power choke with 3 leads...

[Ralph Mowery]

A friend found a choke in his junk box and asked about it. I found one
similar to it in mine. They are iron core chokes similar to the old
tube TV power supply section would have in it. They are probably over 50
years old and most likely came from an old TV set.

The question is why do they have 3 wires instead of 2 wires that the
other chokes I have seen have ?

I know they are not the output transformer of a push pull audio stage
that may have had the speaker wires cut off, but that is what they
resemble.

 

[Mike Coon]

In article <MPG.3b71d1d0f37a31bc98991c@news.eternal-september.org>,
rmowery42@charter.net says...

A friend found a choke in his junk box and asked about it. I found one
similar to it in mine. They are iron core chokes similar to the old
tube TV power supply section would have in it. They are probably over 50
years old and most likely came from an old TV set.

The question is why do they have 3 wires instead of 2 wires that the
other chokes I have seen have ?

I know they are not the output transformer of a push pull audio stage
that may have had the speaker wires cut off, but that is what they
resemble.

What are the resistances?

 

[Peter W.]

Common Mode chokes will have three (or more) wires - they are designed to filter rF and reduce EMI (for the most part, not always).

Peter Wieck
Melrose Park, PA

 

[Ralph Mowery]

In article <971fb451-8912-4640-bad7-d50c0c2e2a5an@googlegroups.com>,
peterwieck33@gmail.com says...

Common Mode chokes will have three (or more) wires - they are designed to filter rF and reduce EMI (for the most part, not always).

Peter Wieck
Melrose Park, PA

Yes, I am aware of the common chokes for RF. However this is a large
iron core choke similar in size and make up of a 2 wire choke used in
the DC supply of a radio or old tube TV set.

 

[Ralph Mowery]

In article <MPG.3b7227b6e9cda2ba113@news.plus.net>,
gravity@mjcoon.plus.com says...

A friend found a choke in his junk box and asked about it. I found one
similar to it in mine. They are iron core chokes similar to the old
tube TV power supply section would have in it. They are probably over 50
years old and most likely came from an old TV set.

The question is why do they have 3 wires instead of 2 wires that the
other chokes I have seen have ?

I know they are not the output transformer of a push pull audio stage
that may have had the speaker wires cut off, but that is what they
resemble.

What are the resistances?

There seems to be one winding with a tap on it.
From one end to the other is about 280 ohms. From one end to another
wire is 272 ohms and the other is 8 ohms.

Again this is an iron core choke ? that is large enough to be used as a
normal 2 wire power supply choke in a tube type TV set of the 1950\'s .

 

[Ralph Mowery]

In article <MPG.3b7227b6e9cda2ba113@news.plus.net>,
gravity@mjcoon.plus.com says...

A friend found a choke in his junk box and asked about it. I found one
similar to it in mine. They are iron core chokes similar to the old
tube TV power supply section would have in it. They are probably over 50
years old and most likely came from an old TV set.

The question is why do they have 3 wires instead of 2 wires that the
other chokes I have seen have ?

I know they are not the output transformer of a push pull audio stage
that may have had the speaker wires cut off, but that is what they
resemble.

What are the resistances?

There seems to be one winding with a tap on it.
From one end to the other is about 280 ohms. From one end to another
wire is 272 ohms and the other is 8 ohms.

Again this is an iron core choke ? that is large enough to be used as a
normal 2 wire power supply choke in a tube type TV set of the 1950\'s .

 

[Rob]

Ralph Mowery <rmowery42@charter.net> wrote:

In article <MPG.3b7227b6e9cda2ba113@news.plus.net>,
gravity@mjcoon.plus.com says...

A friend found a choke in his junk box and asked about it. I found one
similar to it in mine. They are iron core chokes similar to the old
tube TV power supply section would have in it. They are probably over 50
years old and most likely came from an old TV set.

The question is why do they have 3 wires instead of 2 wires that the
other chokes I have seen have ?

I know they are not the output transformer of a push pull audio stage
that may have had the speaker wires cut off, but that is what they
resemble.

What are the resistances?



There seems to be one winding with a tap on it.
From one end to the other is about 280 ohms. From one end to another
wire is 272 ohms and the other is 8 ohms.

Again this is an iron core choke ? that is large enough to be used as a
normal 2 wire power supply choke in a tube type TV set of the 1950\'s .

This sounds more like an transformer, with one contact common between
primary and secundary, than a choke.

Does it have an airgap in the core?

