A neighbour called me to tell me she had put new batteries in her CO2 /
smoke alarm and they were getting hot!
I went to look and as you can guess they had been fitted wrong - but I was
really surprised by the amount of heat they generated. (3 xAA)

Has the manufacturer never heard of a series diode?

Of course provided the design could cope with a 1.2 volt voltage drop, one
could fit a bridge and then it would not matter which way around it was.
Brian
Brian

--
From the Sofa of Brian Gaff Reply address is active
"DerbyBorn" wrote in message
2.236...
A neighbour called me to tell me she had put new batteries in her CO2 /
smoke alarm and they were getting hot!
I went to look and as you can guess they had been fitted wrong - but I was
really surprised by the amount of heat they generated. (3 xAA)

Brian Gaff wrote:
Has the manufacturer never heard of a series diode?

Some stuff has one connected so that it's normally reverse biased, and
shorts out a battery connected the wrong way. The fuse is optional, but
costs more.

Of course provided the design could cope with a 1.2 volt voltage drop, one
could fit a bridge and then it would not matter which way around it was.

That would mean that you would either need an extra cell, or would have
a much reduced useful life from the ones you put in.


--
Tciao for Now!

John.

"DerbyBorn" wrote in message
2.236...
A neighbour called me to tell me she had put new batteries in her CO2 /
smoke alarm and they were getting hot!
I went to look and as you can guess they had been fitted wrong - but I was
really surprised by the amount of heat they generated. (3 xAA)

I wouldn't be surprised, not after putting the two AA batteries into a Lidl
torch and finding it didn't work.
By the time I got back to the shop (about 5 minutes) it was melting the
plastic bits.
Next time I will remember to take the batteries out.

On 24/09/2012 18:08, Brian Gaff wrote:
Has the manufacturer never heard of a series diode?

Of course provided the design could cope with a 1.2 volt voltage drop, one
could fit a bridge and then it would not matter which way around it was.
Brian
Brian


Please bottom post, especially if you have a signature with "--" in a
preceding line.

It is possible to use a modest MOSFET, which can combine a diode and a
low resistance switch, to reduce any voltage drop to near zero.

The old fashioned method was simply to have a battery housing which
fails to make contact when batteries are put in backwards.

Fredxx wrote:
On 24/09/2012 18:08, Brian Gaff wrote:
Has the manufacturer never heard of a series diode?

Of course provided the design could cope with a 1.2 volt voltage
drop, one could fit a bridge and then it would not matter which way
around it was. Brian
Brian


Please bottom post, especially if you have a signature with "--" in a
preceding line.

If you want to get revenge then just post a link to a
picture..........................

--
Adam

On Mon, 24 Sep 2012 19:43:48 +0100, Fredxx wrote:

On 24/09/2012 18:08, Brian Gaff wrote:
Has the manufacturer never heard of a series diode?

Of course provided the design could cope with a 1.2 volt voltage drop,
one
could fit a bridge and then it would not matter which way around it was.
Brian
Brian


Please bottom post, especially if you have a signature with "--" in a
preceding line.

Are you new here? Brian top posts for a very good reason.

--
Rod

Fredxx wrote:
On 24/09/2012 18:08, Brian Gaff wrote:
Has the manufacturer never heard of a series diode?

Of course provided the design could cope with a 1.2 volt voltage drop,
one
could fit a bridge and then it would not matter which way around it was.
Brian
Brian


Please bottom post, especially if you have a signature with "--" in a
preceding line.

Those who know about Brian's blindness excuse him from the usual rigours
on top posting, as he uses a screen reader.

--
Tciao for Now!

John.

On 24/09/2012 19:59, John Williamson wrote:
Fredxx wrote:
On 24/09/2012 18:08, Brian Gaff wrote:
Has the manufacturer never heard of a series diode?

Of course provided the design could cope with a 1.2 volt voltage
drop, one
could fit a bridge and then it would not matter which way around it was.
Brian
Brian


Please bottom post, especially if you have a signature with "--" in a
preceding line.

Those who know about Brian's blindness excuse him from the usual rigours
on top posting, as he uses a screen reader.


For one I wasn't aware of Brian blindness. But it's a shame that
whatever news client he uses makes it difficult to bottom post.

