Voltage and polarity of pre war Rovers
JHB
Does anyone off hand know the voltage and polarity of the pre war
Rover electrical systems?
Thanks
John Baker
Dave Plowman (News)
<23275d64-d247-4fa6...@a1g2000hsb.googlegroups.com>,
JHB <Baker...@gmail.com> wrote:
> Hi:
> Does anyone off hand know the voltage and polarity of the pre war
> Rover electrical systems?
I *think* Rovers stayed with negative earth - even when others changed to
positive. The only pre-war one I had dealing with was 12 volts. But surely
this would be easy to ascertain by looking at a bulb etc if the battery is
missing?
> Thanks
> John Baker
--
*Stable Relationships Are For Horses.
Dave Plowman da...@davenoise.co.uk London SW
To e-mail, change noise into sound.
Mike G
"JHB" <Baker...@gmail.com> wrote in message
news:23275d64-d247-4fa6...@a1g2000hsb.googlegroups.com...
> Hi:
>
> Does anyone off hand know the voltage and polarity of the pre
> war
> Rover electrical systems?
AFAIR, most if not all prewar cars had 12v negative earths.
VW beetles were the only exception I know of that had a 6v
system.
Mike.
R N Robinson
"Mike G" <met...@largefoot.com> wrote in message
news:6iktguF...@mid.individual.net...
Don't know many pre-war VW's. Quite a few small cars used 6v pre-war, but I
would expect something the size and quality of a Rover (even the 10hp) to
have been 12v and negative earth. In the absence of anything obvious to the
contrary it should be reasonable to proceed on that assumption. Unless we
are talking about an air-cooled flat twin 8hp of course.
Ron Robinson
Malcolm
"R N Robinson" <ron...@frumiousbandersnatch.freeserve.co.uk> wrote in
message news:ga3thu$q11$1...@aioe.org...
about the 8hp I'm afraid though I know someone who has one if we are
desperate to know.
It is most certainly not true to say that most pre war cars are 12volt. All
the Fords and I think Vauxhalls are 6 volt as well as the Morris 8.
Malcolm
Mike G
"Malcolm" <malcolm$$1234$$@btinternet.com> wrote in message
news:laqdnUtOz6PaEVjV...@bt.com...
Nope.
The Ford Y type I once owned, along with a Morris Series 1 and 2
and an E type were certainly 12v.
Mike.
Dave Plowman (News)
Mike G <met...@largefoot.com> wrote:
> The Ford Y type I once owned, along with a Morris Series 1 and 2
> and an E type were certainly 12v.
Interesting - the sit up and beg post war Fords were 6 volt.
--
*Thank you. We're all refreshed and challenged by your unique point of view
Dave Plowman (News)
Mike G <met...@largefoot.com> wrote:
> "JHB" <Baker...@gmail.com> wrote in message
> news:23275d64-d247-4fa6...@a1g2000hsb.googlegroups.com...
> > Hi:
> >
> > Does anyone off hand know the voltage and polarity of the pre
> > war
> > Rover electrical systems?
> AFAIR, most if not all prewar cars had 12v negative earths.
I reckon positive earth was a post war thingie. Said to extend plug and
points life.
> VW beetles were the only exception I know of that had a 6v
> system.
Pre-war Beetles?
--
*Dancing is a perpendicular expression of a horizontal desire *
Mike G
"Dave Plowman (News)" <da...@davenoise.co.uk> wrote in message
news:4fdbd9a...@davenoise.co.uk...
> In article <6iktguF...@mid.individual.net>,
> Mike G <met...@largefoot.com> wrote:
>
>> "JHB" <Baker...@gmail.com> wrote in message
>> news:23275d64-d247-4fa6...@a1g2000hsb.googlegroups.com...
>> > Hi:
>> >
>> > Does anyone off hand know the voltage and polarity of the
>> > pre
>> > war
>> > Rover electrical systems?
>
>> AFAIR, most if not all prewar cars had 12v negative earths.
>
> I reckon positive earth was a post war thingie. Said to extend
> plug and
> points life.
>
>> VW beetles were the only exception I know of that had a 6v
>> system.
>
> Pre-war Beetles?
Yes.
Pre war Beetles had a 6 volt system, which was retained in the
ones produced post war.
