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Groups > uk.tech.broadcast > #70556 > unrolled thread
| Started by | "J. P. Gilliver" <G6JPG@255soft.uk> |
|---|---|
| First post | 2026-09-26 19:08 +0100 |
| Last post | 2026-09-27 13:12 +0200 |
| Articles | 20 on this page of 127 — 23 participants |
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Re: OT - TV "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-26 19:08 +0100
Re: OT - TV Scott <newsgroups@gefion.myzen.co.uk> - 2026-09-26 19:58 +0100
Re: OT - TV "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-26 20:30 +0100
Re: OT - TV liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-09-27 09:39 +0100
Re: OT - TV JMB99 <mb@nospam.net> - 2026-09-28 08:08 +0100
Re: OT - TV Frank Slootweg <this@ddress.is.invalid> - 2026-09-26 19:10 +0000
Re: OT - TV "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-26 21:02 +0100
Re: OT - TV "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-26 21:03 +0100
Re: OT - TV Frank Slootweg <this@ddress.is.invalid> - 2026-09-27 18:20 +0000
Re: OT - TV "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-28 16:26 +0100
Re: OT - TV Frank Slootweg <this@ddress.is.invalid> - 2026-09-28 15:45 +0000
Re: OT - TV Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2026-09-28 16:30 +0000
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-09-28 17:46 +0100
Re: OT - TV "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-28 22:25 +0100
Re: OT - TV NY <me@privacy.net> - 2026-09-29 16:40 +0100
OT - Lehrer (was: Re: OT - TV) "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-29 16:58 +0100
Re: OT - Lehrer (was: Re: OT - TV) Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2026-09-29 18:19 +0000
Re: OT - Lehrer "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-29 20:57 +0100
Re: OT - Lehrer Charles Hope <clh@candehope.me.uk> - 2026-09-29 20:00 +0000
Re: OT - Lehrer (was: Re: OT - TV) André Coutanche <acoutanche@gmx.co.uk> - 2026-09-29 21:50 +0100
Re: OT - Lehrer NY <me@privacy.net> - 2026-09-29 22:33 +0100
Re: OT - Lehrer Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2026-09-29 22:48 +0000
Re: OT - Lehrer "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-30 01:07 +0100
Re: OT - Lehrer John Ames <commodorejohn@gmail.com> - 2026-09-30 15:51 -0700
Re: OT - Lehrer NY <me@privacy.net> - 2026-10-01 10:57 +0100
Re: OT - Lehrer NY <me@privacy.net> - 2026-09-30 08:10 +0100
Re: OT - Lehrer "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-30 01:39 +0100
Re: OT - Lehrer Roger Blake <rogblake@iname.invalid> - 2026-09-30 00:46 +0000
Re: OT - Lehrer NY <me@privacy.net> - 2026-09-29 22:39 +0100
Re: OT - Lehrer Frank Slootweg <this@ddress.is.invalid> - 2026-09-30 12:25 +0000
Re: OT - Lehrer "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-30 13:34 +0100
Re: OT - Lehrer The Natural Philosopher <tnp@invalid.invalid> - 2026-09-30 14:31 +0100
Re: OT - Lehrer NY <me@privacy.net> - 2026-09-30 14:47 +0100
Re: OT - Lehrer John Williamson <johnwilliamson@btinternet.com> - 2026-09-30 14:58 +0100
Re: OT - Lehrer "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-10-01 02:36 +0100
Re: OT - Lehrer NY <me@privacy.net> - 2026-10-01 11:12 +0100
Re: OT - Lehrer Frank Slootweg <this@ddress.is.invalid> - 2026-10-01 14:35 +0000
Re: OT - Lehrer NY <me@privacy.net> - 2026-10-01 16:14 +0100
Re: OT - Lehrer Frank Slootweg <this@ddress.is.invalid> - 2026-10-01 17:35 +0000
Re: OT - Lehrer Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2026-10-01 17:53 +0000
Re: OT - Lehrer John Williamson <johnwilliamson@btinternet.com> - 2026-10-01 19:03 +0100
Re: OT - Lehrer "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-10-01 21:50 +0100
Re: OT - Lehrer The Natural Philosopher <tnp@invalid.invalid> - 2026-10-02 12:25 +0100
Re: OT - Lehrer The Natural Philosopher <tnp@invalid.invalid> - 2026-10-01 11:13 +0100
Re: OT - Lehrer NY <me@privacy.net> - 2026-10-01 11:51 +0100
Re: OT - Lehrer John Williamson <johnwilliamson@btinternet.com> - 2026-09-30 14:55 +0100
Re: OT - Lehrer Charles Hope <clh@candehope.me.uk> - 2026-09-30 14:15 +0000
Re: OT - TV Daniel70 <daniel47@nomail.afraid.org> - 2026-09-27 19:58 +1000
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-09-27 12:52 +0100
Re: OT - TV Daniel70 <daniel47@nomail.afraid.org> - 2026-09-27 22:13 +1000
