Troll-feeding Senile Asshole Alert!...

On Mon, 14 Feb 2022 12:22:30 -0000, Paul <nospam@needed.invalid> wrote:

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.

It is shinier than the disk capacitors.

You say \"older\" - don\'t they make them anymore?
 
On Mon, 14 Feb 2022 13:41:10 -0000, trader_4 <trader4@optonline.net> wrote:

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.

Yeah, very cheap cordless drill, doesn\'t even have gears. It has hammer action, but at 550rpm that\'s ridiculous. Also can only do a few holes in bricks before the battery goes flat. Maybe it\'ll work better when I introduce the motor to Li Ion....
 
On Sun, 13 Feb 2022 20:33:34 -0000, Birdbrain Macaw (aka \"Commander Kinsey\",
\"James Wilkinson\", \"Steven Wanker\",\"Bruce Farquar\", \"Fred Johnson, etc.),
the pathological resident idiot and attention whore of all the uk ngs,
blathered again:

<FLUSH the subnormal sociopathic trolling attention whore\'s latest
attention-baiting sick bullshit unread again>

--
damduck-egg@yahoo.co.uk about Birdbrain Macaw\'s (now \"Commander Kinsey\" LOL)
trolling:
\"He is a well known attention seeking troll and every reply you
make feeds him.
Starts many threads most of which die quick as on the UK groups anyone
with sense Kill filed him ages ago which is why he now cross posts to
the US groups for a new audience.
This thread was unusual in that it derived and continued without him
to a large extent and his silly questioning is an attempt to get
noticed again.\"
MID: <be195d5jh0hktj054mvfu7ef9ap854mjdb@4ax.com>

--
ItsJoanNotJoann addressing Birdbrain Macaw\'s (now \"Commander Kinsey\" LOL):
\"You\'re an annoying troll and I\'m done with you and your
stupidity.\"
MID: <e39a6a7f-9677-4e78-a866-0590fe5bbc38@googlegroups.com>

--
AndyW addressing Birdbrain:
\"Troll or idiot?...
You have been presented with a viewpoint with information, reasoning,
historical cases, citations and references to back it up and wilfully
ignore all going back to your idea which has no supporting information.\"
MID: <KaToA.263621$g93.262397@fx10.am4>
 
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 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?
 
On Mon, 14 Feb 2022 09:47:41 +1100, 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?

The text on it, fuckwit.
 
On Sun, 13 Feb 2022 22:54:07 -0000, Phil Allison <pallison49@gmail.com> wrote:

Commander Kinsey wrote:
=====================

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.

** It\'s \"self resetting\".

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.

Those aren\'t shown in the pictures.

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.

One cell shorted, much higher current flows, duh. Now fuck off Rod.
 
On Sun, 13 Feb 2022 23:02:03 -0000, Rick C <gnuarm.deletethisbit@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:

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 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.

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.

> 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 LiIon.
 
On Mon, 14 Feb 2022 09:54:27 +1100, Rex Jones, better known as cantankerous
trolling senile geezer Rodent Speed, wrote:

<FLUSH the two subnormal sociopathic cretins\' endless absolutely idiotic
blather>

--
Another typical retarded \"conversation\" between the two resident idiots:

Birdbrain: \"But imagine how cool it was to own slaves.\"

Senile Rodent: \"Yeah, right. Feed them, clothe them, and fix them when
they\'re broken.
After all, you paid good money for them. Then you\'ve got to keep an eye
on them all the time.\"

Birdbrain: \"Better than having to give them wages on top of that.\"

Senile Rodent: \"Specially when they make more slaves for you
and produce their own food and clothes.\"

MID: <fvlcdcFq2icU1@mid.individual.net>
 
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.



--

I yam what I yam - Popeye
 
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.



--

I yam what I yam - Popeye
 
On Sun, 13 Feb 2022 23:59:33 -0000, <jlarkin@highlandsniptechnology.com> wrote:

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.

Not so easy when in the middle of a big circuit.
 
On Mon, 14 Feb 2022 00:10:47 -0000, Rick C <gnuarm.deletethisbit@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:
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 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.
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.
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 LiIon.

My point is this circuit isn\'t setting the voltage or limiting current other than through the fuse.

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 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 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 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.
 
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.

Bill
 
Commander Kinsey wrote:
=====================
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.

** FFS imbecile , YOU can see them !!!

===============================
 
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\"
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.
Not so easy when in the middle of a big circuit.

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.
 
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?
 
Commander Kinsey <CK1@nospam.com> wrote
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?

Nope. a stupid car battery charger like that one is essentially limiting
the current
so the battery voltage doesn\'t determine the current in the too much sense.
 
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 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:
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 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.
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.
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 LiIon.

My point is this circuit isn\'t setting the voltage or limiting current other than through the fuse.
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 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 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 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?

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.
 
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 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:
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 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.
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.
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 LiIon.

My point is this circuit isn\'t setting the voltage or limiting
current other than through the fuse.
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 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 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 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?

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.
 

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