I am trying to fault find a fluorescent light on the 12V circuit in our
motor home.

Opinion seems mixed, but there are several postings which claim that these
are actually 240v AC lights with a built in inverter so that they can run
off 12V.

There is certainly a lot of circuitry inside.

Firstly, do camper/caravan/boat 12V fluorescents usually run at 240V with
a built in inverter (or sometimes)?

Secondly if so is there usually clear marking of the 12V and 240V parts?

I don't particularly want to probe a 240V AC circuit with the 50V DC part
of my little multi-meter.

Cheers

Dave R

--
Windows 8.1 on PCSpecialist box

In article ,
David wrote:
I am trying to fault find a fluorescent light on the 12V circuit in our
motor home.

Opinion seems mixed, but there are several postings which claim that
these are actually 240v AC lights with a built in inverter so that they
can run off 12V.

There is certainly a lot of circuitry inside.

Firstly, do camper/caravan/boat 12V fluorescents usually run at 240V
with a built in inverter (or sometimes)?

Secondly if so is there usually clear marking of the 12V and 240V parts?

I don't particularly want to probe a 240V AC circuit with the 50V DC
part of my little multi-meter.

There are probably lots of ways of doing it but the most simple is
basically just an oscillator and transformer to produced approx 240v AC.
Plus a way of producing a higher voltage pulse for starting.

--
*You sound reasonable......time to up my medication

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

In message , David
writes
I am trying to fault find a fluorescent light on the 12V circuit in our
motor home.

Opinion seems mixed, but there are several postings which claim that these
are actually 240v AC lights with a built in inverter so that they can run
off 12V.

There is certainly a lot of circuitry inside.

Firstly, do camper/caravan/boat 12V fluorescents usually run at 240V with
a built in inverter (or sometimes)?

Secondly if so is there usually clear marking of the 12V and 240V parts?

I don't particularly want to probe a 240V AC circuit with the 50V DC part
of my little multi-meter.

Cheers

Dave R

If it is fluorescent then it will have high voltage on it, a tube of
this type will not run at 12V. Could it be a filament tube, a long
light bulb? If so it would likely be 12V, but if there is "a lot of
circuitry" then it is almost certainly an inverter, providing it does
have 12V feeding it I would first suspect the tube, very cheap from any
lighting shop. If the tube is old and the temperature cold then it
would not be unusual for it to have failed.

Have "fun" :-)

--
Bill

In message , "Dave Plowman (News)"
writes
In article ,
David wrote:
I am trying to fault find a fluorescent light on the 12V circuit in our
motor home.

Opinion seems mixed, but there are several postings which claim that
these are actually 240v AC lights with a built in inverter so that they
can run off 12V.

There is certainly a lot of circuitry inside.

Firstly, do camper/caravan/boat 12V fluorescents usually run at 240V
with a built in inverter (or sometimes)?

Secondly if so is there usually clear marking of the 12V and 240V parts?

I don't particularly want to probe a 240V AC circuit with the 50V DC
part of my little multi-meter.

There are probably lots of ways of doing it but the most simple is
basically just an oscillator and transformer to produced approx 240v AC.
Plus a way of producing a higher voltage pulse for starting.

A thought about replacement, with a bit of mechanical ingenuity, an
emergency light unit would provide the parts to make a good replacement.
Probably a darn site cheaper than a new fitting from a motor home shop.


--
Bill

In article ,
David writes:
I am trying to fault find a fluorescent light on the 12V circuit in our
motor home.

What size fluorescent tube are you thinking of?

I would look for LED lighting. In particular, LED retrofits for 12V
electronic transformers will just work without needing anything else.

Opinion seems mixed, but there are several postings which claim that these
are actually 240v AC lights with a built in inverter so that they can run
off 12V.

That seems unlikely to me. It would make the unit unnecessarily
expensive and reduce efficiency.

There is certainly a lot of circuitry inside.

Firstly, do camper/caravan/boat 12V fluorescents usually run at 240V with
a built in inverter (or sometimes)?