[OT] - audio distribution, Rediffusion-style (was: Re: OT - TV) "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-28 16:43 +0100
Re: OT - TV Max Demian <max_demian@bigfoot.com> - 2026-09-27 11:44 +0100
Re: OT - TV "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-27 16:12 +0100
Re: OT - TV Max Demian <max_demian@bigfoot.com> - 2026-09-27 18:12 +0100
Re: OT - TV Andy Burns <usenet@andyburns.uk> - 2026-09-27 18:23 +0100
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-09-27 18:34 +0100
Re: OT - TV Max Demian <max_demian@bigfoot.com> - 2026-09-28 14:03 +0100
Re: OT - TV liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-09-28 15:56 +0100
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-09-28 16:46 +0100
Re: OT - TV liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-09-28 17:16 +0100
Re: OT - TV Max Demian <max_demian@bigfoot.com> - 2026-09-29 12:01 +0100
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-09-29 13:05 +0100
Re: OT - TV liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-09-29 13:25 +0100
Re: OT - TV "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-29 14:13 +0100
Re: OT - TV The Other John <nomail@here.org> - 2026-09-29 16:53 +0100
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-09-29 17:12 +0100
Re: OT - TV liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-09-30 10:22 +0100
Re: OT - TV "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-30 13:36 +0100
Re: OT - TV "Carlos E.R." <robin_listas@es.invalid> - 2026-09-30 11:23 +0200
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-09-30 11:48 +0100
Re: OT - TV Paul <nospam@needed.invalid> - 2026-09-30 07:37 -0400
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-09-30 14:28 +0100
Re: OT - TV "Carlos E. R." <robin_listas@es.invalid> - 2026-10-01 00:35 +0200
Re: OT - TV "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-10-01 02:15 +0100
Re: OT - TV Paul <nospam@needed.invalid> - 2026-10-01 00:15 -0400
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-10-01 12:50 +0100
Re: OT - TV "Carlos E. R." <robin_listas@es.invalid> - 2026-10-01 14:24 +0200
Re: OT - TV Max Demian <max_demian@bigfoot.com> - 2026-10-01 17:17 +0100
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-10-01 12:48 +0100
Re: OT - TV liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-10-01 13:10 +0100
Re: OT - TV John Williamson <johnwilliamson@btinternet.com> - 2026-10-01 13:42 +0100
Re: OT - TV John Williamson <johnwilliamson@btinternet.com> - 2026-10-01 13:32 +0100
Re: OT - TV Frank Slootweg <this@ddress.is.invalid> - 2026-10-01 14:52 +0000
Re: OT - TV Daniel70 <daniel47@nomail.afraid.org> - 2026-10-03 21:10 +1000
Re: OT - TV "Carlos E. R." <robin_listas@es.invalid> - 2026-10-03 13:39 +0200
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-10-03 12:47 +0100
Re: OT - TV John Williamson <johnwilliamson@btinternet.com> - 2026-10-03 12:50 +0100
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-10-03 13:09 +0100
Re: OT - TV John Williamson <johnwilliamson@btinternet.com> - 2026-10-03 15:59 +0100
Re: OT - TV Jan Panteltje <alien@comet.invalid> - 2026-10-03 15:56 +0000
Re: OT - TV John Williamson <johnwilliamson@btinternet.com> - 2026-10-03 17:19 +0100
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-10-03 18:41 +0100
Re: OT - TV "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-10-03 22:52 +0100
Re: OT - TV Paul <nospam@needed.invalid> - 2026-10-03 21:24 -0400
Re: OT - TV Roderick Stewart <rjfs@escapetime.myzen.co.uk> - 2026-09-30 15:13 +0100
Re: OT - TV liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-09-29 13:16 +0100
Re: OT - TV Jan Panteltje <alien@comet.invalid> - 2026-09-29 15:54 +0000
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-09-29 17:15 +0100
Re: OT - TV "Carlos E.R." <robin_listas@es.invalid> - 2026-09-30 11:27 +0200
Re: OT - TV John Williamson <johnwilliamson@btinternet.com> - 2026-09-30 11:13 +0100
Re: OT - TV John Williamson <johnwilliamson@btinternet.com> - 2026-09-30 11:19 +0100
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-09-30 11:57 +0100
Re: OT - TV liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-09-30 13:29 +0100
Re: OT - TV John Williamson <johnwilliamson@btinternet.com> - 2026-09-30 13:54 +0100
