On Sunday, February 13, 2022 at 9:16:58 PM UTC, Custos Custodum wrote:
On Sun, 13 Feb 2022 12:52:31 -0800 (PST), jkn <jkn...@nicorp.f9.co.uk>
wrote:
On Sunday, February 13, 2022 at 8:33:42 PM UTC, Commander Kinsey wrote:
https://imgur.com/a/b8l5qKQ
Look at the circuit diagram. The positive of the battery is only connected through a capacitor. How can a capacitor possibly pass DC current to allow the battery to charge?
What else might that yellow thing be, other than a capacitor?
A thermistor or a VDR, to provide current limiting.
Regarding operation, power diodes tend to have a higher Vf than small
signal diodes or transistor junctions, so once the diode goes into
conduction it produces a large enough voltage to turn on the
transistor and the red LED, indicating that charging is taking place.
The green LED merely indicates that power is applied to the circuit.
My (probably futile) hope was that he might answer it himself,
or at least try to...
On Sunday, February 13, 2022 at 3:33:49 PM UTC-5, Commander Kinsey wrote:
https://imgur.com/a/b8l5qKQ
Look at the circuit diagram. The positive of the battery is only connected through a capacitor. How can a capacitor possibly pass DC current to allow the battery to charge?
Maybe it's an AC battery? They are very useful for grid storage applications as long as you can control the phase.
What makes you think that component is a capacitor? I'm assuming you drew the schematic.
Commander Kinsey wrote:
=====================
** It's "self resetting".
What makes you think that component is a capacitor? I'm assuming you drew the schematic.
I've learned from someone on Quora that it's actually a PTC Fuse - a resettable semiconductor fuse.
Goes high resistance when hot and drops backs when cool.
The second image in the link shows a brown disk, which I thought was a ceramic capacitor.
** Shame about the odd markings.
Looks like it's to stop a busted battery from being overcharged when a cell has died.
** Nope.
Would only act on a short or reverse connected battery.
On Sun, 13 Feb 2022 21:56:55 -0000, jkn <jkn_gg@nicorp.f9.co.uk> wrote:
On Sunday, February 13, 2022 at 9:16:58 PM UTC, Custos Custodum wrote:
On Sun, 13 Feb 2022 12:52:31 -0800 (PST), jkn <jkn...@nicorp.f9.co.uk>
wrote:
On Sunday, February 13, 2022 at 8:33:42 PM UTC, Commander Kinseywrote:
connected through a capacitor. How can a capacitor possibly pass DChttps://imgur.com/a/b8l5qKQ
Look at the circuit diagram. The positive of the battery is only
current to allow the battery to charge?
What else might that yellow thing be, other than a capacitor?
A thermistor or a VDR, to provide current limiting.
Regarding operation, power diodes tend to have a higher Vf than small
signal diodes or transistor junctions, so once the diode goes into
conduction it produces a large enough voltage to turn on the
transistor and the red LED, indicating that charging is taking place.
The green LED merely indicates that power is applied to the circuit.
My (probably futile) hope was that he might answer it himself,
or at least try to...
I didn't expect two completely different devices to look identical. So
how the fuck am I supposed to tell which one is?
On Sunday, February 13, 2022 at 5:34:04 PM UTC-5, Commander Kinsey wrote:
On Sun, 13 Feb 2022 20:55:51 -0000, Rick C <gnuarm.del...@gmail.com> wrote: >>
On Sunday, February 13, 2022 at 3:33:49 PM UTC-5, Commander Kinsey wrote: >> >> https://imgur.com/a/b8l5qKQI've learned from someone on Quora that it's actually a PTC Fuse - a resettable semiconductor fuse.
Look at the circuit diagram. The positive of the battery is only connected through a capacitor. How can a capacitor possibly pass DC current to allow the battery to charge?
Maybe it's an AC battery? They are very useful for grid storage applications as long as you can control the phase.
What makes you think that component is a capacitor? I'm assuming you drew the schematic.
The second image in the link shows a brown disk, which I thought was a ceramic capacitor. Looks like it's to stop a busted battery from being overcharged when a cell has died.
It won't do that. It is simply a fuse that prevents too high a current from flowing, such as if you connected the battery backwards.
I'm not sure what this circuit is supposed to do. It doesn't look right to me.
On Sun, 13 Feb 2022 21:56:55 -0000, jkn <jkn_gg@nicorp.f9.co.uk> wrote:
On Sunday, February 13, 2022 at 9:16:58 PM UTC, Custos Custodum wrote:
On Sun, 13 Feb 2022 12:52:31 -0800 (PST), jkn <jkn...@nicorp.f9.co.uk>
wrote:
On Sunday, February 13, 2022 at 8:33:42 PM UTC, Commander Kinsey wrote: >>> >> https://imgur.com/a/b8l5qKQ
Look at the circuit diagram. The positive of the battery is only connected through a capacitor. How can a capacitor possibly pass DC current to allow the battery to charge?
What else might that yellow thing be, other than a capacitor?
A thermistor or a VDR, to provide current limiting.
Regarding operation, power diodes tend to have a higher Vf than small
signal diodes or transistor junctions, so once the diode goes into
conduction it produces a large enough voltage to turn on the
transistor and the red LED, indicating that charging is taking place.