Mike.
Jim Warren
I have just looked up Rover in my copy of "Modern Motor Cars" dated 1937.
Both the Rover 10 and the Rover 12 are shown as 12V Positive Earth.
Jim
Roger
from "Mike G" <met...@largefoot.com> contains these words:
> > Pre-war Beetles?
> Yes.
> Pre war Beetles had a 6 volt system, which was retained in the
> ones produced post war.
I thought that pre-war Beetles was a bit optimistic but a quick google
brought up the information that there were a few pre production
prototype Beetles made before war broke out. Production was actually
scheduled to begin in September 1939. I doubt very much whether any of
of the few prototypes would have made it to the UK before September 1939
though.
Memory fades but my faded memory tells me that 6 volt systems were
common back in 1962 when I bought my first car which, paradoxically, was
a 1939 Rover 12 with a 12 volt system.
--
Roger Chapman
Kevin Poole
12v, insulated return:
Rover 10 1928-9
Standard 9 1929
Singer Senior 1929
Beardmore Taxicab 1929
Riley 9 1929
Citroen Swift
6v, insulated return:
Singer Junior 1929
6v, +ve earth
Ford 1929
6v, -ve earth:
Triumph 7 1929
Austin 7 1929
Citroen 1929
Essex 1929
Buick Light 6 1929
Trojan 1929 (fused between battery and earth)
and, while Mike G has stated categorically that Morris 8s were 12v, I'll
state, equally categorically, that they were 6v. Believe who you like.
Source for the detailed stuff above: "Motor Repair and Overhauling", Vol
II, George T Clarke, Newnes.
Also 6v, -ve earth:
MG Series M (source: Blower)
ICBA to look up any later cars at the moment.
--
Kevin Poole
****Use current date to reply (e.g. sep...@mainbeam.co.uk)****
Malcolm
> Nope.
> The Ford Y type I once owned, along with a Morris Series 1 and 2 and an E
> type were certainly 12v.
> Mike.
>
Then they must have been converted to 12 volt. My books show the Morris 8 up
to the Series E as 6 volt negative earth. People selling electrical spareas
for the Ford Y seem to think its 6 volt.
Malcolm
Kevin Poole
Jim Warren wrote:
> JHB wrote:
>> Hi:
>>
>> Does anyone off hand know the voltage and polarity of the pre war
>> Rover electrical systems?
>>
>
> I have just looked up Rover in my copy of "Modern Motor Cars" dated 1937.
>
> Both the Rover 10 and the Rover 12 are shown as 12V Positive Earth.
>
And by 1940 (possibly sooner) so were the 14, 16, and 20hp Rovers
Richard Green
Pre-war Rovers used negative earth until part-way through the 1936 model
year, when they changed to positive earth. All models used conventional
earth return through the chassis.
Regards,
Richard Green
Tuesday 09/09/2008, 14:21
Dave Plowman (News)
Richard Green <ric...@ragreen.plus.com> wrote:
> Pre-war Rovers used negative earth until part-way through the 1936 model
> year, when they changed to positive earth. All models used conventional
> earth return through the chassis.
It's interesting that at least some of their models reverted to negative
earth long before electronics made this necessary. And of course Rolls
Royce stayed with negative earth.
--
*If at first you don't succeed, try management *
Richard Green
I've never been clear whether car electronics are made with negative
earth because they have to be, or purely through convention, most cars
having negative earth when they were introduced. Certainly some of the
early radio/cassette players and accessory rev counters were switchable.
Regards,
Richard
Tuesday 09/09/2008, 16:18
Chris Bolus
I think it's largely convention - transistors can be made in either
polarity, though in the early days npn types were cheaper and there was
a greater range of them. No other component requires a connection to the
casing (most transistors don't either, but it was/is common with power
transistors for cooling) so there is no technical reason for either
earth polarity to be dominant.
--
Regards, Chris (Please take out my car to reply by plain text email)
------1967 Riley Elf------1978 Mini 1000------1971 Mini Clubman------
--1972 Mini Clubman estate--1979 Ford Capri--1984 VW Type 25 camper--
Dave Plowman (News)
Richard Green <ric...@ragreen.plus.com> wrote:
> I've never been clear whether car electronics are made with negative
> earth because they have to be, or purely through convention, most cars
> having negative earth when they were introduced. Certainly some of the
> early radio/cassette players and accessory rev counters were switchable.