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-09-30 14:34 +0100
Re: OT - TV liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-09-30 18:08 +0100
Re: OT - TV "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-10-01 02:22 +0100
Re: OT - TV Jan Panteltje <alien@comet.invalid> - 2026-10-01 06:37 +0000
Re: OT - TV liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-10-01 10:32 +0100
Re: OT - TV liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-10-01 09:41 +0100
Re: OT - TV "Carlos E. R." <robin_listas@es.invalid> - 2026-10-01 00:37 +0200
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-09-30 11:50 +0100
Re: OT - TV Jan Panteltje <alien@comet.invalid> - 2026-09-30 13:08 +0000
Re: OT - TV "Carlos E. R." <robin_listas@es.invalid> - 2026-10-01 00:50 +0200
Re: OT - TV Jan Panteltje <alien@comet.invalid> - 2026-10-01 06:12 +0000
Re: OT - TV c186282 <c186282@nnada.net> - 2026-10-01 03:29 -0400
Re: OT - TV "Carlos E. R." <robin_listas@es.invalid> - 2026-10-01 14:53 +0200
Re: OT - TV Paul <nospam@needed.invalid> - 2026-10-01 03:32 -0400
Re: OT - TV "Carlos E. R." <robin_listas@es.invalid> - 2026-10-01 14:49 +0200
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-10-01 12:57 +0100
Re: OT - TV liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-10-01 13:27 +0100
Re: OT - TV "Carlos E. R." <robin_listas@es.invalid> - 2026-10-01 15:19 +0200
Re: OT - TV Jan Panteltje <alien@comet.invalid> - 2026-10-01 14:34 +0000
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-10-01 15:51 +0100
Re: OT - TV Jan Panteltje <alien@comet.invalid> - 2026-10-02 06:52 +0000
Re: OT - TV Andy Burns <usenet@andyburns.uk> - 2026-10-04 07:52 +0100
Re: OT - TV "Carlos E.R." <robin_listas@es.invalid> - 2026-09-27 13:12 +0200
Page 5 of 7 — ← Prev page 1 2 3 4 [5] 6 7 Next page →
| From | John Williamson <johnwilliamson@btinternet.com> |
|---|---|
| Date | 2026-10-01 13:42 +0100 |
| Message-ID | <ni72pdFs3m5U1@mid.individual.net> |
| In reply to | #70665 |
On 01/10/2026 13:10, Liz Tuddenham wrote: > The Natural Philosopher <tnp@invalid.invalid> wrote: > >> On 30/09/2026 23:35, Carlos E. R. wrote: >>> On 2026-09-30 15:28, The Natural Philosopher wrote: >>>> On 30/09/2026 12:37, Paul wrote: >>>>> On Wed, 9/30/2026 5:23 AM, Carlos E.R. wrote: >>> >>> >>>> Automotive is 13.8V rated and that/s it. The alternators wont go >>>> higher. Which is why you use bridged amps >>> >>> I have seen 15 volts. >>> >>> >> The absolute max is supposed to be 14,4 > > That's the generally-accepted stabilised voltage for not over-charging > the battery but fast chargers and dynamo-driven systems can often exceed > that. Loose battery terminals can cause the regulator to overshoot and > inductive loads can generate very large spikes with a lot of stored > energy. > > For boats, we are now using Lithium Iron Phosphate batteries, which unlike lead acid, will accept the full charge current until the battery management system disconnects the charge source to avoid damaging the cells. This sudden disconnection causes the windings in the alternator to generate a spike which can easily destroy the rectifier diodes and regulator electronics. The spike contains tens of joules of energy, so can reach over 100 Volts depending on the other loads. For this reason, we always connect a lead acid battery to the alternator and use a DC-DC converter to charge the PiFePO4 batteries. -- Tciao for Now! John.
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| From | John Williamson <johnwilliamson@btinternet.com> |
|---|---|
| Date | 2026-10-01 13:32 +0100 |
| Message-ID | <ni7271Fs13aU1@mid.individual.net> |
| In reply to | #70644 |
On 30/09/2026 23:35, Carlos E. R. wrote: > On 2026-09-30 15:28, The Natural Philosopher wrote: >> On 30/09/2026 12:37, Paul wrote: >>> On Wed, 9/30/2026 5:23 AM, Carlos E.R. wrote: > > >> Automotive is 13.8V rated and that/s it. The alternators wont go >> higher. Which is why you use bridged amps > > I have seen 15 volts. > > Both the alternators I currently have in use go to 14.5 volts, as did the dynamo on the Land Rover.. All amps for Auto use are rated for slightly more than the alternator voltage for safety, and for really high power, require very low speaker impedances. The one on my boat is rated for full power into a 1 ohm load. -- Tciao for Now! John.