The green LED merely indicates that power is applied to the circuit.
My (probably futile) hope was that he might answer it himself,
or at least try to...
I didn't expect two completely different devices to look identical. So how the fuck am I supposed to tell which one is?
https://imgur.com/a/b8l5qKQ
Look at the circuit diagram. The positive of the battery is only connected through a capacitor. How can a capacitor possibly pass DC current to allow the battery to charge?
On Sunday, February 13, 2022 at 6:08:03 PM UTC-5, Commander Kinsey wrote:LiIon.
On Sun, 13 Feb 2022 23:02:03 -0000, Rick C <gnuarm.del...@gmail.com> wrote: >>
On Sunday, February 13, 2022 at 5:34:04 PM UTC-5, Commander Kinsey wrote: >> >> On Sun, 13 Feb 2022 20:55:51 -0000, Rick C <gnuarm.del...@gmail.com> wrote:Surely a higher current would flow if the battery became 9 cells instead of 10 because one failed and became zero volts? Ever tried charging a car battery with 14V when it only contains 5 working cells? The others boil.
On Sunday, February 13, 2022 at 3:33:49 PM UTC-5, Commander Kinsey wrote:I've learned from someone on Quora that it's actually a PTC Fuse - a resettable semiconductor fuse.
https://imgur.com/a/b8l5qKQ
Look at the circuit diagram. The positive of the battery is only connected through a capacitor. How can a capacitor possibly pass DC current to allow the battery to charge?
Maybe it's an AC battery? They are very useful for grid storage applications as long as you can control the phase.
What makes you think that component is a capacitor? I'm assuming you drew the schematic.
The second image in the link shows a brown disk, which I thought was a ceramic capacitor. Looks like it's to stop a busted battery from being overcharged when a cell has died.
It won't do that. It is simply a fuse that prevents too high a current from flowing, such as if you connected the battery backwards.
I'm not sure what this circuit is supposed to do. It doesn't look right to me.It's the (5 hour) charger for a very cheap cordless drill. The input is a 14.4V wall wart. The output is to a pack of NiCad cells. It's worked fine for years, until I can no longer find replacement NiCad cells, so I'm converting the battery packs to
My point is this circuit isn't setting the voltage or limiting current other than through the fuse.
It appears to be a couple of LEDs that indicate the battery is charging and/or has power.
The diode will prevent the transistor from ever turning on more than a tiny amount, but with the gain of the transistor the red LED is turned on with a small current in the transistor BE path. It could be more clear if you redraw it with the base onthe right, the resistor to the right of that and the diode across the two. The two resistors and the green LED probably should be on the left, where power comes in. That's all they do is indicate the presence of power.
In any event, it is the wall wart that would seem to be doing all the work of charging the battery, setting the max current and the max voltage just by having a significant series resistance most likely.
That's why the fuse is not needed for a shorted cell. Being at 11V instead of 14V isn't enough to make the current jump so much. A short or reversed battery is a different matter.
On Sun, 13 Feb 2022 22:47:41 -0000, "Commander Kinsey"
<CK1@nospam.com> wrote:
On Sun, 13 Feb 2022 21:56:55 -0000, jkn <jkn_gg@nicorp.f9.co.uk> wrote:
On Sunday, February 13, 2022 at 9:16:58 PM UTC, Custos Custodum wrote:
On Sun, 13 Feb 2022 12:52:31 -0800 (PST), jkn <jkn...@nicorp.f9.co.uk> >>>> wrote:
On Sunday, February 13, 2022 at 8:33:42 PM UTC, Commander Kinsey wrote: >>>> >> https://imgur.com/a/b8l5qKQ
Look at the circuit diagram. The positive of the battery is only connected through a capacitor. How can a capacitor possibly pass DC current to allow the battery to charge?
What else might that yellow thing be, other than a capacitor?
A thermistor or a VDR, to provide current limiting.
Regarding operation, power diodes tend to have a higher Vf than small
signal diodes or transistor junctions, so once the diode goes into
conduction it produces a large enough voltage to turn on the
transistor and the red LED, indicating that charging is taking place.
The green LED merely indicates that power is applied to the circuit.
My (probably futile) hope was that he might answer it himself,
or at least try to...
I didn't expect two completely different devices to look identical. So how the fuck am I supposed to tell which one is?
Try an ohmmeter.
Unless NiCads are vastly different to car batteries, one shorted cell
makes a hell of a lot more current flow.
On Sunday, February 13, 2022 at 7:39:08 PM UTC-5, Commander Kinsey wrote:
On Sun, 13 Feb 2022 23:59:33 -0000, <jla...@highlandsniptechnology.com> wrote:
On Sun, 13 Feb 2022 22:47:41 -0000, "Commander Kinsey"Not so easy when in the middle of a big circuit.
<C...@nospam.com> wrote:
On Sun, 13 Feb 2022 21:56:55 -0000, jkn <jkn...@nicorp.f9.co.uk> wrote: >> >>
On Sunday, February 13, 2022 at 9:16:58 PM UTC, Custos Custodum wrote: >> >>>> On Sun, 13 Feb 2022 12:52:31 -0800 (PST), jkn <jkn...@nicorp.f9.co.uk> >> >>>> wrote:
On Sunday, February 13, 2022 at 8:33:42 PM UTC, Commander Kinsey wrote:
https://imgur.com/a/b8l5qKQ
Look at the circuit diagram. The positive of the battery is only connected through a capacitor. How can a capacitor possibly pass DC current to allow the battery to charge?