 

[Ralph Mowery]

In article <slrnsggob2.qlh.nomail@xs9.xs4all.nl>, nomail@example.com
says...

This sounds more like an transformer, with one contact common between
primary and secundary, than a choke.

Does it have an airgap in the core?

There is no airgap that I can see. It could be an autotransformer.
While I am familiar with simple tube circuits, the old TV sets are
before my time so to speak. I would still like to see how it would be
used in an application.

 

[Ralph Mowery]

In article <slrnsggob2.qlh.nomail@xs9.xs4all.nl>, nomail@example.com
says...

This sounds more like an transformer, with one contact common between
primary and secundary, than a choke.

Does it have an airgap in the core?

There is no airgap that I can see. It could be an autotransformer.
While I am familiar with simple tube circuits, the old TV sets are
before my time so to speak. I would still like to see how it would be
used in an application.

 

[Phil Allison]

Ralph Mowery wrote:
=================

This sounds more like an transformer, with one contact common between
primary and secundary, than a choke.

Does it have an airgap in the core?


There is no airgap that I can see. It could be an autotransformer.
While I am familiar with simple tube circuits, the old TV sets are
before my time so to speak. I would still like to see how it would be
used in an application.

** Could be a speaker transformer.
The TV set would have a live chassis.



...... Phil

 

[Ralph Mowery]

In article <9ebae237-0c57-42bd-af5a-1dd85fec6bf3n@googlegroups.com>,
pallison49@gmail.com says...

There is no airgap that I can see. It could be an autotransformer.
While I am familiar with simple tube circuits, the old TV sets are
before my time so to speak. I would still like to see how it would be
used in an application.

** Could be a speaker transformer.
The TV set would have a live chassis.

I am not familiar with that kind of speaker transformer. Are you saying
it is used in a method coming off the audio tube plate in a maner
similar to an autotransformer is used in power line circuits ?

It may make sense as there is a low resistance in series with a high
resistance winding.

 

[Ralph Mowery]

In article <9ebae237-0c57-42bd-af5a-1dd85fec6bf3n@googlegroups.com>,
pallison49@gmail.com says...

There is no airgap that I can see. It could be an autotransformer.
While I am familiar with simple tube circuits, the old TV sets are
before my time so to speak. I would still like to see how it would be
used in an application.

** Could be a speaker transformer.
The TV set would have a live chassis.

I am not familiar with that kind of speaker transformer. Are you saying
it is used in a method coming off the audio tube plate in a maner
similar to an autotransformer is used in power line circuits ?

It may make sense as there is a low resistance in series with a high
resistance winding.

 

[Phil Allison]

Ralph Mowery wrote:
=================

There is no airgap that I can see. It could be an autotransformer.
While I am familiar with simple tube circuits, the old TV sets are
before my time so to speak. I would still like to see how it would be
used in an application.

** Could be a speaker transformer.
The TV set would have a live chassis.

I am not familiar with that kind of speaker transformer. Are you saying
it is used in a method coming off the audio tube plate in a maner
similar to an autotransformer is used in power line circuits ?

** Yep.

It may make sense as there is a low resistance in series with a high
resistance winding.

** I imagined there is one continuous winding with a tap at 8/280.
That is a voltage ratio of 35:1 or an impedance ratio of 1225:1

About what you expect for a single ended, pentode output stage.

There would still need to be an air gap cos of unbalanced DC current in the primary.
Just means all the Es and Is are lined up and not interleaved.

Quick and very easy transformer to make.


...... Phil

 

[legg]

On Mon, 2 Aug 2021 10:57:20 -0400, Ralph Mowery
<rmowery42@charter.net> wrote:

A friend found a choke in his junk box and asked about it. I found one
similar to it in mine. They are iron core chokes similar to the old
tube TV power supply section would have in it. They are probably over 50
years old and most likely came from an old TV set.

The question is why do they have 3 wires instead of 2 wires that the
other chokes I have seen have ?

I know they are not the output transformer of a push pull audio stage
that may have had the speaker wires cut off, but that is what they
resemble.

Tapped series chokes were once used for voltage selection under very
dedicated load conditions ~ fan speed control or heater settings.

Perhaps it\'s a tube heater (12 - 6V) range.

RL

 

[legg]

On Mon, 2 Aug 2021 10:57:20 -0400, Ralph Mowery
<rmowery42@charter.net> wrote:

A friend found a choke in his junk box and asked about it. I found one
similar to it in mine. They are iron core chokes similar to the old
tube TV power supply section would have in it. They are probably over 50
years old and most likely came from an old TV set.