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| From | Frank Slootweg <this@ddress.is.invalid> |
|---|---|
| Date | 2026-10-01 14:52 +0000 |
| Message-ID | <119m338.o7c.1@ID-201911.user.individual.net> |
| In reply to | #70644 |
Carlos E. R. <robin_listas@es.invalid> wrote: > On 2026-09-30 15:28, The Natural Philosopher wrote: > > On 30/09/2026 12:37, Paul wrote: > >> On Wed, 9/30/2026 5:23 AM, Carlos E.R. wrote: > > > > Automotive is 13.8V rated and that/s it. The alternators wont go > > higher. Which is why you use bridged amps > > I have seen 15 volts. Yes, I see that as well, or values very close to 15V. The battery tester [1] I have, has a 'Good' range from 13.4-14.8V (with the engine running, i.e. the alternator providing power). [1] A simple one, plugged into the 'cigarette lighter' socket.
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| From | Daniel70 <daniel47@nomail.afraid.org> |
|---|---|
| Date | 2026-10-03 21:10 +1000 |
| Message-ID | <119qnr6$2urls$1@dont-email.me> |
| In reply to | #70676 |
On 2/10/2026 12:52 am, Frank Slootweg wrote: > Carlos E. R. <robin_listas@es.invalid> wrote: >> On 2026-09-30 15:28, The Natural Philosopher wrote: >>> On 30/09/2026 12:37, Paul wrote: >>>> On Wed, 9/30/2026 5:23 AM, Carlos E.R. wrote: >> >>> Automotive is 13.8V rated and that/s it. The alternators wont go >>> higher. Which is why you use bridged amps >> >> I have seen 15 volts. > > Yes, I see that as well, or values very close to 15V. > > The battery tester [1] I have, has a 'Good' range from 13.4-14.8V > (with the engine running, i.e. the alternator providing power). > > [1] A simple one, plugged into the 'cigarette lighter' socket. > (Not being very mechanically minded, myself but) I've thought for a long, long time that Battery Cells were 2.2Volts each so the six cells in a Car Battery gives 13.2Volts. When recharging a Battery, you want to apply a slightly higher Voltage ... (as the Battery will pull the charger Voltage down) so 13.4Volts up to about 14Volts would probably do the job well enough, although charging the Battery may take a while longer. 15Volts might cook the Battery. -- Daniel70
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| From | "Carlos E. R." <robin_listas@es.invalid> |
|---|---|
| Date | 2026-10-03 13:39 +0200 |
| Message-ID | <nic7s4Fk2g3U3@mid.individual.net> |
| In reply to | #70693 |
On 2026-10-03 13:10, Daniel70 wrote:
> On 2/10/2026 12:52 am, Frank Slootweg wrote:
>> Carlos E. R. <robin_listas@es.invalid> wrote:
>>> On 2026-09-30 15:28, The Natural Philosopher wrote:
>>>> On 30/09/2026 12:37, Paul wrote:
>>>>> On Wed, 9/30/2026 5:23 AM, Carlos E.R. wrote:
>>>
>>>> Automotive is 13.8V rated and that/s it. The alternators wont go
>>>> higher. Which is why you use bridged amps
>>>
>>> I have seen 15 volts.
>>
>> Yes, I see that as well, or values very close to 15V.
>>
>> The battery tester [1] I have, has a 'Good' range from 13.4-14.8V
>> (with the engine running, i.e. the alternator providing power).
>>
>> [1] A simple one, plugged into the 'cigarette lighter' socket.
>>
> (Not being very mechanically minded, myself but) I've thought for a
> long, long time that Battery Cells were 2.2Volts each so the six cells
> in a Car Battery gives 13.2Volts.
>
> When recharging a Battery, you want to apply a slightly higher
> Voltage ... (as the Battery will pull the charger Voltage down) so
> 13.4Volts up to about 14Volts would probably do the job well enough,
> although charging the Battery may take a while longer.
>
> 15Volts might cook the Battery.
They use voltages going to 30 volts to fast charge a battery. I'm not
sure of the exact figures, but I saw them once in the wikipedia.
--
Cheers,
Carlos E.R.
ES🇪🇸, EU🇪🇺.