What else might that yellow thing be, other than a capacitor?
A thermistor or a VDR, to provide current limiting.
Regarding operation, power diodes tend to have a higher Vf than small >> >>>> signal diodes or transistor junctions, so once the diode goes into
conduction it produces a large enough voltage to turn on the
transistor and the red LED, indicating that charging is taking place. >> >>>> The green LED merely indicates that power is applied to the circuit.
My (probably futile) hope was that he might answer it himself,
or at least try to...
I didn't expect two completely different devices to look identical. So how the fuck am I supposed to tell which one is?
Try an ohmmeter.
One end of it is connected only to the battery which I believe you can remove.
williamwright <wrightsaerials@f2s.com> wrote
Commander Kinsey wrote
Unless NiCads are vastly different to car batteries, oneshorted cell
makes a hell of a lot more current flow.
They are vastly different.
Do they not both have a very low internal resistance? Therefore
connecting a 10V battery to a 12V charger makes too much current flow?
The second image in the link shows a brown disk, which I thought was a ceramic capacitor.
** Shame about the odd markings.
Those aren't shown in the pictures.
On 14/02/2022 00:47, Commander Kinsey wrote:
Unless NiCads are vastly different to car batteries, one shorted cell
makes a hell of a lot more current flow.
They are vastly different.
On Sunday, February 13, 2022 at 7:47:42 PM UTC-5, Commander Kinsey wrote:to LiIon.
On Mon, 14 Feb 2022 00:10:47 -0000, Rick C <gnuarm.del...@gmail.com> wrote: >>
On Sunday, February 13, 2022 at 6:08:03 PM UTC-5, Commander Kinsey wrote: >> >> On Sun, 13 Feb 2022 23:02:03 -0000, Rick C <gnuarm.del...@gmail.com> wrote:
On Sunday, February 13, 2022 at 5:34:04 PM UTC-5, Commander Kinsey wrote:Surely a higher current would flow if the battery became 9 cells instead of 10 because one failed and became zero volts? Ever tried charging a car battery with 14V when it only contains 5 working cells? The others boil.
On Sun, 13 Feb 2022 20:55:51 -0000, Rick C <gnuarm.del...@gmail.com> wrote:
On Sunday, February 13, 2022 at 3:33:49 PM UTC-5, Commander Kinsey wrote:I've learned from someone on Quora that it's actually a PTC Fuse - a resettable semiconductor fuse.
https://imgur.com/a/b8l5qKQ
Look at the circuit diagram. The positive of the battery is only connected through a capacitor. How can a capacitor possibly pass DC current to allow the battery to charge?
Maybe it's an AC battery? They are very useful for grid storage applications as long as you can control the phase.
What makes you think that component is a capacitor? I'm assuming you drew the schematic.
The second image in the link shows a brown disk, which I thought was a ceramic capacitor. Looks like it's to stop a busted battery from being overcharged when a cell has died.
It won't do that. It is simply a fuse that prevents too high a current from flowing, such as if you connected the battery backwards.
I'm not sure what this circuit is supposed to do. It doesn't look right to me.It's the (5 hour) charger for a very cheap cordless drill. The input is a 14.4V wall wart. The output is to a pack of NiCad cells. It's worked fine for years, until I can no longer find replacement NiCad cells, so I'm converting the battery packs
the right, the resistor to the right of that and the diode across the two. The two resistors and the green LED probably should be on the left, where power comes in. That's all they do is indicate the presence of power.It will be limited by the wall wart, which is a basic transformer and diodes. Since it's a 5 hour charge, it won't harm the battery to just keep going.
My point is this circuit isn't setting the voltage or limiting current other than through the fuse.
It appears to be a couple of LEDs that indicate the battery is charging and/or has power.Yes, the battery is basically just charged through the diode and fuse.
The diode will prevent the transistor from ever turning on more than a tiny amount, but with the gain of the transistor the red LED is turned on with a small current in the transistor BE path. It could be more clear if you redraw it with the base on
Yeah it was just a quick sketch to try to understand it.
In any event, it is the wall wart that would seem to be doing all the work of charging the battery, setting the max current and the max voltage just by having a significant series resistance most likely.Ah, you beat me to it.
That's why the fuse is not needed for a shorted cell. Being at 11V instead of 14V isn't enough to make the current jump so much. A short or reversed battery is a different matter.Unless NiCads are vastly different to car batteries, one shorted cell makes a hell of a lot more current flow.
THE WALL WART LIMITS THE CURRENT AND PREVENTS ANY ISSUES FROM A SINGLE SHORTED CELL.
Is that clear?