No, they ure just electronic ballasts (which use an inverter to drive
the tube directly.) They are usually nowhere near as good as mains
electronic ballasts though.

Secondly if so is there usually clear marking of the 12V and 240V parts?

I don't particularly want to probe a 240V AC circuit with the 50V DC part
of my little multi-meter.

A 12V electronic ballast may well produce in excess of 240V (particularly
cheaper circuit designs) to start the fluorescent tube.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Sat, 27 Dec 2014 13:39:46 +0000, David wrote:

I am trying to fault find a fluorescent light on the 12V circuit in our
motor home.

Opinion seems mixed, but there are several postings which claim that
these are actually 240v AC lights with a built in inverter so that they
can run off 12V.

There is certainly a lot of circuitry inside.

Firstly, do camper/caravan/boat 12V fluorescents usually run at 240V
with a built in inverter (or sometimes)?

Secondly if so is there usually clear marking of the 12V and 240V parts?

I don't particularly want to probe a 240V AC circuit with the 50V DC
part of my little multi-meter.

http://i817.photobucket.com/albums/z...ttleGreyCatUK/
Hymer/20141227_140052.jpg

A bit blurry but hopefully shows enough.




--
Windows 8.1 on PCSpecialist box

In article , Andrew Gabriel
wrote:
In article , David
writes:
I am trying to fault find a fluorescent light on the 12V circuit in our
motor home.

What size fluorescent tube are you thinking of?

I would look for LED lighting. In particular, LED retrofits for 12V
electronic transformers will just work without needing anything else.

Opinion seems mixed, but there are several postings which claim that
these are actually 240v AC lights with a built in inverter so that
they can run off 12V.

That seems unlikely to me. It would make the unit unnecessarily expensive
and reduce efficiency.

Well, they do exist - as emergency light fittings. Usually the battery
supply is 3v or 4.5v, not 12v.

--
From KT24

Using a RISC OS computer running v5.18

In article ,
David wrote:
I am trying to fault find a fluorescent light on the 12V circuit in our
motor home.

Alternatively, throw it away and replace with LED...

Gordon

On 27/12/2014 13:39, David wrote:
I am trying to fault find a fluorescent light on the 12V circuit in our
motor home.

Opinion seems mixed, but there are several postings which claim that these
are actually 240v AC lights with a built in inverter so that they can run
off 12V.

There is certainly a lot of circuitry inside.

Firstly, do camper/caravan/boat 12V fluorescents usually run at 240V with
a built in inverter (or sometimes)?

Secondly if so is there usually clear marking of the 12V and 240V parts?

I don't particularly want to probe a 240V AC circuit with the 50V DC part
of my little multi-meter.


AIUI they're 120V fluorescents with an inverter circuit. Amazon sell
them for about £20 and are not worth repairing. Google "Lumo lights" or
whatever the manufacture's name is on yours.

Another Dave

On 27/12/14 13:39, David wrote:
I am trying to fault find a fluorescent light on the 12V circuit in our
motor home.

Opinion seems mixed, but there are several postings which claim that these
are actually 240v AC lights with a built in inverter so that they can run
off 12V.

There is certainly a lot of circuitry inside.

Firstly, do camper/caravan/boat 12V fluorescents usually run at 240V with
a built in inverter (or sometimes)?

Secondly if so is there usually clear marking of the 12V and 240V parts?

I don't particularly want to probe a 240V AC circuit with the 50V DC part
of my little multi-meter.

Cheers

Dave R

If it is a fluoro., then yes it has an inverter and a current limiter:
basically whizzes up to about 200v ac, then the tube fires, then the
voltage drops to IIRC about 90v peak.

there shouldn't be much on the HV side..half a ferrite transformer and
some sort of ferrite cored choke/current limiter.

the usual suspects here are switching transistors and electrolytics and
bad joints.

if replacing those doesn't work - chuck it. You can buy a new one fr
less than the cost of fixing the old.:-(





--
Everything you read in newspapers is absolutely true, except for the
rare story of which you happen to have first-hand knowledge. €“ Erwin Knoll

On 27/12/14 14:46, Another Dave wrote:
On 27/12/2014 13:39, David wrote:
I am trying to fault find a fluorescent light on the 12V circuit in our
motor home.