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| From | The Natural Philosopher <tnp@invalid.invalid> |
|---|---|
| Date | 2026-10-03 12:47 +0100 |
| Message-ID | <119qq1d$2vglb$1@dont-email.me> |
| In reply to | #70693 |
On 03/10/2026 12:10, Daniel70 wrote: > (Not being very mechanically minded, myself but) I've thought for a > long, long time that Battery Cells were 2.2Volts each so the six cells > in a Car Battery gives 13.2Volts. > Nominal *fully charged* voltage is 13.4V, I think charging voltage is generally around 14.4V > When recharging a Battery, you want to apply a slightly higher Voltage > ... (as the Battery will pull the charger Voltage down) so 13.4Volts up > to about 14Volts would probably do the job well enough, although > charging the Battery may take a while longer. > > 15Volts might cook the Battery. Its unlikely that the alternator could supply enough current to raise it that high -- “Politics is the art of looking for trouble, finding it everywhere, diagnosing it incorrectly and applying the wrong remedies.” ― Groucho Marx
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| From | John Williamson <johnwilliamson@btinternet.com> |
|---|---|
| Date | 2026-10-03 12:50 +0100 |
| Message-ID | <nic8gsFlgotU1@mid.individual.net> |
| In reply to | #70693 |
On 03/10/2026 12:10, Daniel70 wrote: > On 2/10/2026 12:52 am, Frank Slootweg wrote: >> Carlos E. R. <robin_listas@es.invalid> wrote: >>> On 2026-09-30 15:28, The Natural Philosopher wrote: >>>> On 30/09/2026 12:37, Paul wrote: >>>>> On Wed, 9/30/2026 5:23 AM, Carlos E.R. wrote: >>> >>>> Automotive is 13.8V rated and that/s it. The alternators wont go >>>> higher. Which is why you use bridged amps >>> >>> I have seen 15 volts. >> >> Yes, I see that as well, or values very close to 15V. >> >> The battery tester [1] I have, has a 'Good' range from 13.4-14.8V >> (with the engine running, i.e. the alternator providing power). >> >> [1] A simple one, plugged into the 'cigarette lighter' socket. >> > (Not being very mechanically minded, myself but) I've thought for a > long, long time that Battery Cells were 2.2Volts each so the six cells > in a Car Battery gives 13.2Volts. > The voltage of a lead acid cell varies between 1.93 volts when flat and 2.11 volts when fully charged. It can rise to 2.33 volts while on charge. This translates to the voltage at the lighter socket being anywhere between 11.8 and 14.4 Volts. When the engine is running, it normally will be about 14.4 volts. 13.2 volts is a safe voltage to hold the battery at while on float charge. (The battery is being used as a backup supply in case of mains failure.) > When recharging a Battery, you want to apply a slightly higher Voltage > ... (as the Battery will pull the charger Voltage down) so 13.4Volts up > to about 14Volts would probably do the job well enough, although > charging the Battery may take a while longer. > > 15Volts might cook the Battery. On occasion, 15 Volt or slightly more can be used ro equalise the charge between the cells, but this will cause some of the water in the electrolyte to split into hydrogen and oxygen. -- Tciao for Now! John.
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| From | The Natural Philosopher <tnp@invalid.invalid> |
|---|---|
| Date | 2026-10-03 13:09 +0100 |
| Message-ID | <119qr92$2vglb$2@dont-email.me> |
| In reply to | #70696 |
On 03/10/2026 12:50, John Williamson wrote: > On occasion, 15 Volt or slightly more can be used ro equalise the charge > between the cells, but this will cause some of the water in the > electrolyte to split into hydrogen and oxygen. And some of the cells to split into plastic, lead, acid and a loud bang DAMHIKT... -- “The urge to save humanity is almost always only a false face for the urge to rule it.” – H. L. Mencken
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| From | John Williamson <johnwilliamson@btinternet.com> |
|---|---|
| Date | 2026-10-03 15:59 +0100 |
| Message-ID | <nicjicFn3jhU1@mid.individual.net> |
| In reply to | #70697 |
On 03/10/2026 13:09, The Natural Philosopher wrote: > On 03/10/2026 12:50, John Williamson wrote: >> On occasion, 15 Volt or slightly more can be used ro equalise the >> charge between the cells, but this will cause some of the water in the >> electrolyte to split into hydrogen and oxygen. > And some of the cells to split into plastic, lead, acid and a loud bang > DAMHIKT... That needs a spark nearby -- Tciao for Now! John.
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| From | Jan Panteltje <alien@comet.invalid> |
|---|---|
| Date | 2026-10-03 15:56 +0000 |
| Message-ID | <119r8k4$3515t$1@dont-email.me> |
| In reply to | #70699 |
>John Williamson <johnwilliamson@btinternet.com>wrote: >>On 03/10/2026 13:09, The Natural Philosopher wrote: >> On 03/10/2026 12:50, John Williamson wrote: >>> On occasion, 15 Volt or slightly more can be used ro equalise the >>> charge between the cells, but this will cause some of the water in the >>> electrolyte to split into hydrogen and oxygen. >> And some of the cells to split into plastic, lead, acid and a loud bang >> DAMHIKT... > >That needs a spark nearby I was just charging a lead acid battery (from a UPS) with my lab supply: https://ibb.co/j9hGGcNB You can set voltage and current-limit anyway you want Very useful thing, designed and build it around 2010: https://panteltje.nl/panteltje/pic/pwr_pic/ You can charge all sort of batteries with it. 12 V in from a big wallwart (from mains) 0 to 24 V adjustable output.