On Mon, 14 Feb 2022 01:24:36 -0000, Rick C
<gnuarm.deletethisbit@gmail.com> wrote:
On Sunday, February 13, 2022 at 7:47:42 PM UTC-5, Commander Kinsey wrote: >>> On Mon, 14 Feb 2022 00:10:47 -0000, Rick C <gnuarm.del...@gmail.com>
wrote:
On Sunday, February 13, 2022 at 6:08:03 PM UTC-5, Commander Kinseywrote:
<gnuarm.del...@gmail.com> wrote:On Sun, 13 Feb 2022 23:02:03 -0000, Rick C
Kinsey wrote:
On Sunday, February 13, 2022 at 5:34:04 PM UTC-5, Commander
<gnuarm.del...@gmail.com> wrote:On Sun, 13 Feb 2022 20:55:51 -0000, Rick C
Kinsey wrote:
On Sunday, February 13, 2022 at 3:33:49 PM UTC-5, Commander
only connected through a capacitor. How can a capacitor possibly passhttps://imgur.com/a/b8l5qKQ
Look at the circuit diagram. The positive of the battery is
DC current to allow the battery to charge?
storage applications as long as you can control the phase.
Maybe it's an AC battery? They are very useful for grid
assuming you drew the schematic.
What makes you think that component is a capacitor? I'm
Fuse - a resettable semiconductor fuse.I've learned from someone on Quora that it's actually a PTC
thought was a ceramic capacitor. Looks like it's to stop a busted
The second image in the link shows a brown disk, which I
battery from being overcharged when a cell has died.
current from flowing, such as if you connected the battery backwards.
It won't do that. It is simply a fuse that prevents too high a
instead of 10 because one failed and became zero volts? Ever triedSurely a higher current would flow if the battery became 9 cells
charging a car battery with 14V when it only contains 5 working
cells? The others boil.
look right to me.I'm not sure what this circuit is supposed to do. It doesn't
input is a 14.4V wall wart. The output is to a pack of NiCad cells.It's the (5 hour) charger for a very cheap cordless drill. The
It's worked fine for years, until I can no longer find replacement
NiCad cells, so I'm converting the battery packs to LiIon.
current other than through the fuse.
My point is this circuit isn't setting the voltage or limiting
It will be limited by the wall wart, which is a basic transformer and
diodes. Since it's a 5 hour charge, it won't harm the battery to just
keep going.
It appears to be a couple of LEDs that indicate the battery ischarging and/or has power.
Yes, the battery is basically just charged through the diode and fuse.
The diode will prevent the transistor from ever turning on morethan a tiny amount, but with the gain of the transistor the red LED
is turned on with a small current in the transistor BE path. It could
be more clear if you redraw it with the base on the right, the
resistor to the right of that and the diode across the two. The two
resistors and the green LED probably should be on the left, where
power comes in. That's all they do is indicate the presence of power.
Yeah it was just a quick sketch to try to understand it.
In any event, it is the wall wart that would seem to be doing allthe work of charging the battery, setting the max current and the max
voltage just by having a significant series resistance most likely.
Ah, you beat me to it.
That's why the fuse is not needed for a shorted cell. Being at 11Vinstead of 14V isn't enough to make the current jump so much. A short
or reversed battery is a different matter.
Unless NiCads are vastly different to car batteries, one shorted cell
makes a hell of a lot more current flow.
THE WALL WART LIMITS THE CURRENT AND PREVENTS ANY ISSUES FROM A SINGLE
SHORTED CELL.
Is that clear?
Yes, so why have the semiconductor fuse at all?
[other groups reinstated to stop you limiting the audience - others may
be reading this in another group]
Oh, you use google groups. My god man get a newsreader program.
THE WALL WART LIMITS THE CURRENT AND PREVENTS ANY ISSUES FROM A SINGLE SHORTED CELL.
Is that clear?
Yes, so why have the semiconductor fuse at all?
On Mon, 14 Feb 2022 00:42:20 -0000, Rick C <gnuarm.deletethisbit@gmail.com> wrote:
On Sunday, February 13, 2022 at 7:39:08 PM UTC-5, Commander Kinsey wrote: >>> On Sun, 13 Feb 2022 23:59:33 -0000, <jla...@highlandsniptechnology.com> wrote:
On Sun, 13 Feb 2022 22:47:41 -0000, "Commander Kinsey"Not so easy when in the middle of a big circuit.
<C...@nospam.com> wrote:
On Sun, 13 Feb 2022 21:56:55 -0000, jkn <jkn...@nicorp.f9.co.uk> wrote: >>> >>
On Sunday, February 13, 2022 at 9:16:58 PM UTC, Custos Custodum wrote: >>> >>>> On Sun, 13 Feb 2022 12:52:31 -0800 (PST), jkn <jkn...@nicorp.f9.co.uk> >>> >>>> wrote:
My (probably futile) hope was that he might answer it himself,On Sunday, February 13, 2022 at 8:33:42 PM UTC, Commander Kinsey wrote:
https://imgur.com/a/b8l5qKQ
Look at the circuit diagram. The positive of the battery is only connected through a capacitor. How can a capacitor possibly pass DC current to allow the battery to charge?
What else might that yellow thing be, other than a capacitor?
A thermistor or a VDR, to provide current limiting.
Regarding operation, power diodes tend to have a higher Vf than small >>> >>>> signal diodes or transistor junctions, so once the diode goes into
conduction it produces a large enough voltage to turn on the
transistor and the red LED, indicating that charging is taking place. >>> >>>> The green LED merely indicates that power is applied to the circuit. >>> >>>
or at least try to...