Opinion seems mixed, but there are several postings which claim that
these
are actually 240v AC lights with a built in inverter so that they can run
off 12V.

There is certainly a lot of circuitry inside.

Firstly, do camper/caravan/boat 12V fluorescents usually run at 240V with
a built in inverter (or sometimes)?

Secondly if so is there usually clear marking of the 12V and 240V parts?

I don't particularly want to probe a 240V AC circuit with the 50V DC part
of my little multi-meter.


AIUI they're 120V fluorescents with an inverter circuit. Amazon sell
them for about £20 and are not worth repairing. Google "Lumo lights" or
whatever the manufacture's name is on yours.

Another Dave

Looking at the picture, try replacing the big transistor.


--
Everything you read in newspapers is absolutely true, except for the
rare story of which you happen to have first-hand knowledge. €“ Erwin Knoll

On Sat, 27 Dec 2014 14:21:21 +0000, David wrote:

On Sat, 27 Dec 2014 13:39:46 +0000, David wrote:

I am trying to fault find a fluorescent light on the 12V circuit in our
motor home.

Opinion seems mixed, but there are several postings which claim that
these are actually 240v AC lights with a built in inverter so that they
can run off 12V.

There is certainly a lot of circuitry inside.

Firstly, do camper/caravan/boat 12V fluorescents usually run at 240V
with a built in inverter (or sometimes)?

Secondly if so is there usually clear marking of the 12V and 240V
parts?

I don't particularly want to probe a 240V AC circuit with the 50V DC
part of my little multi-meter.

http://i817.photobucket.com/albums/z...ttleGreyCatUK/
Hymer/20141227_140052.jpg

A bit blurry but hopefully shows enough.

http://i817.photobucket.com/albums/z...ttleGreyCatUK/
Hymer/20141227_143106.jpg

shows the whole thing.

One thing doing my head in is that the wiring is blue and brown, (which
should mean 12V negative earth, I think) but to the light the blue seems
+ve and the brown -ve. If you look at the pictures you can see a blue wire
going to the switch and a red wire coming back from the switch to the
circuit board. I've put a multi-meter on it twice and both times confirmed
that blue is +ve and brown -ve. The positive is switched.

The fitting has been in the van and working since we bought the van in
2008 and only recently became progressively more difficult to get started,
and often ran at half brightness at least for a while.

It failed completely a couple of months ago and it proved not to be the
tube as a new tube didn't make any difference.

I assume the circuit board has failed but there are no obvious brown and
smoky bits.

Oh, and just found

http://en.wikipedia.org/wiki/Fluores...s_of_operation

"Fluorescent lamps can run directly from a direct current (DC) supply of
sufficient voltage to strike an arc. The ballast must be resistive, and
would consume about as much power as the lamp. When operated from DC, the
starting switch is often arranged to reverse the polarity of the supply to
the lamp each time it is started; otherwise, the mercury accumulates at
one end of the tube. Fluorescent lamps are (almost) never operated
directly from DC for those reasons. Instead, an inverter converts the DC
into AC and provides the current-limiting function as described below for
electronic ballasts."

So presumably it is likely (but not certain) that the circuit board in the
photo includes an inverter.

Cheers

Dave R

--
Windows 8.1 on PCSpecialist box

In article ,
charles writes:
In article , Andrew Gabriel
wrote:
In article , David
writes:
I am trying to fault find a fluorescent light on the 12V circuit in our
motor home.

What size fluorescent tube are you thinking of?

I would look for LED lighting. In particular, LED retrofits for 12V
electronic transformers will just work without needing anything else.

Opinion seems mixed, but there are several postings which claim that
these are actually 240v AC lights with a built in inverter so that
they can run off 12V.

