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  #1   Report Post  
Paul Probus
 
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Default Treadmill motor controller schematic at dropbox retired

I have printed off the pdf version of the treadmill motor controller
schematic at the dropbox retired files. As I was looking it over, I
saw that there are some components that aren't labeled as to what
values they should be. For example, R2 and R4 are not labeled what
their resistance values should be. In addition, and I will admit that
I am a complete novice to electronics, I have no idea what L1 is
supposed to represent and there are no values for its size, so I
cannot even make a guess. I am hoping that those who developed the
schematic are still here.

While I do have interest in using the controller as-is (if I can get
the values needed) I am also interested in what it would take to
modify the controller for use to control universal motors because I
have need for controlling the speed of a large router, since the
TDA1085C controller IC was designed primarily for universal motors
according to Motorola's literature that I printed off.

TIA,
Paul
  #2   Report Post  
Richard J Kinch
 
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Default Treadmill motor controller schematic at dropbox retired

Paul Probus writes:

I have printed off the pdf version of the treadmill motor controller
schematic at the dropbox retired files.


URL?
  #3   Report Post  
Wayne Cook
 
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Default Treadmill motor controller schematic at dropbox retired

On 5 Mar 2004 11:57:16 -0800, (Paul Probus)
wrote:

I have printed off the pdf version of the treadmill motor controller
schematic at the dropbox retired files. As I was looking it over, I
saw that there are some components that aren't labeled as to what
values they should be. For example, R2 and R4 are not labeled what
their resistance values should be. In addition, and I will admit that
I am a complete novice to electronics, I have no idea what L1 is
supposed to represent and there are no values for its size, so I
cannot even make a guess. I am hoping that those who developed the
schematic are still here.

I'm still here but I'm pretty far from a expert compared to most of
this group. I just reverse engineered the schematic from the board.

As for the values of R2 and R4 they should be on the schematic. At
least they're on the copy that I've got in front of me right now
(you're lucky that I just cleaned up my office and happened to find my
copy a couple of days ago). According to this one R2 is 4K and R4 is
4.74K.

L1 is a torrodial choke and I've not got any clue what it's rated
at. It is one of several components on the board that would be
difficult to source but could probably be worked around by somebody
with more electronics engineering experience than I have.

Keep in mind that there's a resister not shown on the schematic and
not obvious when looking at the board. It's in the form of one of the
traces on the board itself. It snakes around to make for a low value
high capacity resistor in the power portion of the circuit.



While I do have interest in using the controller as-is (if I can get
the values needed) I am also interested in what it would take to
modify the controller for use to control universal motors because I
have need for controlling the speed of a large router, since the
TDA1085C controller IC was designed primarily for universal motors
according to Motorola's literature that I printed off.


The big problem you'll have is that this controller needs a
tachometer on the motor to function properly. That might be hard to
add to a router.

The fact is that I'm not to one who came up with any of the
modifications to the board. I just had the time to make up the
schematic by tracing the board (wish I had that kind of free time now
days). I then posted it and let others do the figuring on how to
modify it.

Wayne Cook
Shamrock, TX
  #4   Report Post  
Don Foreman
 
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Default Treadmill motor controller schematic at dropbox retired

On 5 Mar 2004 11:57:16 -0800, (Paul Probus)
wrote:

I have printed off the pdf version of the treadmill motor controller
schematic at the dropbox retired files. As I was looking it over, I
saw that there are some components that aren't labeled as to what
values they should be. For example, R2 and R4 are not labeled what
their resistance values should be. In addition, and I will admit that
I am a complete novice to electronics, I have no idea what L1 is
supposed to represent and there are no values for its size, so I
cannot even make a guess. I am hoping that those who developed the
schematic are still here.

While I do have interest in using the controller as-is (if I can get
the values needed) I am also interested in what it would take to
modify the controller for use to control universal motors because I
have need for controlling the speed of a large router, since the
TDA1085C controller IC was designed primarily for universal motors
according to Motorola's literature that I printed off.



