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An autotransformer is an electrical transformer with only one winding sounds a bit confusing. One winding means one loop of wire in my ears.
I guess it is supposed to be:
An autotransformer is an electrical transformer with only one coil.
Am I right? -- Abdull 12:21, 24 July 2005 (UTC)
This diagram appears to be of a variable autotransformer. Should it not be captioned as such?-- Light current 20:06, 15 January 2006 (UTC)
Duagram shows only step down operation. Is it not true that auto-transformers can also step up? -- Light current 02:32, 16 January 2006 (UTC)
I suppose you could connect it the other way round, but what I was implying is that auto transformers (variable ones anyway) have an over unity ratio as a max (say 120%) then you can tap all the way down from that thro unity ratio toward zero voltage.-- Light current 17:02, 16 January 2006 (UTC)
Thats very kind of you to offer to do that BillC . BTW nice selection of variacs here [1]:-)-- Light current 21:50, 16 January 2006 (UTC)
I think the new diagram looks great. Very clear and obvious. Thanks BillC!-- Light current 23:36, 20 January 2006 (UTC)
what about efficency?
is it suitable for high power applications?
what disadvantages has it over normal transformers? — Preceding
unsigned comment added by
84.222.74.193 (
talk •
contribs)
17:35, 28 May 2006 (UTC)
I placed the merge tags on this article and Buck-boost transformer. A buck-boost transformer is a specific type of autotransformer. Although a buck-boost transformer may use a transformer with multiple windings, they are connected together electrically to form an autotransformer. I think the buck-boost transformer article could be covered with a section in this article. Please post comments below. Thanks. HeirloomGardener 21:53, 18 May 2007 (UTC)
I read that the new UK 'High Speed 1' rail line from London to the Channel Tunnel uses electrification on the 2 x 25 kV autotransformer system, as opposed to the conventional 25 kV system. Could anyone kindly explain what that means, please? Halibut, October 30th 2007. — Preceding unsigned comment added by 193.129.220.13 ( talk • contribs) 19:12, 30 October 2007 (UTC)
Surely there should be some transformer equations so that an autotransformer can be compared to a normal tranformer? Thanks PaulE — Preceding unsigned comment added by 165.228.240.251 ( talk • contribs) 23:21, 1 May 2008 (UTC)
in autotransformer tapping are on high tension or lower tension side?.and why ?.. —Preceding unsigned comment added by 124.30.148.114 ( talk) 07:32, 24 July 2008 (UTC)
What is the difference between the autotransformer and 2 inductors in series ( with no magnetic coupling ) in a step-down application? James. —Preceding unsigned comment added by 80.225.193.212 ( talk) 23:23, 4 September 2009 (UTC)
Just wondering, on this subject, how is an autotransformer different from a normal transformer, but with the grounds of the primary and secondary connected together? Electrically they'd be the same, but not magnetically, so does that make a difference? 188.29.165.174 ( talk) 14:16, 3 October 2013 (UTC)
I've often seen loudspeaker autotransfomers in 100V loudspeaker systems, but every microphone matching transformer I've seen had separate windings, i.e. they were not autotransformers at all. Unless someone has info that such things really do exist, I'll remove the microphone reference in a few days.-- Harumphy ( talk) 10:49, 24 August 2008 (UTC)
Can anyone explain this to me or find a reference?
In UK railway applications, it is common to power the trains at 25kV AC. To increase the distance between Electricity Supply Grid feeder points they can be arranged to supply a 25-0-25 kV supply with the third wire (opposite phase) out of reach of the train's overhead collector pantograph. The OV point of the supply is connected to the rail while one 25kV point is connected to the overhead contact wire. At frequent (about 5km) intervals an autotransformer links the contact wire to rail to third supply conductor. This system reduces induced interference into external equipment and reduces cost. A variant is occasionally seen where the supply conductor is at a different voltage to the contact wire with the autotransformer ratio modified to suit.
A diagram would really help - what purpose does the autotransformer serve here? It might be a good example to keep in the article, if it made sense. -- Wtshymanski ( talk) 16:02, 13 January 2009 (UTC)
I have been trying to improve the articles related to car ignition after finding what I consider to be some real 'howlers' of mistakes ie. using voltage when they should say current.
According to the Transformer types article an Ignition Coil is a Resonant transfomer. So, any opinions?
This may well be so, as anytime you have an inductor and capacitor in parallel you have a 'tank circuit'. But is it significant, in this applicaton. The main point of the cap. is to reduce arcing and point burning, isn't it? Is the cct. actually tuned in any way to get a longer spark. ? See full quote below
My feeling is that this is geting too technical and makes the article less easy to understand.