That seems unlikely to me. It would make the unit unnecessarily expensive
and reduce efficiency.

Well, they do exist - as emergency light fittings. Usually the battery
supply is 3v or 4.5v, not 12v.

Different thing altogether.

The electronic ballast runs from the battery voltage.

Maintained ones (i.e. can also run light off mains) either have a
completely separate ballast for mains operation (most common case in
my experience), or the low voltage charger circuit has enough spare
capacity to run the lamp and charge the battery at the same time.

A common design for the two ballast types uses a 50Hz ballast for
mains running, and a high frequency ballast for battery running.
An advantage with this scheme is both are permenently connected to
the tube and no relay is required. When operating off mains, the
50Hz can't get back through high frequency capacitor ballast into
the high frequency ballast, and when operating on the high frequency
ballast, that can't get back through the 50Hz ballast as the impedance
is far too high at 20kHz+.

Emergency lights are in any case horribly inefficient (at least, the
minature fluorescent tube type with integral battery). They charge
the batteries at high current (has to fully recharge in 14 hours),
but they don't have any smarts inside to stop doing that when the
battery is charged, so it just goes on to waste several watts after
that. They use high temperature batteries so the resulting excess
heat doesn't destroy the batteries.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

In article ,
David writes:
On Sat, 27 Dec 2014 13:39:46 +0000, David wrote:

I am trying to fault find a fluorescent light on the 12V circuit in our
motor home.

Opinion seems mixed, but there are several postings which claim that
these are actually 240v AC lights with a built in inverter so that they
can run off 12V.

There is certainly a lot of circuitry inside.

Firstly, do camper/caravan/boat 12V fluorescents usually run at 240V
with a built in inverter (or sometimes)?

Secondly if so is there usually clear marking of the 12V and 240V parts?

I don't particularly want to probe a 240V AC circuit with the 50V DC
part of my little multi-meter.

http://i817.photobucket.com/albums/z...ttleGreyCatUK/
Hymer/20141227_140052.jpg

A bit blurry but hopefully shows enough.

Most of the circuit is going to be 12V.
The big transformer at the right hand end of the circuit board
is where this is transformed up to a higher voltage for starting
and driving the tube, and you'll find this higher voltage on the
white wires and the tube itself.

These short tubes actually don't run at particularly high voltage
when running at full output, but the starting voltage might be
several hundred volts, depending on how the control gear tries
to start the tube. If the tube dies or is removed, that higher
voltage might remain continuously at the transformer output and
white lamp wires. (It often knackers the transformer winding
insulation if left switched on with a dead or missing tube.)

These short tubes are not as efficient as longer tubes (probably
not much different to a 5W 12V filament bulb), and I would suggest
looking at LED options as I described before.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

I am trying to fault find a fluorescent light on the 12V circuit in our
motor home.

Some of the modern LED lights have quite decent light temperature and
are are a good replacement for fluorescents. I changed all mine in the
motorhome last year and I'm pleased I did. A 5W LED is very nearly as
bright as a 20W fluo.

Bill

On 27/12/2014 13:39, David wrote:
I am trying to fault find a fluorescent light on the 12V circuit in our
motor home.

Opinion seems mixed, but there are several postings which claim that these
are actually 240v AC lights with a built in inverter so that they can run
off 12V.

There is certainly a lot of circuitry inside.

Firstly, do camper/caravan/boat 12V fluorescents usually run at 240V with
a built in inverter (or sometimes)?

Secondly if so is there usually clear marking of the 12V and 240V parts?

I don't particularly want to probe a 240V AC circuit with the 50V DC part
of my little multi-meter.

Cheers

Dave R

Presumably you are talking about striplights? I think they usually have
an inverter of some sort in the mount.

Maybe going off topic, you can buy CFLs with standard bayonet or ES caps
which run straight off 12 volt DC. The electronics is all built into the
cap and they are pretty efficient. (I use these off 12 batteries in a
stables and get much better battery life than I did from a 240 volt
setup with an inverter). You do have to get the polarity right but they
don't "blow" if fitted the wrong way.

