Unlabelled and disconnected mains primary wires
N_Cook
In line , not 2 or more separate primary windings, DC ohms to nearest 0.1
ohm. I'm assuming same gauge wire throughout
Labelled by me as A,B,C,D,E crossplot (message souce maybe equispaced font)
--- A B C D E
A --- 9.2 8.5 12.5 1.5
B 9.2 --- 0.6 3.6 7.6
C 8.5 0.6 --- 4.2 7.6
D 12.5 3.6 4.2 --- 11.1
E 1.5 7.6 7.6 11.1 ---
Would D-E / D-A be 220/240Vac or 230/250V ac?
what would likely be the 110 or 130V interconnctions option ?
Other than checking using a variac , any other tips ?
Gerard Bok
wrote:
Assuming the beast also has a secundary, --possably even marked
with a voltage-- I would apply that voltage (from another
transformer) and measure the voltages on the primary terminals.
--
met vriendelijke groet,
Gerard Bok
Arfa Daily
Look for single wires, indicating winding ends, rather than taps ?
Arfa
N_Cook
news:4c04ef34...@News.Individual.NET...
I hadn't actually thought of that but problem is which crosslink/s? for 110
or 130 V operation. From the deformation set into the leads it was probably
D-E used in the UK so D-A probably 250V. The others can stay disconnected if
need be , as unlikely to ever be used outside the UK
Plain...@yahoo.com
The first step is to rearrange the chart so it makes sense.
The highest resistance is A-D. so A and D are the ends.
A-E is the lowest resistance, so the top line of the chart should now
read
--- A E C B D
A ---1.5 8.5 9.2 12.5
But a better way to look at is is the increments
A-E = winding a = 1.5
E-C = winding b = 7.0
C-B = winding c = 0.7
B-D = winding d = 3.3
NOW let's relabel, and assume that the maximum input voltage is 250
volts (because it's a convenient multiple of 12.5). So the voltage
across each segment (and the taps for each segment) becomes:
A
a = 30
E
b = 140
C
c = 14
B
d = 66
D
Which doesn't make sense for a dual voltage supply UNLESS you assume
multiple gauge wires were used. Which is not unreasonable, factoring
in a desire to save $.02 per device.
Suggestion: A variac (turned down to a very low voltage) would work,
but just about any transformer with an output voltage of 10 -15 volts
should do it. Feed the low voltage AC into the end wirings and
measure the voltage at each tap. Calculate from there.
PlainBill
Gerard Bok
wrote:
>Gerard Bok <bok...@zonnet.nl> wrote in message
>news:4c04ef34...@News.Individual.NET...
>> On Tue, 1 Jun 2010 10:37:06 +0100, "N_Cook" <div...@tcp.co.uk>
>> wrote:
>>
>> >About year 1999, USA make, for export
>> >In line , not 2 or more separate primary windings, DC ohms to nearest 0.1
>> >ohm. I'm assuming same gauge wire throughout
>> >Labelled by me as A,B,C,D,E crossplot (message souce maybe equispaced
>font)
>> >
>> >--- A B C D E
>> >A --- 9.2 8.5 12.5 1.5
>> >B 9.2 --- 0.6 3.6 7.6
>> >C 8.5 0.6 --- 4.2 7.6
>> >D 12.5 3.6 4.2 --- 11.1
>> >E 1.5 7.6 7.6 11.1 ---
>> >
>> >
>> >Would D-E / D-A be 220/240Vac or 230/250V ac?
>> >what would likely be the 110 or 130V interconnctions option ?
>> >Other than checking using a variac , any other tips ?
>>
>> Assuming the beast also has a secundary, --possably even marked
>> with a voltage-- I would apply that voltage (from another
>> transformer) and measure the voltages on the primary terminals.
>I hadn't actually thought of that but problem is which crosslink/s? for 110
>or 130 V operation.
Crosslinks ?
From your original message I read that all primary connections
connect to one continuous winding.
Transformers designed for minimal copper use contain 2 identical
sets of windings. Those get connected in parallel for use on 115
volt and in series for 230 Volt.
As long as there is DC continuity I wouldn't attempt any cross
wiring ;-)
--
Kind regards,
Gerard Bok
Phil Allison
<Plain...@yahoo.com>
>
> But a better way to look at is is the increments
>
> A-E = winding a = 1.5
> E-C = winding b = 7.0
> C-B = winding c = 0.7
> B-D = winding d = 3.3
** OK - let's assume two gauges of wire ARE being used and the 3.3 ohm
tapping B-D is 100V for Japan.
