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Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work. |
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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 |
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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? |
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Treadmill motor controller schematic at dropbox retired
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Treadmill motor controller schematic at dropbox retired
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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? |
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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. |
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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 |
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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 |
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Treadmill motor controller schematic at dropbox retired
On 8 Mar 2004 12:02:35 -0800, (Paul Probus)
wrote: 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. Hmm. I don't remember what I used to make it. I may of used a old free CAD program that I was playing with back then. If so DXF could of been the original. 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. Ok. Good luck. Wayne Cook Shamrock, TX http://members.dslextreme.com/users/waynecook |
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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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