"David" wrote in message
...
I am trying to fault find a fluorescent light on the 12V circuit in our
motor home.

Opinion seems mixed, but there are several postings which claim that these
are actually 240v AC lights with a built in inverter so that they can run
off 12V.

There is certainly a lot of circuitry inside.

Firstly, do camper/caravan/boat 12V fluorescents usually run at 240V with
a built in inverter (or sometimes)?

They all have to have an inverter of some sort
because fluoro tubes won't work on 12V.

Secondly if so is there usually clear
marking of the 12V and 240V parts?

No, many of them are designed to have only a 12V input.

I don't particularly want to probe a 240V AC circuit
with the 50V DC part of my little multi-meter.

There isnt any point in probing without knowing
what the function of the bit you are probing is.

"David" wrote in message
...
On Sat, 27 Dec 2014 14:21:21 +0000, David wrote:

On Sat, 27 Dec 2014 13:39:46 +0000, David wrote:

I am trying to fault find a fluorescent light on the 12V circuit in our
motor home.

Opinion seems mixed, but there are several postings which claim that
these are actually 240v AC lights with a built in inverter so that they
can run off 12V.

There is certainly a lot of circuitry inside.

Firstly, do camper/caravan/boat 12V fluorescents usually run at 240V
with a built in inverter (or sometimes)?

Secondly if so is there usually clear marking of the 12V and 240V
parts?

I don't particularly want to probe a 240V AC circuit with the 50V DC
part of my little multi-meter.

http://i817.photobucket.com/albums/z...ttleGreyCatUK/
Hymer/20141227_140052.jpg

A bit blurry but hopefully shows enough.

http://i817.photobucket.com/albums/z...ttleGreyCatUK/
Hymer/20141227_143106.jpg

shows the whole thing.

One thing doing my head in is that the wiring is blue and brown, (which
should mean 12V negative earth, I think) but to the light the blue seems
+ve and the brown -ve. If you look at the pictures you can see a blue wire
going to the switch and a red wire coming back from the switch to the
circuit board. I've put a multi-meter on it twice and both times confirmed
that blue is +ve and brown -ve. The positive is switched.

The fitting has been in the van and working since we bought the van in
2008 and only recently became progressively more difficult to get started,
and often ran at half brightness at least for a while.

It failed completely a couple of months ago and it proved not to be the
tube as a new tube didn't make any difference.

I assume the circuit board has failed but there are no obvious brown and
smoky bits.

Oh, and just found

http://en.wikipedia.org/wiki/Fluores...s_of_operation

"Fluorescent lamps can run directly from a direct current (DC) supply of
sufficient voltage to strike an arc. The ballast must be resistive, and
would consume about as much power as the lamp. When operated from DC, the
starting switch is often arranged to reverse the polarity of the supply to
the lamp each time it is started; otherwise, the mercury accumulates at
one end of the tube. Fluorescent lamps are (almost) never operated
directly from DC for those reasons. Instead, an inverter converts the DC
into AC and provides the current-limiting function as described below for
electronic ballasts."

So presumably it is likely (but not certain) that the circuit board in the
photo includes an inverter.

It is certain because those tubes can't be run on just
12V, the voltage has to be a lot higher than that.

On Saturday, December 27, 2014 1:39:50 PM UTC, David wrote:
I am trying to fault find a fluorescent light on the 12V circuit in our
motor home.

Opinion seems mixed, but there are several postings which claim that these
are actually 240v AC lights with a built in inverter so that they can run
off 12V.

There is certainly a lot of circuitry inside.

Firstly, do camper/caravan/boat 12V fluorescents usually run at 240V with
a built in inverter (or sometimes)?

Secondly if so is there usually clear marking of the 12V and 240V parts?

I don't particularly want to probe a 240V AC circuit with the 50V DC part
of my little multi-meter.