Then by ratio of resistance, the 0.7 ohm tapping C-B is 20 volts making C-D
120 volts for the USA etc.
Similarly, E-C is another 100 volt tapping ( using thinner wire) making E-D
220 volts for Europe.
Again, A-E is another 20 volt tapping making the whole winding 240 volts.
.... Phil
N_Cook
This is what was confusing me , I don't often come across USA transformers ,
they must have plenty of copper to waste and unnecessarily larger
transformers. Only ever seem to see 2 separate primaries in the UK , in the
main, maybe some 10 or 20 V taps in addition.
For this continuous one and generally for this sort of mains transformer.
The"240V" ends cannot be returned to form one 110V connection and a mid
point the other 110V connection for that option, as counter winding sense
for the two "halves" and so no secondary volts.
So part of the winding wasted and the 110V
section of primary perhaps a larger gauge. I suppose measuring inductance
may have helped
PeterD
If it is truely a USA only transformer, it will not have a winding
higher than 120 volts! USA makers were not export oriented, and the
few export units were typically fitted with different transformers,
but the run-of-the-mill domestic production was made with a 120 volt
primary (only). Export models were typically setup for 100/120/240
volts. (Japan, USA & and other countries with an approximate 120 volt
standard, and other countries with an approximate 240 volt standard.)
>they must have plenty of copper to waste and unnecessarily larger
>transformers.
Makers were (and still are) incredibly cheap, and will resort to all
kninds of tricks to save a penny. I don't see many (if any) who will
waste money on copper that will (in their opinion) never be used.
>Only ever seem to see 2 separate primaries in the UK , in the
>main, maybe some 10 or 20 V taps in addition.
>For this continuous one and generally for this sort of mains transformer.
>The"240V" ends cannot be returned to form one 110V connection and a mid
>point the other 110V connection for that option, as counter winding sense
>for the two "halves" and so no secondary volts.
>So part of the winding wasted and the 110V
>section of primary perhaps a larger gauge. I suppose measuring inductance
>may have helped
>
About the best thing would be to measure the primary volts while
powering the secondary with its rated voltage. However, I suspect you
don't know the secondary specifications either, so that is difficult.
I'd probably look at the secondary and give it a known, low voltage
(say 6 v AC) and measure the ratio of the primary voltages. That would
be better than static DC resistance measurements which can easily be
affected by inductance and wire gauge.
PeterD
N_Cook
space. Both methods require a break in winding the primary. The 2 separate
coil system requiring a break and a pair of tails coming off. The continuous
system probably requires a break in gauge of wire and only one tail but 3
dissimilar wires joint at that point - surely not a cheaper option.
Phil Allison
"PeterD"
> If it is truely a USA only transformer, it will not have a winding
> higher than 120 volts! USA makers were not export oriented, and the
> few export units were typically fitted with different transformers,
> but the run-of-the-mill domestic production was made with a 120 volt
> primary (only). Export models were typically setup for 100/120/240
> volts. (Japan, USA & and other countries with an approximate 120 volt
> standard, and other countries with an approximate 240 volt standard.)
** Japan does not have domestic 120 volt AC power.
The standard domestic voltage is 100 volts and may be as low as 90 volts in
some places.
The AC frequency varies too, 50Hz and 60 Hz being used in differing parts of
the country - means that most Japanese made products for domestic use
are designed to accept either frequency.
.... Phil
Phil Allison
"Nutcase Kook is So Full of Shit "
> This is what was confusing me , I don't often come across USA transformers
> ,
> they must have plenty of copper to waste and unnecessarily larger
> transformers. Only ever seem to see 2 separate primaries in the UK , in
> the
> main, maybe some 10 or 20 V taps in addition.
** Wot a load of utter bollocks.
Most audio amps made in the UK between the mid 1960s and late 1990s had
multi-voltage, single winding AC transformers.
Check any old schem from Marshall, Vox or Sugden etc, et alia.
http://www.audiomisc.co.uk/JES/A21series2/A21series2.html
http://www.schematicheaven.com/marshallamps/jcm800_lead_mstvol_50w_2204.pdf
http://www.schematicheaven.com/voxamps/ac301960.pdf
http://www.schematicheaven.com/voxamps/ac151960.pdf
.... Phil
hr(bob) hofmann@att.net
Do you know the approximate secondary voltage? If yes. apply that
voltage to the secondary using a variac or some other transformer.
Then measure the various primary voltages. I have done that many
times when all else fails and I didn't want to take a chance on frying
the transformer. Should work just as well east of the big pond as on
the west side.
Cydrome Leader
you never mentioned what you're even talking about, or what it's from.
