 5 Feb 2022 10:54:40 -0800, David Farber
<farberbe...@aol.com> wrote:
I have various USB chargers, cords, and portable devices around the
house. One of my devices, a Kindle Fire from around 2013, which works
fine, seems to have a nonlinear charging rate. Maybe that's OK. I don't
know. For example, it seems to take much longer to go from 15% to 16%
than from 95%-100%. In any case, I'd be curious to know how much the
charging current is fluctuating and if there is any variation in
performance between the wall chargers I have in my drawer.
The deviation you've noted is probably not worth the time,
trouble or expense to pursue, unless you're in the design/ build/test/repair/volume-trade businesses.
On Sun, 06 Feb 2022 18:54:30 -0800, Jeff Liebermann <jeffl@cruzio.com>
wrote:
I found a few
references that indicate that the Kindle Fire HD 7 3rd generation
supports PD (power delivery) for fast charging.
That's wrong. I did some more digging and could not find any
references to the Kindle Fire HD 7 2013 3rd generation supporting PD
(power delivery). The closest approximation to a spec sheet doesn't
mention PD (or any other fast charging specs): <https://en.wikipedia.org/wiki/Fire_HD>
Therefore, any 5V charger that will provide 2amps (10 watts) and a USB
2.0 Micro-B connector, should work.
You have to install National Instruments VISA package, Microsoft
Studio, Labview elements yada yada and 2Meg worth of licensing
agreements to use a $22 USB power test dongle?
On 2/6/2022 7:07 PM, Jeff Liebermann wrote:<snip>
On Sun, 06 Feb 2022 18:54:30 -0800, Jeff Liebermann <jeffl@cruzio.com>I bought the MarkerHawk USB tester, Model3. >https://www.amazon.com/dp/B07DCSNHNB
wrote:
I found a few
references that indicate that the Kindle Fire HD 7 3rd generation
supports PD (power delivery) for fast charging.
That's wrong. I did some more digging and could not find any
references to the Kindle Fire HD 7 2013 3rd generation supporting PD
(power delivery). The closest approximation to a spec sheet doesn't
mention PD (or any other fast charging specs):
<https://en.wikipedia.org/wiki/Fire_HD>
Therefore, any 5V charger that will provide 2amps (10 watts) and a USB
2.0 Micro-B connector, should work.
I've been using it for a while now and it's quite good though it's not
enclosed in a case and the buttons (which are bare microswitches) are
mounted sideways AND recessed so they're not that easy to press. Also,
you cannot view all the data on one screen. Most notably to view the
elapsed charging time you need several button presses to switch screens
and then several more button presses to return to the main screen. The >features are nice but I wish I had gotten the 3B model which includes >Bluetooth capabilities. This would have allowed me to use the included >software on my laptop. Anyway, I noticed the biggest effect on the
charging current was the type of cord I was using. I have a couple of
skinny micro USB cords and one thicker cord. The thicker cord will
register 3 times as much current as the thinner ones and that's why the >charging times were not consistent.
things were progressing so I stopped monitoring the charging current.
In summary, it's a nice tool to use but the owner's manual...
https://drive.google.com/file/d/1ZFC9TEPUBI5vD081lVSdVgsmeWRnaqi9/view?usp=sharing
...takes some time to absorb as it's apparently been translated from
another language. Maybe one of you could explain the importance (or >unimportance) in knowing the voltages for the DP+ and DP- (data lines
+/-)? Speaking of data lines, I noticed some of my cords will not
transfer data and can only be used for charging. The thicker cord I was
using does have the ability to transfer data so I'm wondering if there's
some kind of communication going on between the charger and the Kindle
that affects the charging rate.
Thanks for your reply.
In summary, it's a nice tool to use but the owner's manual...
https://drive.google.com/file/d/1ZFC9TEPUBI5vD081lVSdVgsmeWRnaqi9/view?usp=sharing
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