I have a motor which runs on 16v AC. It has a double wound field coil,
and is more correctly a universal motor, as it will also run on DC, but
that is irrelevant, I think.

There are four terminals. Power runs from a transformer to A, which is
one side of the field coil.

From there, current runs through the field coil to B, and from B to C,
which is one brush. The other brush is D, from where current runs back
to the transformer.

To reverse the motor, wires are swapped, so that power coming out of the
field coil (B) goes to brush D (not C), and back to the transformer via
C, not D.

What I cannot work out is how to use a switch, or switches, to achieve
remote reversing of the motor. Ideally, I would have two push buttons,
one for each direction, but any switch would suffice. The switch(es)
need to be able to supply the power, and swap the way the brush caps are
connected.

Any thoughts on the switches I need, and how to wire them would be
appreciated. The motor only needs to run for about twenty seconds, in
either direction.
--
Graeme

In article ,
Graeme wrote:
I have a motor which runs on 16v AC. It has a double wound field coil,
and is more correctly a universal motor, as it will also run on DC, but
that is irrelevant, I think.

There are four terminals. Power runs from a transformer to A, which is
one side of the field coil.

From there, current runs through the field coil to B, and from B to C,
which is one brush. The other brush is D, from where current runs back
to the transformer.

To reverse the motor, wires are swapped, so that power coming out of the
field coil (B) goes to brush D (not C), and back to the transformer via
C, not D.

What I cannot work out is how to use a switch, or switches, to achieve
remote reversing of the motor. Ideally, I would have two push buttons,
one for each direction, but any switch would suffice. The switch(es)
need to be able to supply the power, and swap the way the brush caps are
connected.

You need what's known as a double pole changeover (DPDT). Perhaps the most
common type you'd find is an intermediate switch - a third switch fitted
to a household two way switched lighting circuit, between the start and
finish switches.

Any thoughts on the switches I need, and how to wire them would be
appreciated. The motor only needs to run for about twenty seconds, in
either direction.

You can buy double pole changeover switches from the likes of Maplin.

http://www.maplin.co.uk/Search.aspx?menuno=12886

Toggle types are also available.

For push button control the easiest way would be with relays.

Note and intermediate switch has only four terminals as two of the six
which a DPDT switch has are linked internally.

--
*We have enough youth, how about a fountain of Smart?

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

Graeme wrote:
I have a motor which runs on 16v AC. It has a double wound field
coil, and is more correctly a universal motor, as it will also run on
DC, but that is irrelevant, I think.

There are four terminals. Power runs from a transformer to A, which
is one side of the field coil.

From there, current runs through the field coil to B, and from B to C,
which is one brush. The other brush is D, from where current runs
back to the transformer.

To reverse the motor, wires are swapped, so that power coming out of
the field coil (B) goes to brush D (not C), and back to the
transformer via C, not D.

What I cannot work out is how to use a switch, or switches, to achieve
remote reversing of the motor. Ideally, I would have two push
buttons, one for each direction, but any switch would suffice. The
switch(es) need to be able to supply the power, and swap the way the
brush caps are connected.

Any thoughts on the switches I need, and how to wire them would be
appreciated. The motor only needs to run for about twenty seconds, in
either direction.

You need what's called a DPDT switch (Double Pole, Double Throw). You can
also get them with a centre-off position. If you Google for DPDT Switch I'm
sure you'll find what you need.
--
Dave Baker

Graeme wrote:

I have a motor which runs on 16v AC. It has a double wound field coil,
and is more correctly a universal motor, as it will also run on DC, but
that is irrelevant, I think.

There are four terminals. Power runs from a transformer to A, which is
one side of the field coil.

From there, current runs through the field coil to B, and from B to C,
which is one brush. The other brush is D, from where current runs back
to the transformer.

To reverse the motor, wires are swapped, so that power coming out of the
field coil (B) goes to brush D (not C), and back to the transformer via
C, not D.

What I cannot work out is how to use a switch, or switches, to achieve
remote reversing of the motor. Ideally, I would have two push buttons,
one for each direction, but any switch would suffice. The switch(es)
need to be able to supply the power, and swap the way the brush caps are
connected.

Any thoughts on the switches I need, and how to wire them would be
appreciated. The motor only needs to run for about twenty seconds, in
either direction.


You need a DPDT switch (Double Pole, Double Throw) to allow (C) (D) to
be connected to either (B) or the transformer...