It has it's consequences, especially as Brian uses "--" in his signature
thereby removing any of the OP's original post when replying with most
news clients.

There are also those die-hards who refuse to reply to anyone who top posts!!

Fredxx wrote:
On 24/09/2012 19:59, John Williamson wrote:
Fredxx wrote:
On 24/09/2012 18:08, Brian Gaff wrote:
Has the manufacturer never heard of a series diode?

Of course provided the design could cope with a 1.2 volt voltage
drop, one
could fit a bridge and then it would not matter which way
around it was. Brian
Brian


Please bottom post, especially if you have a signature with "--"
in a preceding line.

Those who know about Brian's blindness excuse him from the usual
rigours on top posting, as he uses a screen reader.


For one I wasn't aware of Brian blindness. But it's a shame that
whatever news client he uses makes it difficult to bottom post.

It has it's consequences, especially as Brian uses "--" in his
signature thereby removing any of the OP's original post when
replying with most news clients.

There are also those die-hards who refuse to reply to anyone who top
posts!!

He has been buggering around with his sig in the last few days.

--
Adam

On Mon, 24 Sep 2012 20:46:39 +0100, Fredxx wrote:

On 24/09/2012 19:59, John Williamson wrote:
Fredxx wrote:
On 24/09/2012 18:08, Brian Gaff wrote:
Has the manufacturer never heard of a series diode?

Of course provided the design could cope with a 1.2 volt voltage
drop, one
could fit a bridge and then it would not matter which way around it
was.
Brian
Brian


Please bottom post, especially if you have a signature with "--" in a
preceding line.

Those who know about Brian's blindness excuse him from the usual rigours
on top posting, as he uses a screen reader.


For one I wasn't aware of Brian blindness. But it's a shame that
whatever news client he uses makes it difficult to bottom post.

It has it's consequences, especially as Brian uses "--" in his signature
thereby removing any of the OP's original post when replying with most
news clients.

There are also those die-hards who refuse to reply to anyone who top
posts!!

No - it's because he uses "-- ".

Die-hards can do what they like.

--
Rod

On Mon, 24 Sep 2012 18:51:50 +0100, "dennis@home"
wrote:



"DerbyBorn" wrote in message
. 92.236...
A neighbour called me to tell me she had put new batteries in her CO2 /
smoke alarm and they were getting hot!
I went to look and as you can guess they had been fitted wrong - but I was
really surprised by the amount of heat they generated. (3 xAA)

I wouldn't be surprised, not after putting the two AA batteries into a Lidl
torch and finding it didn't work.
By the time I got back to the shop (about 5 minutes) it was melting the
plastic bits.
Next time I will remember to take the batteries out.

On your way out of Lidl you might have noticed a clear plastic bin for
customers to put their depleted batteries in for WEEE compliance or
whatever.
Am I alone in thinking there is a potential fire risk if or more good
lithium or alkaline batteries got in there, perhaps a couple of 9V
types. Optionally add a little wire wool and tissue paper and stir
slowly.

--
Graham.
%Profound_observation%

dennis@home wrote:
"DerbyBorn" wrote in message
2.236...
A neighbour called me to tell me she had put new batteries in her
CO2 / smoke alarm and they were getting hot!
I went to look and as you can guess they had been fitted wrong -
but I was really surprised by the amount of heat they generated. (3
xAA)

I wouldn't be surprised, not after putting the two AA batteries into
a Lidl torch and finding it didn't work.
By the time I got back to the shop (about 5 minutes) it was melting
the plastic bits.
Next time I will remember to take the batteries out.

Makes note - dennis is unable to correctly fit a pair of AA batteries into a
torch.

--
Adam

On Mon, 24 Sep 2012 22:21:16 +0100, ARW wrote:

dennis@home wrote:
"DerbyBorn" wrote in message
2.236...
A neighbour called me to tell me she had put new batteries in her CO2
/ smoke alarm and they were getting hot! I went to look and as you
can guess they had been fitted wrong - but I was really surprised by
the amount of heat they generated. (3 xAA)

I wouldn't be surprised, not after putting the two AA batteries into a
Lidl torch and finding it didn't work. By the time I got back to the
shop (about 5 minutes) it was melting the plastic bits.
Next time I will remember to take the batteries out.

Makes note - dennis is unable to correctly fit a pair of AA batteries
into a torch.