The articles on the various seperate parts of the overall ignition system are also somewhat inconsistent, repetitive and perhaps again overly detailed.
Sorry for getting 'off-topic' (autotransformers) towards the end here, but the good people commenting seem to know their stuff. If I should address this elsewhere please let me know, i'm fairly new to Wikipedia editing.(first edit 11 September 2009)
Have edited Ignition system, Ignition coil, Contact breaker, Distributor, Spark plug recently so please take a look if you're interested.
-- 220.101.28.25 ( talk) 15:58, 30 October 2009 (UTC)
RE: The links between the UK 400 kV and 275 kV 'Super Grid' networks are normally three phase autotransformers with taps at the common neutral end.
According to the national grids 7 year statement the transformers they normally use between 400kv and 275kv do not have taps. The autotransformers that run at 400kv/132kv and 275kv/132kv do have tap changers however there is no mention of there location in the winding.
CAJ (
talk)
21:54, 18 January 2011 (UTC)
The article shows a photograph of an adjustable autotransformer with a wiping contact, often used as a piece of test equipemnt. This allows it to be adjusted on the fly. How does the wiping contact behave when it moves between adjacent taps? Does it a) break the connect to the first tap then make the connect to the adjacent tap or b) make the connection to the ajacent tap then break from the first tap ?
If case a) then there would be rotor positions where you have now output. From personal experience that doesn't seem to be the case.
If case b) then you have effectively created a shorted single turn ! That's generally considered a bad thing. Why isn't the autotransformer reduced to a smoking heap? :) You must have have something similar happening with the Commutator_(electric) of a DC motor. So this must not be a problem but I don't understand why. — Preceding unsigned comment added by 31.51.250.102 ( talk) 16:04, 16 November 2012 (UTC)
The Autotransformer starter section mentions X-ray detectors ... I just read the referenced page and still can't see any connection.
I *think* the reference to X-ray detectors should just be removed, but this is far enough that I would prefer a second pair of eyes first -- if you agree that the reference is irrelevant, please just delete "and X-ray detectors"
Just plain Bill [ [2]] What is wrong with the links that I put?. Mohmad Abdul sahib 15:13, 24 September 2021 (UTC)
This is the
talk page for discussing improvements to the
Autotransformer article. This is not a forum for general discussion of the article's subject. |
Article policies
|
Find sources: Google ( books · news · scholar · free images · WP refs) · FENS · JSTOR · TWL |
![]() | This article is rated C-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | |||||||||||||||||
|
An autotransformer is an electrical transformer with only one winding sounds a bit confusing. One winding means one loop of wire in my ears.
I guess it is supposed to be:
An autotransformer is an electrical transformer with only one coil.
Am I right? -- Abdull 12:21, 24 July 2005 (UTC)
This diagram appears to be of a variable autotransformer. Should it not be captioned as such?-- Light current 20:06, 15 January 2006 (UTC)
Duagram shows only step down operation. Is it not true that auto-transformers can also step up? -- Light current 02:32, 16 January 2006 (UTC)
I suppose you could connect it the other way round, but what I was implying is that auto transformers (variable ones anyway) have an over unity ratio as a max (say 120%) then you can tap all the way down from that thro unity ratio toward zero voltage.-- Light current 17:02, 16 January 2006 (UTC)
Thats very kind of you to offer to do that BillC . BTW nice selection of variacs here [1]:-)-- Light current 21:50, 16 January 2006 (UTC)
I think the new diagram looks great. Very clear and obvious. Thanks BillC!-- Light current 23:36, 20 January 2006 (UTC)
what about efficency?
is it suitable for high power applications?