The first transistors were geranium and PNP so basically positive ground.
And very expensive. Silicon ones are NPN and negative ground - and they're
also very much cheaper to manufacture. Or were when they arrived.
Cars were all negative earth until some time in the mid '30s (according to
some here - I thought it was after WW2) and then some makes changed to
positive earth - but not in all countries. The change back did sort of
coincide with the arrival of cheaper electronics based round silicon
technology.
You can, of course, make any electronic device float - ie not connected to
the car ground, except at the battery. But this makes things much more
expensive than necessary - as well as introducing problems.
--
*Remember: First you pillage, then you burn.
Chris Bolus
<da...@davenoise.co.uk> wrote:
>In article <AuKdnej_OIdgDlvV...@posted.plusnet>,
> Richard Green <ric...@ragreen.plus.com> wrote:
>> I've never been clear whether car electronics are made with negative
>> earth because they have to be, or purely through convention, most cars
>> having negative earth when they were introduced. Certainly some of the
>> early radio/cassette players and accessory rev counters were switchable.
>
>The first transistors were geranium and PNP so basically positive ground.
Not all. When I was doing a lot of electronics in the 70s, one of the
most common transistors was the AC128 - an NPN germanium.
(FWIW they're now very sought-after by guitar fx builders!)
>And very expensive. Silicon ones are NPN and negative ground - and they're
>also very much cheaper to manufacture. Or were when they arrived.
>
But of course, apart from where heatsinking is required, there is no
need to connect any part of the transistor to ground. So an electronic
circuit board can be made with any polarity provided insulating mounts
are used.
So by and large it's convention.
Dave Plowman (News)
Chris Bolus <chr...@RILEYELFb0lus.com> wrote:
> On Tue, 09 Sep 2008 18:49:43 +0100, "Dave Plowman (News)"
> <da...@davenoise.co.uk> wrote:
> >In article <AuKdnej_OIdgDlvV...@posted.plusnet>,
> > Richard Green <ric...@ragreen.plus.com> wrote:
> >> I've never been clear whether car electronics are made with negative
> >> earth because they have to be, or purely through convention, most
> >> cars having negative earth when they were introduced. Certainly some
> >> of the early radio/cassette players and accessory rev counters were
> >> switchable.
> >
> >The first transistors were geranium and PNP so basically positive
> >ground.
> Not all. When I was doing a lot of electronics in the 70s, one of the
> most common transistors was the AC128 - an NPN germanium.
Indeed. I was generalising. But PNP transistors were the norm with
geranium in the same way as NPN is the norm with silicon. If you look at a
catalogue from the '60s you'll see that NPN were rare and expensive.
> (FWIW they're
> now very sought-after by guitar fx builders!)
That says much about their performance. ;-)
> >And very expensive. Silicon ones are NPN and negative ground - and
> >they're also very much cheaper to manufacture. Or were when they
> >arrived.
> >
> But of course, apart from where heatsinking is required, there is no
> need to connect any part of the transistor to ground. So an electronic
> circuit board can be made with any polarity provided insulating mounts
> are used.
> So by and large it's convention.
Cars use the chassis as one leg of the supply. So anything which had
peripherals - like injection etc - would have to use fully insulated
sensors with wired returns.
--
*I don't suffer from insanity; I enjoy every minute of it.
JHB
earth.
I appreciate the response. I am in USA and have wanted a pre war Rover
10 or 12 for years. Having seen one advertised (in the UK) I was
interested in some of the details I had not explored before before I
took the plunge abnd contacted the seller
Thanks a lot
Malcolm
>> In article <8uKdnV2w29AJ5VvV...@posted.plusnet>,
>> Richard Green <ric...@ragreen.plus.com> wrote:
>>> Pre-war Rovers used negative earth until part-way through the 1936 model
>>> year, when they changed to positive earth. All models used conventional
>>> earth return through the chassis.
>>
>> It's interesting that at least some of their models reverted to negative
>> earth long before electronics made this necessary. And of course Rolls
>> Royce stayed with negative earth.