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| From | John Williamson <johnwilliamson@btinternet.com> |
|---|---|
| Date | 2026-10-03 17:19 +0100 |
| Message-ID | <nico85FnpicU1@mid.individual.net> |
| In reply to | #70700 |
On 03/10/2026 16:56, Jan Panteltje wrote: >> John Williamson <johnwilliamson@btinternet.com>wrote: >>> On 03/10/2026 13:09, The Natural Philosopher wrote: >>> On 03/10/2026 12:50, John Williamson wrote: >>>> On occasion, 15 Volt or slightly more can be used ro equalise the >>>> charge between the cells, but this will cause some of the water in the >>>> electrolyte to split into hydrogen and oxygen. >>> And some of the cells to split into plastic, lead, acid and a loud bang >>> DAMHIKT... >> >> That needs a spark nearby > > I was just charging a lead acid battery (from a UPS) with my lab supply: > https://ibb.co/j9hGGcNB > > You can set voltage and current-limit anyway you want > > Very useful thing, designed and build it around 2010: > https://panteltje.nl/panteltje/pic/pwr_pic/ > > You can charge all sort of batteries with it. > 12 V in from a big wallwart (from mains) 0 to 24 V adjustable output. > I use 12 volts at home to power all sorts of things, and for many years, I used lead acid batteries. I now use Lithium Iron Phosphate batteries. (I live on a boat) The batteries get changed by solar power, the engine alternator or a mains powered charger. I have a number of DC-DC converters to power laptops and such and an inverter which can power a microwave or power tools. -- Tciao for Now! John.
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| From | The Natural Philosopher <tnp@invalid.invalid> |
|---|---|
| Date | 2026-10-03 18:41 +0100 |
| Message-ID | <119reoe$37dqq$1@dont-email.me> |
| In reply to | #70699 |
On 03/10/2026 15:59, John Williamson wrote: > On 03/10/2026 13:09, The Natural Philosopher wrote: >> On 03/10/2026 12:50, John Williamson wrote: >>> On occasion, 15 Volt or slightly more can be used ro equalise the >>> charge between the cells, but this will cause some of the water in the >>> electrolyte to split into hydrogen and oxygen. >> And some of the cells to split into plastic, lead, acid and a loud bang >> DAMHIKT... > > That needs a spark nearby > Yes. Removing the battery charger was plenty. -- Microsoft : the best reason to go to Linux that ever existed.
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| From | "J. P. Gilliver" <G6JPG@255soft.uk> |
|---|---|
| Date | 2026-10-03 22:52 +0100 |
| Message-ID | <119rtfl$3cufj$1@dont-email.me> |
| In reply to | #70696 |
On 2026/10/3 12:50:51, John Williamson wrote: [] > On occasion, 15 Volt or slightly more can be used ro equalise the charge > between the cells, but this will cause some of the water in the > electrolyte to split into hydrogen and oxygen. > > Which won't recombine (except explosively), so reducing the amount of electrolyte in the gassing cell, so reducing the capacity - which will thus cause that cell to be the first to start gassing next time, i. e. (slow) positive feedback. Whether this can be remedied by topping up the affected cell(s), I do not know. -- J. P. Gilliver. UMRA: 1960/<1985 MB++G()ALIS-Ch++(p)Ar++T+H+Sh0!:`)DNAf
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| From | Paul <nospam@needed.invalid> |
|---|---|
| Date | 2026-10-03 21:24 -0400 |
| Message-ID | <119s9s8$3gl64$1@dont-email.me> |
| In reply to | #70703 |
On Sat, 10/3/2026 5:52 PM, J. P. Gilliver wrote: > On 2026/10/3 12:50:51, John Williamson wrote: > [] >> On occasion, 15 Volt or slightly more can be used ro equalise the charge >> between the cells, but this will cause some of the water in the >> electrolyte to split into hydrogen and oxygen. >> >> > Which won't recombine (except explosively), so reducing the amount of > electrolyte in the gassing cell, so reducing the capacity - which will > thus cause that cell to be the first to start gassing next time, i. e. > (slow) positive feedback. Whether this can be remedied by topping up the > affected cell(s), I do not know. > "The Basic Chemistry of Gas Recombination in Lead-Acid Batteries" https://www.tms.org/pubs/journals/jom/0101/nelson-0101.html It appears the process takes care of the oxygen. Paul
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| From | Roderick Stewart <rjfs@escapetime.myzen.co.uk> |
|---|---|
| Date | 2026-09-30 15:13 +0100 |
| Message-ID | <iv5qbltcnrg3t63mdjnbqdlrmn4vmrvorr@4ax.com> |
| In reply to | #70620 |
On Wed, 30 Sep 2026 11:23:21 +0200, "Carlos E.R." <robin_listas@es.invalid> wrote: >> Its NOT juts a matter of impedance - its a matter of DC bias. You cannot >> build a >> valve amplifier that delivers true AC without an isolation transformer. >> Loudspeakers don't like DC bias > >That's true also for transistors, and we don't normally use >transformers. We use capacitors. You don't need an isolating capacitor in the output of a transistor amplifier if it has a +/- power supply so that the output voltage has a DC component of zero. You still need big capacitors, but audio isn't going through them because they're smoothing the DC supply instead. Rod.