L1 is probably just a hash filter, value not critical.

Check the application example schematic on the TDA1085 datasheet.
It's somewhat simpler than the treadmill motor controller and
presumably works. No L1 at all in that schematic, no transistors
either. The datasheet from ON Semi even has a PC board layout.
You'd probably need to change some values to work with a treadmill
motor, because the datasheet design is for a 0 to 15K RPM motor used
in a washing machine. .

There's another chip, the TDA1185A, that is designed for control of
universal motors with no tacho feedback, but I think it's no longer in
production. You might find some still floating around with some
diligent netsurfing. I have a few of them in my goodiebox I'm
saving for sewing machine speed controls (Singer Featherweight and
Singer 401) when I get around to it. One is reserved with Fitch's
name on it for his Singer Featherweight when he gets around to it.
Nothing Is Urgent.

You can buy a 15-amp router speed control for about $25 from Rockler.
It's probably not as good as something based on a TDA1185, but it
works better than I expected it would. It claims to employ some
voltage feedback speed sensing. I sure don't see it in the extremely
simple circuit, but Jeff Wisnia recalled a similar circuit and
reference to voltage feedback in the old GE SCR Manual circa late
'60's or early '70's. I found the circuit in my old SCR manual and
that indeed is what they're doing. It's not nearly as "stiff" as a
control would be with tacho feedback or current sensing as the
TDA1185 employed, but it's suprisingly good for such a simple circuit.

The best speed control would be achieved if you could devise a way to
add a tacho speedsensor to your router.
  #5   Report Post  
Mark
 
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Default Treadmill motor controller schematic at dropbox retired

This really isn't a good controller for a lot of motors - it was
matched to the original GE open frame AC/DC motor, and has soft start
which will fight with any soft-start router. The values for time
delay can be changed (prob'ly in the drop box), but I'd go for a
dedicated speed control. I CERTAINLY wouldn't try to BUILD the
one shown....

Harbor Freight had their 25.00 control on for 12 dollars recently...
/mark


Richard J Kinch wrote:

Paul Probus writes:

I have printed off the pdf version of the treadmill motor controller
schematic at the dropbox retired files.


URL?



  #6   Report Post  
Paul Probus
 
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Default Treadmill motor controller schematic at dropbox retired

Thank you for your response Wayne. I heard from a Rich D. who emailed
me directly. I had not realized that this was a reverse engineering
project. I thought it was a controller that was hashed out based
around the TDA1085C. As far as the labelling, perhaps it is one the
original DXF file, which the AutoCAD that I have at work cannot open,
but I opened the GIF and the PDF files and R2 and R4 as well as many
other components do not have values (none of the diodes and neither of
the transistors, for example), at least none that I can pick out.

My hope was to be able to use another kind of feedback vs. the
tachometer, such as back EMF sensing or perhaps a hall sensor to sense
current, however, not being very electronically inclined, I don't know
if those ideas would work.

Thanks for the respose,
Paul

Wayne Cook wrote in message . ..
On 5 Mar 2004 11:57:16 -0800, (Paul Probus)
wrote:

I have printed off the pdf version of the treadmill motor controller
schematic at the dropbox retired files. As I was looking it over, I
saw that there are some components that aren't labeled as to what
values they should be. For example, R2 and R4 are not labeled what
their resistance values should be. In addition, and I will admit that
I am a complete novice to electronics, I have no idea what L1 is
supposed to represent and there are no values for its size, so I
cannot even make a guess. I am hoping that those who developed the
schematic are still here.

I'm still here but I'm pretty far from a expert compared to most of
this group. I just reverse engineered the schematic from the board.

As for the values of R2 and R4 they should be on the schematic. At
least they're on the copy that I've got in front of me right now
(you're lucky that I just cleaned up my office and happened to find my
copy a couple of days ago). According to this one R2 is 4K and R4 is
4.74K.