I didn't expect two completely different devices to look identical. So how the fuck am I supposed to tell which one is?
Try an ohmmeter.
One end of it is connected only to the battery which I believe you can remove.
In this case yes, but I was talking generically in other larger circuits where the capacitor/limiter could be in the middle of loads of other components.
Rick C <gnuarm.deletethisbit@gmail.com> wrote
On Sunday, February 13, 2022 at 7:47:42 PM UTC-5, Commander Kinsey
wrote:
On Mon, 14 Feb 2022 00:10:47 -0000, Rick C <gnuarm.del...@gmail.com>
wrote:
On Sunday, February 13, 2022 at 6:08:03 PM UTC-5, Commander Kinseywrote:
<gnuarm.del...@gmail.com> wrote:On Sun, 13 Feb 2022 23:02:03 -0000, Rick C
Kinsey wrote:
On Sunday, February 13, 2022 at 5:34:04 PM UTC-5, Commander
<gnuarm.del...@gmail.com> wrote:On Sun, 13 Feb 2022 20:55:51 -0000, Rick C
Kinsey wrote:
On Sunday, February 13, 2022 at 3:33:49 PM UTC-5, Commander
only connected through a capacitor. How can a capacitor possibly passhttps://imgur.com/a/b8l5qKQ
Look at the circuit diagram. The positive of the battery is
DC current to allow the battery to charge?
storage applications as long as you can control the phase.
Maybe it's an AC battery? They are very useful for grid
assuming you drew the schematic.
What makes you think that component is a capacitor? I'm
- a resettable semiconductor fuse.I've learned from someone on Quora that it's actually a PTC Fuse
was a ceramic capacitor. Looks like it's to stop a busted battery from
The second image in the link shows a brown disk, which I thought
being overcharged when a cell has died.
current from flowing, such as if you connected the battery backwards.
It won't do that. It is simply a fuse that prevents too high a
instead of 10 because one failed and became zero volts? Ever triedSurely a higher current would flow if the battery became 9 cells
charging a car battery with 14V when it only contains 5 working cells?
The others boil.
right to me.I'm not sure what this circuit is supposed to do. It doesn't look
input is a 14.4V wall wart. The output is to a pack of NiCad cells.It's the (5 hour) charger for a very cheap cordless drill. The
It's worked fine for years, until I can no longer find replacement
NiCad cells, so I'm converting the battery packs to LiIon.
current other than through the fuse.
My point is this circuit isn't setting the voltage or limiting
It will be limited by the wall wart, which is a basic transformer and
diodes. Since it's a 5 hour charge, it won't harm the battery to just
keep going.
It appears to be a couple of LEDs that indicate the battery ischarging and/or has power.
Yes, the battery is basically just charged through the diode and fuse.
The diode will prevent the transistor from ever turning on more thana tiny amount, but with the gain of the transistor the red LED is
turned on with a small current in the transistor BE path. It could be
more clear if you redraw it with the base on the right, the resistor
to the right of that and the diode across the two. The two resistors
and the green LED probably should be on the left, where power comes
in. That's all they do is indicate the presence of power.
Yeah it was just a quick sketch to try to understand it.
In any event, it is the wall wart that would seem to be doing allthe work of charging the battery, setting the max current and the max
voltage just by having a significant series resistance most likely.
Ah, you beat me to it.
That's why the fuse is not needed for a shorted cell. Being at 11Vinstead of 14V isn't enough to make the current jump so much. A short
or reversed battery is a different matter.
Unless NiCads are vastly different to car batteries, one shorted cell
makes a hell of a lot more current flow.
THE WALL WART LIMITS THE CURRENT AND PREVENTS ANY ISSUES FROM A SINGLE
SHORTED CELL.
Is that clear?
Yes, so why have the semiconductor fuse at all?
On 14/02/2022 03:04, Commander Kinsey wrote:
On Mon, 14 Feb 2022 01:24:36 -0000, Rick C
<gnuarm.deletethisbit@gmail.com> wrote:
On Sunday, February 13, 2022 at 7:47:42 PM UTC-5, Commander Kinsey wrote: >>>> On Mon, 14 Feb 2022 00:10:47 -0000, Rick C <gnuarm.del...@gmail.com>
wrote:
On Sunday, February 13, 2022 at 6:08:03 PM UTC-5, Commander Kinseywrote:
<gnuarm.del...@gmail.com> wrote:On Sun, 13 Feb 2022 23:02:03 -0000, Rick C
Kinsey wrote:
On Sunday, February 13, 2022 at 5:34:04 PM UTC-5, Commander
<gnuarm.del...@gmail.com> wrote:On Sun, 13 Feb 2022 20:55:51 -0000, Rick C
Kinsey wrote:
On Sunday, February 13, 2022 at 3:33:49 PM UTC-5, Commander
only connected through a capacitor. How can a capacitor possibly passhttps://imgur.com/a/b8l5qKQ
Look at the circuit diagram. The positive of the battery is
DC current to allow the battery to charge?
storage applications as long as you can control the phase.