what disadvantages has it over normal transformers? — Preceding
unsigned comment added by
84.222.74.193 (
talk •
contribs)
17:35, 28 May 2006 (UTC)
I placed the merge tags on this article and Buck-boost transformer. A buck-boost transformer is a specific type of autotransformer. Although a buck-boost transformer may use a transformer with multiple windings, they are connected together electrically to form an autotransformer. I think the buck-boost transformer article could be covered with a section in this article. Please post comments below. Thanks. HeirloomGardener 21:53, 18 May 2007 (UTC)
I read that the new UK 'High Speed 1' rail line from London to the Channel Tunnel uses electrification on the 2 x 25 kV autotransformer system, as opposed to the conventional 25 kV system. Could anyone kindly explain what that means, please? Halibut, October 30th 2007. — Preceding unsigned comment added by 193.129.220.13 ( talk • contribs) 19:12, 30 October 2007 (UTC)
Surely there should be some transformer equations so that an autotransformer can be compared to a normal tranformer? Thanks PaulE — Preceding unsigned comment added by 165.228.240.251 ( talk • contribs) 23:21, 1 May 2008 (UTC)
in autotransformer tapping are on high tension or lower tension side?.and why ?.. —Preceding unsigned comment added by 124.30.148.114 ( talk) 07:32, 24 July 2008 (UTC)
What is the difference between the autotransformer and 2 inductors in series ( with no magnetic coupling ) in a step-down application? James. —Preceding unsigned comment added by 80.225.193.212 ( talk) 23:23, 4 September 2009 (UTC)
Just wondering, on this subject, how is an autotransformer different from a normal transformer, but with the grounds of the primary and secondary connected together? Electrically they'd be the same, but not magnetically, so does that make a difference? 188.29.165.174 ( talk) 14:16, 3 October 2013 (UTC)
I've often seen loudspeaker autotransfomers in 100V loudspeaker systems, but every microphone matching transformer I've seen had separate windings, i.e. they were not autotransformers at all. Unless someone has info that such things really do exist, I'll remove the microphone reference in a few days.-- Harumphy ( talk) 10:49, 24 August 2008 (UTC)
Can anyone explain this to me or find a reference?
In UK railway applications, it is common to power the trains at 25kV AC. To increase the distance between Electricity Supply Grid feeder points they can be arranged to supply a 25-0-25 kV supply with the third wire (opposite phase) out of reach of the train's overhead collector pantograph. The OV point of the supply is connected to the rail while one 25kV point is connected to the overhead contact wire. At frequent (about 5km) intervals an autotransformer links the contact wire to rail to third supply conductor. This system reduces induced interference into external equipment and reduces cost. A variant is occasionally seen where the supply conductor is at a different voltage to the contact wire with the autotransformer ratio modified to suit.
A diagram would really help - what purpose does the autotransformer serve here? It might be a good example to keep in the article, if it made sense. -- Wtshymanski ( talk) 16:02, 13 January 2009 (UTC)
I have been trying to improve the articles related to car ignition after finding what I consider to be some real 'howlers' of mistakes ie. using voltage when they should say current.
According to the Transformer types article an Ignition Coil is a Resonant transfomer. So, any opinions?
This may well be so, as anytime you have an inductor and capacitor in parallel you have a 'tank circuit'. But is it significant, in this applicaton. The main point of the cap. is to reduce arcing and point burning, isn't it? Is the cct. actually tuned in any way to get a longer spark. ? See full quote below
My feeling is that this is geting too technical and makes the article less easy to understand.
The articles on the various seperate parts of the overall ignition system are also somewhat inconsistent, repetitive and perhaps again overly detailed.
Sorry for getting 'off-topic' (autotransformers) towards the end here, but the good people commenting seem to know their stuff. If I should address this elsewhere please let me know, i'm fairly new to Wikipedia editing.(first edit 11 September 2009)
Have edited Ignition system, Ignition coil, Contact breaker, Distributor, Spark plug recently so please take a look if you're interested.
-- 220.101.28.25 ( talk) 15:58, 30 October 2009 (UTC)
RE: The links between the UK 400 kV and 275 kV 'Super Grid' networks are normally three phase autotransformers with taps at the common neutral end.
According to the national grids 7 year statement the transformers they normally use between 400kv and 275kv do not have taps. The autotransformers that run at 400kv/132kv and 275kv/132kv do have tap changers however there is no mention of there location in the winding.
CAJ (
talk)
21:54, 18 January 2011 (UTC)
The article shows a photograph of an adjustable autotransformer with a wiping contact, often used as a piece of test equipemnt. This allows it to be adjusted on the fly. How does the wiping contact behave when it moves between adjacent taps? Does it a) break the connect to the first tap then make the connect to the adjacent tap or b) make the connection to the ajacent tap then break from the first tap ?
If case a) then there would be rotor positions where you have now output. From personal experience that doesn't seem to be the case.
If case b) then you have effectively created a shorted single turn ! That's generally considered a bad thing. Why isn't the autotransformer reduced to a smoking heap? :) You must have have something similar happening with the Commutator_(electric) of a DC motor. So this must not be a problem but I don't understand why. — Preceding unsigned comment added by 31.51.250.102 ( talk) 16:04, 16 November 2012 (UTC)
The Autotransformer starter section mentions X-ray detectors ... I just read the referenced page and still can't see any connection.
I *think* the reference to X-ray detectors should just be removed, but this is far enough that I would prefer a second pair of eyes first -- if you agree that the reference is irrelevant, please just delete "and X-ray detectors"
Just plain Bill [ [2]] What is wrong with the links that I put?. Mohmad Abdul sahib 15:13, 24 September 2021 (UTC)