L1 is a torrodial choke and I've not got any clue what it's rated
at. It is one of several components on the board that would be
difficult to source but could probably be worked around by somebody
with more electronics engineering experience than I have.

Keep in mind that there's a resister not shown on the schematic and
not obvious when looking at the board. It's in the form of one of the
traces on the board itself. It snakes around to make for a low value
high capacity resistor in the power portion of the circuit.



While I do have interest in using the controller as-is (if I can get
the values needed) I am also interested in what it would take to
modify the controller for use to control universal motors because I
have need for controlling the speed of a large router, since the
TDA1085C controller IC was designed primarily for universal motors
according to Motorola's literature that I printed off.


The big problem you'll have is that this controller needs a
tachometer on the motor to function properly. That might be hard to
add to a router.

The fact is that I'm not to one who came up with any of the
modifications to the board. I just had the time to make up the
schematic by tracing the board (wish I had that kind of free time now
days). I then posted it and let others do the figuring on how to
modify it.

Wayne Cook
Shamrock, TX

  #7   Report Post  
Paul Probus
 
Posts: n/a
Default Treadmill motor controller schematic at dropbox retired

Don,

Yeah, it sounds like the 1185A may be the one I need for my
application. As I mentioned in my reply to Wayne Cook, I was hoping
to use a different type of feedback than a tachometer, but it may not
be possible for the 1085C. I have looked deeply at the schematic that
Motorola/Onsemi provide with the literature on the 1085C. The problem
I have, being electronics illiterate (I can follow a schematic and
make up the circuit from the schematic, I cannot design a schematic),
is to provide the necessary potentiometer speed control/ramp function
that is only shown in the diagram as a "black box" with 4 switches. I
also am unsure of what component ratings will change because the
router I have says that it is rated for 3 hp, and can pull a max of 19
amps. This is why I am leary of the ready made speed controls, as
they are limited to 15 amps.

I have Richard (?) Gottliebs book on motors and controllers and there
is a nice SCR based controller that I was going to go with, as it has
back emf sensing feedback, however, the thought of softstart with the
1085 based speed control seemed like a better way to go, if I can get
it figured out.

Paul

Don Foreman wrote in message . ..
On 5 Mar 2004 11:57:16 -0800, (Paul Probus)
wrote:

I have printed off the pdf version of the treadmill motor controller
schematic at the dropbox retired files. As I was looking it over, I
saw that there are some components that aren't labeled as to what
values they should be. For example, R2 and R4 are not labeled what
their resistance values should be. In addition, and I will admit that
I am a complete novice to electronics, I have no idea what L1 is
supposed to represent and there are no values for its size, so I
cannot even make a guess. I am hoping that those who developed the
schematic are still here.

While I do have interest in using the controller as-is (if I can get
the values needed) I am also interested in what it would take to
modify the controller for use to control universal motors because I
have need for controlling the speed of a large router, since the
TDA1085C controller IC was designed primarily for universal motors
according to Motorola's literature that I printed off.



L1 is probably just a hash filter, value not critical.

Check the application example schematic on the TDA1085 datasheet.
It's somewhat simpler than the treadmill motor controller and
presumably works. No L1 at all in that schematic, no transistors
either. The datasheet from ON Semi even has a PC board layout.
You'd probably need to change some values to work with a treadmill
motor, because the datasheet design is for a 0 to 15K RPM motor used
in a washing machine. .

There's another chip, the TDA1185A, that is designed for control of
universal motors with no tacho feedback, but I think it's no longer in
production. You might find some still floating around with some
diligent netsurfing. I have a few of them in my goodiebox I'm
saving for sewing machine speed controls (Singer Featherweight and
Singer 401) when I get around to it. One is reserved with Fitch's
name on it for his Singer Featherweight when he gets around to it.
Nothing Is Urgent.