Maybe it's an AC battery? They are very useful for grid
assuming you drew the schematic.
What makes you think that component is a capacitor? I'm
Fuse - a resettable semiconductor fuse.I've learned from someone on Quora that it's actually a PTC
thought was a ceramic capacitor. Looks like it's to stop a busted
The second image in the link shows a brown disk, which I
battery from being overcharged when a cell has died.
current from flowing, such as if you connected the battery backwards.
It won't do that. It is simply a fuse that prevents too high a
instead of 10 because one failed and became zero volts? Ever triedSurely a higher current would flow if the battery became 9 cells
charging a car battery with 14V when it only contains 5 working
cells? The others boil.
look right to me.I'm not sure what this circuit is supposed to do. It doesn't
input is a 14.4V wall wart. The output is to a pack of NiCad cells.It's the (5 hour) charger for a very cheap cordless drill. The
It's worked fine for years, until I can no longer find replacement
NiCad cells, so I'm converting the battery packs to LiIon.
current other than through the fuse.
My point is this circuit isn't setting the voltage or limiting
It will be limited by the wall wart, which is a basic transformer and
diodes. Since it's a 5 hour charge, it won't harm the battery to just
keep going.
It appears to be a couple of LEDs that indicate the battery ischarging and/or has power.
Yes, the battery is basically just charged through the diode and fuse. >>>> > The diode will prevent the transistor from ever turning on more
than a tiny amount, but with the gain of the transistor the red LED
is turned on with a small current in the transistor BE path. It could
be more clear if you redraw it with the base on the right, the
resistor to the right of that and the diode across the two. The two
resistors and the green LED probably should be on the left, where
power comes in. That's all they do is indicate the presence of power.
Yeah it was just a quick sketch to try to understand it.
In any event, it is the wall wart that would seem to be doing allthe work of charging the battery, setting the max current and the max
voltage just by having a significant series resistance most likely.
Ah, you beat me to it.
That's why the fuse is not needed for a shorted cell. Being at 11Vinstead of 14V isn't enough to make the current jump so much. A short
or reversed battery is a different matter.
Unless NiCads are vastly different to car batteries, one shorted cell
makes a hell of a lot more current flow.
THE WALL WART LIMITS THE CURRENT AND PREVENTS ANY ISSUES FROM A SINGLE
SHORTED CELL.
Is that clear?
Yes, so why have the semiconductor fuse at all?
[other groups reinstated to stop you limiting the audience - others may
be reading this in another group]
Oh, you use google groups. My god man get a newsreader program.
Why would anyone want to read your posts?
You ask stupid questions and don't understand the replies.
On Sunday, February 13, 2022 at 10:04:23 PM UTC-5, Commander Kinsey wrote:packs to LiIon.
On Mon, 14 Feb 2022 01:24:36 -0000, Rick C <gnuarm.del...@gmail.com> wrote: >>
On Sunday, February 13, 2022 at 7:47:42 PM UTC-5, Commander Kinsey wrote: >> >> On Mon, 14 Feb 2022 00:10:47 -0000, Rick C <gnuarm.del...@gmail.com> wrote:
On Sunday, February 13, 2022 at 6:08:03 PM UTC-5, Commander Kinsey wrote:
On Sun, 13 Feb 2022 23:02:03 -0000, Rick C <gnuarm.del...@gmail.com> wrote:
On Sunday, February 13, 2022 at 5:34:04 PM UTC-5, Commander Kinsey wrote:Surely a higher current would flow if the battery became 9 cells instead of 10 because one failed and became zero volts? Ever tried charging a car battery with 14V when it only contains 5 working cells? The others boil.
On Sun, 13 Feb 2022 20:55:51 -0000, Rick C <gnuarm.del...@gmail.com> wrote:
On Sunday, February 13, 2022 at 3:33:49 PM UTC-5, Commander Kinsey wrote:I've learned from someone on Quora that it's actually a PTC Fuse - a resettable semiconductor fuse.
https://imgur.com/a/b8l5qKQ
Look at the circuit diagram. The positive of the battery is only connected through a capacitor. How can a capacitor possibly pass DC current to allow the battery to charge?
Maybe it's an AC battery? They are very useful for grid storage applications as long as you can control the phase.
What makes you think that component is a capacitor? I'm assuming you drew the schematic.
The second image in the link shows a brown disk, which I thought was a ceramic capacitor. Looks like it's to stop a busted battery from being overcharged when a cell has died.
It won't do that. It is simply a fuse that prevents too high a current from flowing, such as if you connected the battery backwards.
I'm not sure what this circuit is supposed to do. It doesn't look right to me.It's the (5 hour) charger for a very cheap cordless drill. The input is a 14.4V wall wart. The output is to a pack of NiCad cells. It's worked fine for years, until I can no longer find replacement NiCad cells, so I'm converting the battery
on the right, the resistor to the right of that and the diode across the two. The two resistors and the green LED probably should be on the left, where power comes in. That's all they do is indicate the presence of power.It will be limited by the wall wart, which is a basic transformer and diodes. Since it's a 5 hour charge, it won't harm the battery to just keep going.
My point is this circuit isn't setting the voltage or limiting current other than through the fuse.