(fixed width font, ASCII art)



Transformer(1) --------------------- (A)

----------------- (B)
|
|
|
+-----o
| \o-------- (C)
Transformer(2) --- | -+- o
| |
| |
| +--o
| \o-------- (D)
+-----o


^ DPDT Switch



The DPDT switch could be either a physical switch, or implemented using
the contacts on a DPDT relay (then arrange push buttons to provide power
to energise the relay / motor).

You could use DPST push buttons, and two relays to achieve exactly what
you want....

Use one pole of each push button, in parallel, to energise the coil of
relay (1), the SPST contacts of which provide the switched power from
Transformer(1) to the field coil (A). This allows either push button to
provide the power to the motor.

Use the second pole of ONE of the push buttons, to entergise the coil of
relay (2), which uses the DPDT contact arrangement shown above.

Using this, either button energises the motor, so the motor will spin,
but one button will invert the wiring of (C)/(D) thus reversing the motor.

In message , "Dave Plowman (News)"
writes
In article ,
Graeme wrote:

You can buy double pole changeover switches from the likes of Maplin.

http://www.maplin.co.uk/Search.aspx?menuno=12886

Thanks to both Daves. Yes, I think the Maplin IP65 centre off rocker
switch is absolutely perfect.
--
Graeme

In message , Mike Dodd
writes

Transformer(1) --------------------- (A)

----------------- (B)
|
|
|
+-----o
| \o-------- (C)
Transformer(2) --- | -+- o
| |
| |
| +--o
| \o-------- (D)
+-----o


^ DPDT Switch

Thanks Mike - I can see that diagram perfectly, and I have a standard
DPDT toggle switch, but just cannot get the wiring right. Looking at
the bottom of the switch, there are six terminals :


-------
| 1 2 |
| |
| 3 4 |
| |
| 5 6 |
-------

I'm having a real brain dead day. Transformer (2) above goes to
terminal 3 or 4 on the switch? 3 or 4 is also hard wired to (B)?

(C) and (D) are connected to terminals 2 and 6?

Thank you!
--
Graeme

Graeme explained :
I have a motor which runs on 16v AC. It has a double wound field coil, and
is more correctly a universal motor, as it will also run on DC, but that is
irrelevant, I think.

There are four terminals. Power runs from a transformer to A, which is one
side of the field coil.

From there, current runs through the field coil to B, and from B to C, which
is one brush. The other brush is D, from where current runs back to the
transformer.

To reverse the motor, wires are swapped, so that power coming out of the
field coil (B) goes to brush D (not C), and back to the transformer via C,
not D.

What I cannot work out is how to use a switch, or switches, to achieve remote
reversing of the motor. Ideally, I would have two push buttons, one for each
direction, but any switch would suffice. The switch(es) need to be able to
supply the power, and swap the way the brush caps are connected.

Any thoughts on the switches I need, and how to wire them would be
appreciated. The motor only needs to run for about twenty seconds, in either
direction.

I can't think of a readily available push button that would do this as
a single switch solution, but what is known as an intermediate switch
would set the motor up to run forward or reverse, with a separate push
button to act as the run button. Intermediate switches are used in
domestic and commercial lighting circuits, to add extra switches to a
two way lighting circuit.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

Graeme wrote:
In message , Mike Dodd
writes

Transformer(1) --------------------- (A)

----------------- (B)
|
|
|
+-----o
| \o-------- (C)
Transformer(2) --- | -+- o
| |
| |
| +--o
| \o-------- (D)
+-----o


^ DPDT Switch

Thanks Mike - I can see that diagram perfectly, and I have a standard
DPDT toggle switch, but just cannot get the wiring right. Looking at
the bottom of the switch, there are six terminals :


-------
| 1 2 |
| |
| 3 4 |
| |
| 5 6 |
-------

I'm having a real brain dead day. Transformer (2) above goes to
terminal 3 or 4 on the switch? 3 or 4 is also hard wired to (B)?

(C) and (D) are connected to terminals 2 and 6?

Thank you!