Cheers

Dave R

--
Windows 8.1 on PCSpecialist box

http://donklipstein.com/f-lamp.html it`s in there somewhere

but

LED is going to be better all round, 12V LED tape will live happily up to around 15V and there is a variety of driver modules and star mounted and COB LED packages around to retrofit existing fittings.
You`ll get more light for less battery drain.

Normally these are little blocks that are unserviceable. In answer to your
question yes they use the same tubes as are used on the mains, but instead
of the starter, choke and capacitor used in the mains version to heat the
heaters, and give a higher voltage to strike the tube, the job is done by an
electronic circuit. There seem to be two types, Cheap cold cathode ones and
ones that emulate the heater use.
If the circuit is duff, the cahances are its pretty terminal as mostly its
the inductor that dies, usually gets damp in it and pops its clogs taking
the semiconductor with it. I'm sure new units are available from source on
the web.
If you have checked the tube of course. Normally they are the same fittings
as ordinary ones so find one and test it.
Personally, I often found them annoying in motor caravans with their
radio interference issues and ability to self destruct.
Brian

--
From the Sofa of Brian Gaff Reply address is active
"David" wrote in message
...
I am trying to fault find a fluorescent light on the 12V circuit in our
motor home.

Opinion seems mixed, but there are several postings which claim that these
are actually 240v AC lights with a built in inverter so that they can run
off 12V.

There is certainly a lot of circuitry inside.

Firstly, do camper/caravan/boat 12V fluorescents usually run at 240V with
a built in inverter (or sometimes)?

Secondly if so is there usually clear marking of the 12V and 240V parts?

I don't particularly want to probe a 240V AC circuit with the 50V DC part
of my little multi-meter.

Cheers

Dave R

--
Windows 8.1 on PCSpecialist box

Yes back in theday, I had a unit that had obviously been retro fitted in our
old commer, and when it went on the blink, at first I had no idea of how it
worked.
In the end I sussed that it basically had three main bits. A Unijunction
transistor as a high frequency oscillator f driving two power transistors
with the high voltage generated by a centre tapped transformer, then the
output rectified. The third part appeared to be some kind of current sensor
that operated a regulator for the heaters for a second or so until the tube
started to take current. I rmremember this one as it was one of the few
where the transformer was not to blame, it was one of the two output
transistors that had gone open circuit internally.
I suspect these days its all done in one chip and therefore nobody can fix
them.
Get a decent meter though, as cheapo ones have poor protection.
Brian

--
From the Sofa of Brian Gaff Reply address is active
"Bill" wrote in message
...
In message , "Dave Plowman (News)"
writes
In article ,
David wrote:
I am trying to fault find a fluorescent light on the 12V circuit in our
motor home.

Opinion seems mixed, but there are several postings which claim that
these are actually 240v AC lights with a built in inverter so that they
can run off 12V.

There is certainly a lot of circuitry inside.

Firstly, do camper/caravan/boat 12V fluorescents usually run at 240V
with a built in inverter (or sometimes)?

Secondly if so is there usually clear marking of the 12V and 240V parts?

I don't particularly want to probe a 240V AC circuit with the 50V DC
part of my little multi-meter.

There are probably lots of ways of doing it but the most simple is
basically just an oscillator and transformer to produced approx 240v AC.
Plus a way of producing a higher voltage pulse for starting.

A thought about replacement, with a bit of mechanical ingenuity, an
emergency light unit would provide the parts to make a good replacement.
Probably a darn site cheaper than a new fitting from a motor home shop.


--
Bill

A lot of vehicle wiring uses black and brown as the ground return. Your lights were probably wired that way to avoid confusion with the vans original wiring

On Sat, 27 Dec 2014 13:39:46 +0000, David wrote:

I am trying to fault find a fluorescent light on the 12V circuit in our
motor home.

Opinion seems mixed, but there are several postings which claim that
these are actually 240v AC lights with a built in inverter so that they
can run off 12V.

There is certainly a lot of circuitry inside.

Firstly, do camper/caravan/boat 12V fluorescents usually run at 240V
with a built in inverter (or sometimes)?