It appears to be a couple of LEDs that indicate the battery is charging and/or has power.Yes, the battery is basically just charged through the diode and fuse.
The diode will prevent the transistor from ever turning on more than a tiny amount, but with the gain of the transistor the red LED is turned on with a small current in the transistor BE path. It could be more clear if you redraw it with the base
going to push some unreasonable current though the power pack, so the fuse is needed.Yes, so why have the semiconductor fuse at all?Yeah it was just a quick sketch to try to understand it.
In any event, it is the wall wart that would seem to be doing all the work of charging the battery, setting the max current and the max voltage just by having a significant series resistance most likely.Ah, you beat me to it.
That's why the fuse is not needed for a shorted cell. Being at 11V instead of 14V isn't enough to make the current jump so much. A short or reversed battery is a different matter.Unless NiCads are vastly different to car batteries, one shorted cell makes a hell of a lot more current flow.
THE WALL WART LIMITS THE CURRENT AND PREVENTS ANY ISSUES FROM A SINGLE SHORTED CELL.
Is that clear?
[other groups reinstated to stop you limiting the audience - others may be reading this in another group]
Oh, you use google groups. My god man get a newsreader program.
As I said, when you reverse connect the battery, you double the voltage in the circuit. Rather than having a difference of a couple of volts in the EMF opposing the current, you now have a voltage that is perhaps 10 times that total. Yeah, that's
Exactly which quirks where those?
https://imgur.com/a/b8l5qKQ
Look at the circuit diagram. The positive of the battery is only
connected through a capacitor. How can a capacitor possibly pass DC
current to allow the battery to charge?
On Sun, 13 Feb 2022 20:33:34 -0000, "Commander Kinsey"
<CK1@nospam.com> wrote:
https://imgur.com/a/b8l5qKQ
Look at the circuit diagram. The positive of the battery is only connected through a capacitor. How can a capacitor possibly pass DC current to allow the battery to charge?
It can't. Maybe that yellow disk is not a capacitor.
On Sun, 13 Feb 2022 20:55:51 -0000, Rick C <gnuarm.deletethisbit@gmail.com> wrote:
On Sunday, February 13, 2022 at 3:33:49 PM UTC-5, Commander Kinsey wrote: >>> https://imgur.com/a/b8l5qKQ
Look at the circuit diagram. The positive of the battery is only connected through a capacitor. How can a capacitor possibly pass DC current to allow the battery to charge?
Maybe it's an AC battery? They are very useful for grid storage applications as long as you can control the phase.
What makes you think that component is a capacitor? I'm assuming you drew the schematic.
I've learned from someone on Quora that it's actually a PTC Fuse - a resettable semiconductor fuse.
The second image in the link shows a brown disk, which I thought was a ceramic capacitor. Looks like it's to stop a busted battery from being overcharged when a cell has died.
On Mon, 14 Feb 2022 00:54:02 -0000, williamwright
<wrightsaerials@f2s.com> wrote:
On 14/02/2022 00:47, Commander Kinsey wrote:
Unless NiCads are vastly different to car batteries, one shorted cell
makes a hell of a lot more current flow.
They are vastly different.
Do they not both have a very low internal resistance? Therefore
connecting a 10V battery to a 12V charger makes too much current flow?
https://imgur.com/a/b8l5qKQ
Look at the circuit diagram. The positive of the battery is only connected through a capacitor.
How can a capacitor possibly pass DC current to allow the battery to charge?
My guess is that schematic misinterprets the nature of the yellow
disc.
I suspect that it's not a capacitor at all, but is a
positive-temperature-coefficient thermistor - a "soft fuse".
Its called a lossless charger. I encountered something like it in an old pifco charging circuit in a torch. From what I could see one rectifier one large capacitor and a small bleed resistor across the mains pins was all supposed to charge two flat Ni-cads, and it was fine until the capacitor got leaky, and the room filled with nasty smelling smoke.
I'm just guessing here, since I cannot see your circuit, but it used to be a very common practice for small rechargeable devices.
Brian
On 2/13/2022 5:33 PM, Commander Kinsey wrote:
On Sun, 13 Feb 2022 20:55:51 -0000, Rick C <gnuarm.deletethisbit@gmail.com> wrote:
On Sunday, February 13, 2022 at 3:33:49 PM UTC-5, Commander Kinsey wrote: >>>> https://imgur.com/a/b8l5qKQ
Look at the circuit diagram. The positive of the battery is only connected through a capacitor. How can a capacitor possibly pass DC current to allow the battery to charge?
Maybe it's an AC battery? They are very useful for grid storage applications as long as you can control the phase.
What makes you think that component is a capacitor? I'm assuming you drew the schematic.
I've learned from someone on Quora that it's actually a PTC Fuse - a resettable semiconductor fuse.
The second image in the link shows a brown disk, which I thought was a ceramic capacitor. Looks like it's to stop a busted battery from being overcharged when a cell has died.
The shape of the edge of the device,
hints that it is not a disc capacitor.
One reason for that, is the material the yellow
thing is dipped in, is a hell of a lot harder,
than the softer stuff used on the older disc caps.
The yellow material might be intended to be
flame proof or the like.