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| From | liz@poppyrecords.invalid.invalid (Liz Tuddenham) |
|---|---|
| Date | 2026-09-29 13:16 +0100 |
| Message-ID | <1s278ix.1exku2ij8p4zkN%liz@poppyrecords.invalid.invalid> |
| In reply to | #70594 |
Max Demian <max_demian@bigfoot.com> wrote: > On 28/09/2026 16:46, The Natural Philosopher wrote: > > On 28/09/2026 14:03, Max Demian wrote: > >> Yes, I suppose there could be a matching transformer, in the same way > >> that there were boxes you connected to the "extension speaker" socket > >> of the main (valve) radio so you could listen in the kitchen. I had > >> one which had a transformer and a wander plug arrangement so you could > >> match it. Some valve radios had a high impedance output, so presumably > >> both connections would be at (more or less) HT voltage above the radio > >> chassis (which would be earth if the earth socket was connected). I > >> think there were high impedance horn extension speakers at one time. > > > Valve amps ALWAYS have an output transformer. Not least because there > > are no 'P channel ' valves. > > I think there were high impedance horn speakers, which wouldn't require > a transformer. And, of course, high impedance headphones if you don't > want a loudspeaker. The moving-iron loudspeakers were higher impedance and could be connected directly into the anode circuit of a valve but the sound quality was much poorer than a moving coil loudspeaker. Some used a large paper diaphragm, others used a small metal diaphragm with a horn for acoustic impedance matching. Some early horn loudspeakers were little more than a high-impedance earphone joined to a horn. Most post-1930s horn loudspeakers have a low impedance moving coil drive unit and some have a matching transformer built into the back of the housing. Eddystone communication receivers still had a separate high impedance headphone socket, in addition to loudspeaker connections, right up to the last valve models. -- ~ Liz Tuddenham ~ (Remove the ".invalid"s and add ".co.uk" to reply) www.poppyrecords.co.uk
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| From | Jan Panteltje <alien@comet.invalid> |
|---|---|
| Date | 2026-09-29 15:54 +0000 |
| Message-ID | <119gmur$3e4ln$1@dont-email.me> |
| In reply to | #70594 |
>Max Demian <max_demian@bigfoot.com>wrote: >>On 28/09/2026 16:46, The Natural Philosopher wrote: >> On 28/09/2026 14:03, Max Demian wrote: >>> Yes, I suppose there could be a matching transformer, in the same way >>> that there were boxes you connected to the "extension speaker" socket >>> of the main (valve) radio so you could listen in the kitchen. I had >>> one which had a transformer and a wander plug arrangement so you could >>> match it. Some valve radios had a high impedance output, so presumably >>> both connections would be at (more or less) HT voltage above the radio >>> chassis (which would be earth if the earth socket was connected). I >>> think there were high impedance horn extension speakers at one time. > >> Valve amps ALWAYS have an output transformer. Not least because there >> are no 'P channel ' valves. > >I think there were high impedance horn speakers, which wouldn't require >a transformer. And, of course, high impedance headphones if you don't >want a loudspeaker. Yes some tube TVs had 800 Ohm speakers without transformers. Example of a tube output stage without transformer to drive a 800 Ohm speaker: https://2.bp.blogspot.com/-GaJkZ9klfLw/VOecHjVgPuI/AAAAAAAAA4g/H2qcMWJ3tuA/s1600/Schema.png
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| From | The Natural Philosopher <tnp@invalid.invalid> |
|---|---|
| Date | 2026-09-29 17:15 +0100 |
| Message-ID | <119go7i$3cdrk$3@dont-email.me> |
| In reply to | #70602 |