Secondly if so is there usually clear marking of the 12V and 240V parts?

I don't particularly want to probe a 240V AC circuit with the 50V DC
part of my little multi-meter.

Thanks for all the input.

LED looks the way to go.

On that subject, has anyone tried just fixing a long strip of LEDs to a
ceiling or under a cupboard to provide dispersed lighting?

Cheers


Dave R


--
Windows 8.1 on PCSpecialist box

David wrote:

has anyone tried just fixing a long strip of LEDs to a
ceiling or under a cupboard to provide dispersed lighting?

My dad uses them glued under the shelves on his pottery stall, outside
my porch, I've used a corner diffuser with the LED strip in it ...

https://www.led-lighthouse.co.uk/led-strip-lights/led-strip-aluminium-profile/corner-aluminium-extrusion-for-led-strip

David wrote:
On that subject, has anyone tried just fixing a long strip of LEDs to a
ceiling or under a cupboard to provide dispersed lighting?

I've done it in drawers and cupboards, always behind a solid shield to
avoid glare. 20mm L-shaped moulding works well, with the LEDs hot-glued
onto the back surface. No diffuser.

--
Mike Barnes
Cheshire, England

"Adam Aglionby" wrote in message
...
On Saturday, December 27, 2014 1:39:50 PM UTC, David wrote:
I am trying to fault find a fluorescent light on the 12V circuit in our
motor home.

Opinion seems mixed, but there are several postings which claim that
these
are actually 240v AC lights with a built in inverter so that they can run
off 12V.

There is certainly a lot of circuitry inside.

Firstly, do camper/caravan/boat 12V fluorescents usually run at 240V with
a built in inverter (or sometimes)?

Secondly if so is there usually clear marking of the 12V and 240V parts?

I don't particularly want to probe a 240V AC circuit with the 50V DC part
of my little multi-meter.

Cheers

Dave R

--
Windows 8.1 on PCSpecialist box

http://donklipstein.com/f-lamp.html it`s in there somewhere

but

LED is going to be better all round, 12V LED tape will live happily up to
around 15V

Mmmm. Gives me an idea for better lighting in the van (as the voltage could
be up to 13.8V)

I was going to fit this for the vans interior LED tape lighting (just had a
few spare metres left over from a job)

http://www.reuk.co.uk/LM2940-12V-1A-...-Regulator.htm



--
Adam

On Wednesday, December 31, 2014 11:58:06 AM UTC, ARW wrote:
"Adam Aglionby" wrote in message
...
On Saturday, December 27, 2014 1:39:50 PM UTC, David wrote:
I am trying to fault find a fluorescent light on the 12V circuit in our
motor home.

Opinion seems mixed, but there are several postings which claim that
these
are actually 240v AC lights with a built in inverter so that they can run
off 12V.

There is certainly a lot of circuitry inside.

Firstly, do camper/caravan/boat 12V fluorescents usually run at 240V with
a built in inverter (or sometimes)?

Secondly if so is there usually clear marking of the 12V and 240V parts?

I don't particularly want to probe a 240V AC circuit with the 50V DC part
of my little multi-meter.

Cheers

Dave R

--
Windows 8.1 on PCSpecialist box

http://donklipstein.com/f-lamp.html it`s in there somewhere

but

LED is going to be better all round, 12V LED tape will live happily up to
around 15V

Mmmm. Gives me an idea for better lighting in the van (as the voltage could
be up to 13.8V)

I was going to fit this for the vans interior LED tape lighting (just had a
few spare metres left over from a job)

http://www.reuk.co.uk/LM2940-12V-1A-...-Regulator.htm



--
Adam

Could be 14.2 on charge, stopped worrying about the over voltage a few years ago, even with cheap tape its lasted for years on couple of vehicles have fitted it to.

Could be 14.2 on charge, stopped worrying about the over voltage a few years ago, even with cheap tape its lasted for years on couple of vehicles have fitted it to.

Could be 15V with a Calcium Lead acid battery.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]