The question is why do they have 3 wires instead of 2 wires that the
other chokes I have seen have ?

I know they are not the output transformer of a push pull audio stage
that may have had the speaker wires cut off, but that is what they
resemble.

Tapped series chokes were once used for voltage selection under very
dedicated load conditions ~ fan speed control or heater settings.

Perhaps it\'s a tube heater (12 - 6V) range.

RL

 

[Jeff Liebermann]

On Mon, 2 Aug 2021 10:57:20 -0400, Ralph Mowery
<rmowery42@charter.net> wrote:

A friend found a choke in his junk box and asked about it. I found one
similar to it in mine. They are iron core chokes similar to the old
tube TV power supply section would have in it. They are probably over 50
years old and most likely came from an old TV set.

The question is why do they have 3 wires instead of 2 wires that the
other chokes I have seen have ?

I know they are not the output transformer of a push pull audio stage
that may have had the speaker wires cut off, but that is what they
resemble.

Autotransformer. If it were a single center tap winding, applying
120VAC between the tap and one common end, would produce 240VAC
between the common end and the other end. I suspect it\'s really old
as such an arrangement might be considered an electrocution hazard.
<https://en.wikipedia.org/wiki/Autotransformer>
<https://www.google.com/search?q=autotransformer&tbm=isch>

--
Jeff Liebermann jeffl@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Ralph Mowery]

In article <u9llggp8n498qt8pk1iu8u195tvrqdtlq3@4ax.com>,
jeffl@cruzio.com says...

Autotransformer. If it were a single center tap winding, applying
120VAC between the tap and one common end, would produce 240VAC
between the common end and the other end. I suspect it\'s really old
as such an arrangement might be considered an electrocution hazard.
https://en.wikipedia.org/wiki/Autotransformer
https://www.google.com/search?q=autotransformer&tbm=isch

It is really old, more than 40 years old that I know of and much older
than that as it came out of a black and white TV as best as I can
remember. The total resistance is about 280 ohms with a tap of about 8
ohms from one end.

Guess it could be for a couple of filiments of some of the old tubes it
was mentioned that it could be the plate transformer of the audio stage
to speaker . As the set it came out of was probably as old or older
than I am I have not seen a tube circuit that used a transformer that
way . I am just not up on the very old tube circuits.

If it was a standard transformer that put out 6.3 volts it would be good
for about 3 to 5 amps judging by its size. All the E cores are facing
one direction and the I segments are all at one end instead of
alternating like most transformers.

 

[Ralph Mowery]

In article <u9llggp8n498qt8pk1iu8u195tvrqdtlq3@4ax.com>,
jeffl@cruzio.com says...

Autotransformer. If it were a single center tap winding, applying
120VAC between the tap and one common end, would produce 240VAC
between the common end and the other end. I suspect it\'s really old
as such an arrangement might be considered an electrocution hazard.
https://en.wikipedia.org/wiki/Autotransformer
https://www.google.com/search?q=autotransformer&tbm=isch

It is really old, more than 40 years old that I know of and much older
than that as it came out of a black and white TV as best as I can
remember. The total resistance is about 280 ohms with a tap of about 8
ohms from one end.

Guess it could be for a couple of filiments of some of the old tubes it
was mentioned that it could be the plate transformer of the audio stage
to speaker . As the set it came out of was probably as old or older
than I am I have not seen a tube circuit that used a transformer that
way . I am just not up on the very old tube circuits.

If it was a standard transformer that put out 6.3 volts it would be good
for about 3 to 5 amps judging by its size. All the E cores are facing
one direction and the I segments are all at one end instead of
alternating like most transformers.

 

[Liz Tuddenham]

Ralph Mowery <rmowery42@charter.net> wrote:

...All the E cores are facing
one direction and the I segments are all at one end instead of
alternating like most transformers.

That shows it is designed to handle DC or a very asymmetrical waveform.
My guess would be a frame output autotransformer for driving the field
coils around the tube neck.


--
~ Liz Tuddenham ~
(Remove the \".invalid\"s and add \".co.uk\" to reply)
www.poppyrecords.co.uk

 

[Phil Allison]

legg wrote more crap:
===================

Perhaps it\'s a tube heater (12 - 6V) range.

** Not with a source impedance of around 16 ohms.