On 29/09/2026 16:54, Jan Panteltje wrote: >> Max Demian <max_demian@bigfoot.com>wrote: >>> On 28/09/2026 16:46, The Natural Philosopher wrote: >>> On 28/09/2026 14:03, Max Demian wrote: >>>> Yes, I suppose there could be a matching transformer, in the same way >>>> that there were boxes you connected to the "extension speaker" socket >>>> of the main (valve) radio so you could listen in the kitchen. I had >>>> one which had a transformer and a wander plug arrangement so you could >>>> match it. Some valve radios had a high impedance output, so presumably >>>> both connections would be at (more or less) HT voltage above the radio >>>> chassis (which would be earth if the earth socket was connected). I >>>> think there were high impedance horn extension speakers at one time. >> >>> Valve amps ALWAYS have an output transformer. Not least because there >>> are no 'P channel ' valves. >> >> I think there were high impedance horn speakers, which wouldn't require >> a transformer. And, of course, high impedance headphones if you don't >> want a loudspeaker. > > Yes some tube TVs had 800 Ohm speakers without transformers. > > Example of a tube output stage without transformer to drive a 800 Ohm speaker: > https://2.bp.blogspot.com/-GaJkZ9klfLw/VOecHjVgPuI/AAAAAAAAA4g/H2qcMWJ3tuA/s1600/Schema.png STAGGERINGLY inefficient circuit, but yes, it works. -- The urge to save humanity is almost always a false front for the urge to rule. – H. L. Mencken, American journalist, 1880-1956
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| From | "Carlos E.R." <robin_listas@es.invalid> |
|---|---|
| Date | 2026-09-30 11:27 +0200 |
| Message-ID | <j91vomxksl.ln2@Telcontar.valinor> |
| In reply to | #70602 |
On 2026-09-29 17:54, Jan Panteltje wrote: >> Max Demian <max_demian@bigfoot.com>wrote: >>> On 28/09/2026 16:46, The Natural Philosopher wrote: >>> On 28/09/2026 14:03, Max Demian wrote: >>>> Yes, I suppose there could be a matching transformer, in the same way >>>> that there were boxes you connected to the "extension speaker" socket >>>> of the main (valve) radio so you could listen in the kitchen. I had >>>> one which had a transformer and a wander plug arrangement so you could >>>> match it. Some valve radios had a high impedance output, so presumably >>>> both connections would be at (more or less) HT voltage above the radio >>>> chassis (which would be earth if the earth socket was connected). I >>>> think there were high impedance horn extension speakers at one time. >> >>> Valve amps ALWAYS have an output transformer. Not least because there >>> are no 'P channel ' valves. >> >> I think there were high impedance horn speakers, which wouldn't require >> a transformer. And, of course, high impedance headphones if you don't >> want a loudspeaker. > > Yes some tube TVs had 800 Ohm speakers without transformers. > > Example of a tube output stage without transformer to drive a 800 Ohm speaker: > https://2.bp.blogspot.com/-GaJkZ9klfLw/VOecHjVgPuI/AAAAAAAAA4g/H2qcMWJ3tuA/s1600/Schema.png I'm not familiar with valves EZ80 and 6CA4, I don't understand the drawings. :-? -- Cheers, Carlos. ES🇪🇸, EU🇪🇺;
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| From | John Williamson <johnwilliamson@btinternet.com> |
|---|---|
| Date | 2026-09-30 11:13 +0100 |
| Message-ID | <ni45lsFdufrU1@mid.individual.net> |
| In reply to | #70621 |
On 30/09/2026 10:27, Carlos E.R. wrote: > On 2026-09-29 17:54, Jan Panteltje wrote: >> Yes some tube TVs had 800 Ohm speakers without transformers. >> >> Example of a tube output stage without transformer to drive a 800 Ohm >> speaker: >> >> https://2.bp.blogspot.com/-GaJkZ9klfLw/VOecHjVgPuI/AAAAAAAAA4g/H2qcMWJ3tuA/s1600/Schema.png >> > > I'm not familiar with valves EZ80 and 6CA4, I don't understand the > drawings. :-? > The EZZ80 and BCA4 valves are full wave rectifiers in the power supply. (Equivalent to two diodes in each valve, with a tapped transformer secondary. Back when semiconductors were expensive, I've done similar with a pair of germanium diodes, as it was cheaper than a bridge rectifier.)i The relevant stage for this thread is the output stage, which is two EL504 pentodes being driven in a sort of push-pull configuration by the input triode. The EL504s each have an independent DC supply. The circuit specifies an 800 ohm load, but I first expected to see a more standard 600 ohm load... -- Tciao for Now! John.
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