It was probably a torch designed for a couple of D cells.

polygonum wrote:

On Mon, 24 Sep 2012 19:43:48 +0100, Fredxx wrote:

On 24/09/2012 18:08, Brian Gaff wrote:
Has the manufacturer never heard of a series diode?

Of course provided the design could cope with a 1.2 volt voltage drop,
one
could fit a bridge and then it would not matter which way around it was.
Brian
Brian


Please bottom post, especially if you have a signature with "--" in a
preceding line.

Are you new here? Brian top posts for a very good reason.


To be fair, Brian's sig does mention the fact - but it took me a while to
realise because I never read sigs either...

--
Tim Watts

On Mon, 24 Sep 2012 19:43:48 +0100, Fredxx wrote:

Please bottom post, especially if you have a signature with "--" in a
preceding line.

Brian is allowed as he's like Pew.

On Tue, 25 Sep 2012 01:28:30 +0000 (UTC), Jules Richardson
wrote:

On Mon, 24 Sep 2012 22:21:16 +0100, ARW wrote:

dennis@home wrote:
"DerbyBorn" wrote in message
2.236...
A neighbour called me to tell me she had put new batteries in her CO2
/ smoke alarm and they were getting hot! I went to look and as you
can guess they had been fitted wrong - but I was really surprised by
the amount of heat they generated. (3 xAA)

I wouldn't be surprised, not after putting the two AA batteries into a
Lidl torch and finding it didn't work. By the time I got back to the
shop (about 5 minutes) it was melting the plastic bits.
Next time I will remember to take the batteries out.

Makes note - dennis is unable to correctly fit a pair of AA batteries
into a torch.

It was probably a torch designed for a couple of D cells.

You too?

--
Graham.
%Profound_observation%

In article , Grimly
Curmudgeon writes
On Mon, 24 Sep 2012 19:43:48 +0100, Fredxx wrote:

Please bottom post, especially if you have a signature with "--" in a
preceding line.

Brian is allowed as he's like Pew.

Wooden :-?
--
fred
it's a ba-na-na . . . .

Tim Watts wrote:
polygonum wrote:

On Mon, 24 Sep 2012 19:43:48 +0100, Fredxx
wrote:

On 24/09/2012 18:08, Brian Gaff wrote:
Has the manufacturer never heard of a series diode?

Of course provided the design could cope with a 1.2 volt
voltage drop, one
could fit a bridge and then it would not matter which way
around it was. Brian
Brian


Please bottom post, especially if you have a signature with "--"
in a preceding line.

Are you new here? Brian top posts for a very good reason.


To be fair, Brian's sig does mention the fact - but it took me a
while to realise because I never read sigs either...

Does that include not reading his new sig that does not mention the fact?

--
Adam

ARW wrote:

Tim Watts wrote:
polygonum wrote:

On Mon, 24 Sep 2012 19:43:48 +0100, Fredxx
wrote:

On 24/09/2012 18:08, Brian Gaff wrote:
Has the manufacturer never heard of a series diode?

Of course provided the design could cope with a 1.2 volt
voltage drop, one
could fit a bridge and then it would not matter which way
around it was. Brian
Brian


Please bottom post, especially if you have a signature with "--"
in a preceding line.

Are you new here? Brian top posts for a very good reason.


To be fair, Brian's sig does mention the fact - but it took me a
while to realise because I never read sigs either...

Does that include not reading his new sig that does not mention the fact?


Dunno - I never read sigs ;-
--
Tim Watts

On Tue, 25 Sep 2012 12:33:35 +0100, Grimly Curmudgeon wrote:

On Mon, 24 Sep 2012 19:43:48 +0100, Fredxx wrote:

Please bottom post, especially if you have a signature with "--" in a
preceding line.

Brian is allowed as he's like Pew.

Did you just get hit by a laser mid-sentence?

En el artículo , Fredxx
escribió:

Please bottom post, especially if you have a signature with "--" in a
preceding line.

Brian has a valid reason for top-posting. Leave him alone.

--
(\_/)
(='.'=)
(")_(")

In article ,
Tim Watts wrote:
Dunno - I never read sigs ;-

You'd miss the best bit of my posts - by far.

--
*Pride is what we have. Vanity is what others have.

Dave Plowman London SW
To e-mail, change noise into sound.