> Hello Dave,
> I've never been clear whether car electronics are made with negative earth
> because they have to be, or purely through convention, most cars having
> negative earth when they were introduced. Certainly some of the early
> radio/cassette players and accessory rev counters were switchable.
> Regards,
> Richard
> Tuesday 09/09/2008, 16:18>>
Looking for something completeyly different I came across this in
"Automobile Electrical Maintenance" published in 1938.
-----------------------
Positive Earthing
Hitherto it has been the custom in single-pole systems to earth the negative
pole of the battery to the chassis frame. More recently, however, it has
become the practice to earth the positive terminal since there are certain
advantages in the latter method. In the first place the h.t. distributor arm
of the ignition unit becomes negative to the distributor contacts so that it
does not burn away as before. Secondly, the central electrode of the
sparking plug is now negative to the metal shell of the plug, so that any
corrosion, or burning away, is now confined to the metal shell and not to
the central electrode. Another advantage lies in the relatively lower
temperature of the central electrode, whereby a lower "high tension" voltage
can be employed to produce the spark.
-----------------
I understand some of the reasoning but not the bit about lower voltage.
Malcolm
Dave Plowman (News)
Malcolm <malcolm$$1234$$@btinternet.com> wrote:
> Looking for something completeyly different I came across this in
> "Automobile Electrical Maintenance" published in 1938.
> -----------------------
> Positive Earthing
> Hitherto it has been the custom in single-pole systems to earth the
> negative pole of the battery to the chassis frame. More recently,
> however, it has become the practice to earth the positive terminal
> since there are certain advantages in the latter method. In the first
> place the h.t. distributor arm of the ignition unit becomes negative to
> the distributor contacts so that it does not burn away as before.
> Secondly, the central electrode of the sparking plug is now negative to
> the metal shell of the plug, so that any corrosion, or burning away, is
> now confined to the metal shell and not to the central electrode.
> Another advantage lies in the relatively lower temperature of the
> central electrode, whereby a lower "high tension" voltage can be
> employed to produce the spark.
> ----------------- I understand some of the reasoning but not the bit
> about lower voltage.
I suppose it means if there's less erosion you don't need as high a
voltage to cope with an increased gap - or that resistance increases with
temperature. But a bit tenuous.
I've a feeling that the above article misses out that positive earth
increases body corrosion for the reasons given.
--
*The man who fell into an upholstery machine is fully recovered*
Geoff Mackenzie
"Dave Plowman (News)" <da...@davenoise.co.uk> wrote in message
news:4fdd9a9...@davenoise.co.uk...
ISTR that the issue of body corrosion due to polarity was not generally
recognised in the thirties; it was only some years after the war that it
was confirmed as an issue and the general move back to negative earth
occurred.
Of course, BMC took a novel approach by fitting sacrificial anodes. They
called them doorhandles.
GMacK
Peter Chadbund
according to wiring diagrams which I have.
"JHB" <Baker...@gmail.com> wrote in message
news:23275d64-d247-4fa6...@a1g2000hsb.googlegroups.com...
Grimly Curmudgeon
drugs began to take hold. I remember Roger <ro...@nospam.zetnet.co.uk>
saying something like:
>I thought that pre-war Beetles was a bit optimistic but a quick google
>brought up the information that there were a few pre production
>prototype Beetles made before war broke out. Production was actually
>scheduled to begin in September 1939.
Istr reading that the very first production models were presented to
selected 'winners' of a lottery (fixed, I've no doubt) in various local
ceremonies held througout the Reich, as an incentive for the workers to
keep putting money into the VW pot. Of course, such events were
thoroughly covered by Joe Goebbels at the time and the cars were taken
back as soon as the cameras left, to be 'presented' to the next lucky
winner, on the promise that as soon as production really got going
they'd get a new car - real soon now.
There was some sort of workers' fund set up to produce the Beetle and if
the war hadn't happened the production VWs would have been filling the
streets, driven by grinning family men as they drove their flaxen-headed
Hans and Heidis to Youth Camp.
--
Dave
SE6a
Grimly Curmudgeon
<gm...@chapterfive.org.uk> saying something like:
>Of course, BMC took a novel approach by fitting sacrificial anodes. They
>called them doorhandles.
Or subframes.
--
Dave
SE6a