Assuming it's something like an "international" linear power supply, there would be
windings for 100, 120 220 and 240 volts based off a combination of terminals. US made
transformers for domestic only use would generally max out at 3 or 4 terminals for
120/240 use.
here's a diagram of how these international transformers work:
http://www.slpower.com/Upload/Technical/20070404102642455201154_41-32512F_ML_Series.pdf
PeterD
wrote:
>
Geeze Phil, read... Japan is 100, USA and other countries with
approximately 120 volts, and still other countries with 240 volts.
Completely clear to everyone else...
OK, for you:
>>(Japan at 100 volts, USA & and other countries with an approximate 120 volt
Phil Allison
>
> "Phil Allison"
>>
>> Export models were typically setup for 100/120/240 volts (Japan, USA
>> & and other countries with an approximate 120 volt standard, and other
>> countries with an approximate 240 volt standard.)
>>
>
>>** Japan does not have domestic 120 volt AC power.
>>
>>The standard domestic voltage is 100 volts and may be as low as 90 volts
>>in
>>some places.
>>
>>The AC frequency varies too, 50Hz and 60 Hz being used in differing parts
>>of
>>the country - means that most Japanese made products for domestic use
>>are designed to accept either frequency.
>>
>
** What I read was misleading and * needed correction*.
It is a very common myth that Japan has 120 volt AC, 60Hz power ( like the
USA) when it does NOT !!
Your post repeated that myth.
Cos of eBay, second hand Japanese local market electronics is now being sold
to folk in all parts of the world to use - most of whom mistakenly think
that it can be used on 120 volts AC or with a 240 to 120 volts step down
tranny.
.... Phil
N_Cook
news:hu6geg$qkj$1...@reader1.panix.com...
That transformer type is the 2 separate primaries, not the subject of this
thread.
Does anyone have the generic name for these wasteful construction made in or
for USA , for export kit ? the ones with a (electrically) continuous single
primary winding
Grant
Autotransformer.
What results from driving the secondary with a low voltage?
Grant.
--
http://bugs.id.au/
N_Cook
news:tkne06ltbli2a5aij...@4ax.com...
My understanding of the term autotransformer is primary and secondary
electrically continuous, ie no electrical isolation
Ron
Multitap?
N_Cook
news:z5KdnW0VXPQ_7prR...@bt.com..
> Multitap?
You can have multitaps on dual primary ones for variants on the theme of
110/240V, so not an exclusive term
Grant
Phil Allison
"Nutcase Kook is So Full of Shit "
> Does anyone have the generic name for these wasteful construction made in
> or
> for USA , for export kit ? the ones with a (electrically) continuous
> single
> primary winding
>
** Wot a load of utter bollocks
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Most audio amps made in the ** UK ** between the mid 1960s and late 1990s
had
multi-voltage, single winding AC transformers.
Check any old schem from Marshall, Vox or Sugden etc, et alia.
http://www.audiomisc.co.uk/JES/A21series2/A21series2.html
http://www.schematicheaven.com/marshallamps/jcm800_lead_mstvol_50w_2204.pdf
http://www.schematicheaven.com/voxamps/ac301960.pdf
http://www.schematicheaven.com/voxamps/ac151960.pdf
Nutcase Kook is Soooooo... Full of Shit
.... Phil
Phil Allison
Nutcase Kook is Sooooo Full of Shit
>> Multitap?
>
>
> You can have multitaps on dual primary ones for variants on the theme of
> 110/240V, so not an exclusive term
** Nutcase Kook is Sooooooooooooo Full of Shit !!!
.... Phil
David Nebenzahl
> On Thu, 3 Jun 2010 09:12:07 +0100, "N_Cook" <div...@tcp.co.uk> wrote:
>
>> Grant <o...@grrr.id.au> wrote in message
>> news:tkne06ltbli2a5aij...@4ax.com...
>>
>>> What results from driving the secondary with a low voltage?
>>
>> My understanding of the term autotransformer is primary and
>> secondary electrically continuous, ie no electrical isolation
>>
> You're not looking for answers, are you?
He rarely is. Just sitting at the bar bending the ears of whatever poor
saps sitting nearby are willing to listen to his ramblings.
--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.
- Comment from an article on Antiwar.com (http://antiwar.com)
Cydrome Leader
You're right- they must have just cheapened their transformers. Condor
stuff used to have the 5 terminal primary windings. If you can find a
manual for an older generation "international linear power supply" how
those windings are setup is diagrammed.
They're not a single winding though, and not nearly as wasteful as 50Hz
mains frequency when it comes to excessive use of materials and size.