You can buy a 15-amp router speed control for about $25 from Rockler.
It's probably not as good as something based on a TDA1185, but it
works better than I expected it would. It claims to employ some
voltage feedback speed sensing. I sure don't see it in the extremely
simple circuit, but Jeff Wisnia recalled a similar circuit and
reference to voltage feedback in the old GE SCR Manual circa late
'60's or early '70's. I found the circuit in my old SCR manual and
that indeed is what they're doing. It's not nearly as "stiff" as a
control would be with tacho feedback or current sensing as the
TDA1185 employed, but it's suprisingly good for such a simple circuit.

The best speed control would be achieved if you could devise a way to
add a tacho speedsensor to your router.

  #8   Report Post  
Wayne Cook
 
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Default Treadmill motor controller schematic at dropbox retired

On 8 Mar 2004 04:26:00 -0800, (Paul Probus)
wrote:

Thank you for your response Wayne. I heard from a Rich D. who emailed
me directly. I had not realized that this was a reverse engineering
project. I thought it was a controller that was hashed out based
around the TDA1085C. As far as the labelling, perhaps it is one the
original DXF file, which the AutoCAD that I have at work cannot open,
but I opened the GIF and the PDF files and R2 and R4 as well as many
other components do not have values (none of the diodes and neither of
the transistors, for example), at least none that I can pick out.

Ok I just checked and your right. It must of been a earlier version
which got posted to the dropbox. I was short on time when the request
for posting to the dropbox was made and didn't have time. Thus I
believe it was Don Foreman who actually did it. Before that I'd just
emailed it to a few people.

I just did this since surplus places where selling these controllers
with surplus treadmill motors at that time. Many people where wanting
to get rid of some of the features (primarily the return to zero speed
before restarting) but nobody had a schematic for it. Thus I reverse
engineered this schematic so that the real electronics guru's could
figure out how to modify it. I'm more in your category in that I can
read a schematic and figure a few things out but starting from scratch
is way beyond me.

My hope was to be able to use another kind of feedback vs. the
tachometer, such as back EMF sensing or perhaps a hall sensor to sense
current, however, not being very electronically inclined, I don't know
if those ideas would work.

To my knowledge they won't work with this chip.


Wayne Cook
Shamrock, TX
http://members.dslextreme.com/users/waynecook
  #9   Report Post  
Paul Probus
 
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Default Treadmill motor controller schematic at dropbox retired

Wayne,

I understand. I was not trying to prove the point. I thought that
the missing values would be on the DXF file, since the DXF file I was
assuming was the original file, but was lost in subsequent
translations to other formats. I also thought the DXF format was
supported by AutoCAD, if it is it is not supported by the one at work,
so I was unable to check that file.

Anyway, I believe that this circuit is probably not going to work for
me, although I may be able to get some ideas for what I want/need to
do to use the TDA1085C.

Thanks,
Paul
  #11   Report Post  
Don Foreman
 
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Default Treadmill motor controller schematic at dropbox retired

On 8 Mar 2004 04:39:38 -0800, (Paul Probus)
wrote:

I
also am unsure of what component ratings will change because the
router I have says that it is rated for 3 hp, and can pull a max of 19
amps. This is why I am leary of the ready made speed controls, as
they are limited to 15 amps.

I was in error when I said my "15 amp" speed control was from
Rockler. It's this one:
http://www.mlcswoodworking.com/shops.../speedcon.html

It actually uses a 40-amp 600-volt triac; ST partnumber BTA41-600B
Data sheet at
http://eu.st.com/stonline/books/pdf/docs/7469.pdf

I bet all you'd need to do is repackage this "15 amp" control using
a significantly larger heatsink for the triac. You'd have that issue
with any speed control you might build. It'd be easy to do with this
one because the triac is connected with wires rather than being
soldered into a printed wiring board.

Even if you do manage to zorch the triac, Digi-Key stocks this
part. It's $4.75 each in onesies.

Designing a close-loop speed control, particularly one for a
series-wound universal motor, would be a fairly ambitious project if
you don't have some familiarity with electronics and feedback control
systems.


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