Switch terminals marked, in accordance with your diagram:-

(at least for the most common switch arrangements that I've come across)


Transformer(1) --------------------- (A)

----------------- (B)
|
|
| 1
+-----o 3
| \o-------- (C)
Transformer(2) --- | -+- o
| | 5
| |
| | 2
| +--o 4
| \o-------- (D)
+-----o
6

Graeme wrote:

Thanks Mike - I can see that diagram perfectly, and I have a standard
DPDT toggle switch, but just cannot get the wiring right. Looking at
the bottom of the switch, there are six terminals :


-------
| 1 2 |
| |
| 3 4 |
| |
| 5 6 |
-------

I'm having a real brain dead day. Transformer (2) above goes to
terminal 3 or 4 on the switch? 3 or 4 is also hard wired to (B)?

(C) and (D) are connected to terminals 2 and 6?

Thank you!


On your switch, connect 1 to 6 and connect 2 to 5. You now have
effectively a 4 switch which will swap over one (either) pair of
motor wires.

Beware with this arrangement of the possiblity of reversing polarity
while motor is still spinning.


NT

In message , Mike Dodd
writes

Switch terminals marked, in accordance with your diagram:-

Transformer(1) --------------------- (A)

----------------- (B)
|
|
| 1
+-----o 3
| \o-------- (C)
Transformer(2) --- | -+- o
| | 5
| |
| | 2
| +--o 4
| \o-------- (D)
+-----o
6

Perfect. Absolutely perfect. Thank you. I cannot tell you how
delighted I am. I have found a DPDT slide switch, centre off, which
will suffice until I buy a rocker switch. This is to control the motor
within an old (pre war) tinplate toy crane. The motor powers the
slewing function, and the design of the crane permits slewing for about
150 degrees in each direction, so the facility to reverse the motor is
absolutely essential.

The switch is usually hard wired to the crane, so finding an original
replacement switch for a crane without one is not going to be easy;
hence the need to find something that would suffice. Thanks again.
--
Graeme

In article ,
Graeme wrote:
Thanks Mike - I can see that diagram perfectly, and I have a standard
DPDT toggle switch, but just cannot get the wiring right. Looking at
the bottom of the switch, there are six terminals :


-------
| 1 2 |
| |
| 3 4 |
| |
| 5 6 |
-------

I'm having a real brain dead day. Transformer (2) above goes to
terminal 3 or 4 on the switch? 3 or 4 is also hard wired to (B)?

1,3,5 are one pole, 2,4,6 t'other.

link 1 and 6. 2 and 5. Input to 3&4, output from 5&6.

--
*Time is fun when you're having flies... Kermit

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

On Sun, 28 Dec 2008 10:31:40 +0000, Graeme
wrote:


I have a motor which runs on 16v AC. It has a double wound field coil,
and is more correctly a universal motor, as it will also run on DC, but
that is irrelevant, I think.

There are four terminals. Power runs from a transformer to A, which is
one side of the field coil.

From there, current runs through the field coil to B, and from B to C,
which is one brush. The other brush is D, from where current runs back
to the transformer.

To reverse the motor, wires are swapped, so that power coming out of the
field coil (B) goes to brush D (not C), and back to the transformer via
C, not D.

What I cannot work out is how to use a switch, or switches, to achieve
remote reversing of the motor. Ideally, I would have two push buttons,
one for each direction, but any switch would suffice. The switch(es)
need to be able to supply the power, and swap the way the brush caps are
connected.

Any thoughts on the switches I need, and how to wire them would be
appreciated. The motor only needs to run for about twenty seconds, in
either direction.

changeover relay?

Graeme wrote:
In message , Mike Dodd
writes


Perfect. Absolutely perfect. Thank you. I cannot tell you how
delighted I am.

It's a pleasure - a rare experience on Usenet.

Interesting to hear the application, too, nice to hear that you're
injecting a bit of life back into some proper toys

"Mike Dodd" wrote in message
...
Graeme wrote:
In message , Mike Dodd
writes


Perfect. Absolutely perfect. Thank you. I cannot tell you how
delighted I am.

It's a pleasure - a rare experience on Usenet.

Makes a nice change from the bickering eh
--
Dave Baker

In message , Mike Dodd
writes
Graeme wrote:
In message , Mike Dodd
writes

Perfect. Absolutely perfect. Thank you. I cannot tell you how
delighted I am.

It's a pleasure - a rare experience on Usenet.

Interesting to hear the application, too, nice to hear that you're
injecting a bit of life back into some proper toys

Grin My interest is old toy trains, particularly pre war tinplate,
and the crane I have been working on is American Flyer, from very early
post war days. Repairing the older equipment is usually fairly
straightforward - it is finding it in the first place that is difficult.
--
Graeme