On 2/13/2022 5:33 PM, Commander Kinsey wrote:
On Sun, 13 Feb 2022 20:55:51 -0000, Rick C <gnuarm.deletethisbit@gmail.com> wrote:
On Sunday, February 13, 2022 at 3:33:49 PM UTC-5, Commander Kinsey wrote: >>>> https://imgur.com/a/b8l5qKQ
Look at the circuit diagram. The positive of the battery is only connected through a capacitor. How can a capacitor possibly pass DC current to allow the battery to charge?
Maybe it's an AC battery? They are very useful for grid storage applications as long as you can control the phase.
What makes you think that component is a capacitor? I'm assuming you drew the schematic.
I've learned from someone on Quora that it's actually a PTC Fuse - a resettable semiconductor fuse.
The second image in the link shows a brown disk, which I thought was a ceramic capacitor. Looks like it's to stop a busted battery from being overcharged when a cell has died.
The shape of the edge of the device,
hints that it is not a disc capacitor.
One reason for that, is the material the yellow
thing is dipped in, is a hell of a lot harder,
than the softer stuff used on the older disc caps.
The yellow material might be intended to be
flame proof or the like.
As a connoisseur of circuits, I bet you've already
made up your mind as to whether this circuit is a
good idea or a bad idea...
On Sunday, February 13, 2022 at 5:34:03 PM UTC-5, Commander Kinsey wrote:
On Sun, 13 Feb 2022 20:55:51 -0000, Rick C <gnuarm.del...@gmail.com> wrote: >> > On Sunday, February 13, 2022 at 3:33:49 PM UTC-5, Commander Kinsey wrote: >> >> https://imgur.com/a/b8l5qKQ
Look at the circuit diagram. The positive of the battery is only connected through a capacitor. How can a capacitor possibly pass DC current to allow the battery to charge?
Maybe it's an AC battery? They are very useful for grid storage applications as long as you can control the phase.
What makes you think that component is a capacitor? I'm assuming you drew the schematic.
I've learned from someone on Quora that it's actually a PTC Fuse - a resettable semiconductor fuse.
The second image in the link shows a brown disk, which I thought was a ceramic capacitor. Looks like it's to stop a busted battery from being overcharged when a cell has died.
It's also not exactly what I'd call a charger. It's more of a charging indicator
circuit. It takes DC input and puts it straight to the battery through a diode.
The rest is there apparently for the two LEDS that show power on and charging.
On Mon, 14 Feb 2022 15:13:04 -0800, dplatt@coop.radagast.org (Dave
Platt) wrote:
In article <op.1hjp1807mvhs6z@ryzen.lan>,
Commander Kinsey <CK1@nospam.com> wrote:
https://imgur.com/a/b8l5qKQ
Look at the circuit diagram. The positive of the battery is only connected through a capacitor.
How can a capacitor possibly pass DC current to allow the battery to charge?
I don't believe that it could.
My guess is that schematic misinterprets the nature of the yellow
disc. I suspect that it's not a capacitor at all, but is a
positive-temperature-coefficient thermistor - a "soft fuse". If the
output (to the battery) is accidentally short-circuited, the high
current flow through the PTC will cause it to heat up, increasing its
resistance, causing it to heat up even faster, causing its resistance
to increase even more... and thus limiting the current flow through
the short circuit. These PTCs usually have a "hold current" (which
they will allow to pass for an unlimited amount of time, at room
temperature) and a "trip current" which will heat them enough to cause
them to limit the current.
Since we don't have a profile view of this component and can't see
the markings, I can't tell for sure.
It is called "resonant charging" and the current is pulses - so it
DOES flow through the capacitors
see https://www.researchgate.net/publication/327260616/figure/download/fig2/AS:664444522733570@1535427327725/Lossless-Resonant-Charging-Circuit.png
Or it could be a TPS as described here:
A transformerless power supply (TPS) is basically just a voltage
divider that takes the 115 or 220 VAC from your wall and divides it
down to whatever voltage you want. If that voltage needs to be DC, it
is rectified through a few diodes, and maybe regulated to a maximum
voltage but we’ll get to that in a minute.
Normally, DC voltage dividers are made with a pair of resistors.
Combined, they define the current flowing through the path, and the
top resistor can then be chosen to drop the difference between the
input voltage and the desired output. If, in our case, that difference
is some one or two hundred volts, even if it only has to pass a few
tens of milliamps, that resistor is going to get hot fast.
A better component to use in the top of the divider is a capacitor,
with its reactance chosen to give the desired “resistance” at whatever the mains frequency is where you live. For example, say you want 25
milliamps out at 5 V, and you’re in America and need to drop 110 V. R
= V / I = 4,400 O. Using the reactance of a capacitor, that’s C = 1 /
(2 * pi * 60 Hz * 4400) = 0.6 µF. If you need more current, use a
larger capacitor, and vice-versa. It’s that easy!
A fully elaborated TPS design requires a few more parts. For safety,
and to limit inrush current, a fuse and a one-watt current-limiting
resistor on the input are a good idea. A large-value discharge
resistor in parallel with the reactive capacitor will keep it from
holding its high voltage and shocking you when the circuit is
unplugged.
see https://hackaday.com/2017/04/04/the-shocking-truth-about-transformerless-power-supplies/
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