Dc Motor Drive Basic Questions

From here, best place to go is where you got the motor and controller, see whether they still have the control head with the keypad...

That's a serial connection, so (unless anyone knows better) the board's expecting codes, not simple voltages - I use a similar board from a Reebok treadmill, it too uses a serial link so I've had to keep (for now) the display and pushbuttons to use it as a DC motor test rig :(

Otherwise - the board's a decorative ornament, nothing more, you may be best getting a KB or similar motor controller to replace it?

Dave H. (the other one)
 
The control head and keyboard were not with the motor at the scrap yard so...... The Pacific Scientific motors with high amp ratings are pretty common from looking at ebay, the downside is no one makes a controller for them that is in the price range of the Minarik ($100+-). I've spoken to a rep from Galco and Minarik itself, but if the motor is higher than 15amps and 115ac input controllers are not readily available. I asked the Minarik rep about using the Minarik 2300 series and using the voltage limiter to keep the power at 10 amps, he seemed to think it was risky, the controller still might get fried. I don't know if the this motor on my lathe would ever get close to overload but I doubt it(right?).

Looked at the KB controllers as well, they have models with fuses. Could I use a lower rated fuse so it would blow if an overload(above the 10amps) was sent to the controller? I will talk to KB about this.

Edit: just got off the phone with KB tech, he seemed to think that by limiting the motors start acceleration to a slow ramp up speed it would greatly decrease the chance of damaging the controller(KBCC125)k, thoughts?? Of course no guaranties using this.
link to KBCC125
http://www.galco.com/buy/KB-Electro...xjsuVyb0fNil6A6x9-aRgcV2wV26-FGk8IaAtmQ8P8HAQ

Any input is always welcome,

Brian
 
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calstar said:
The control head and keyboard were not with the motor at the scrap yard so...... The Pacific Scientific motors with high amp ratings are pretty common from looking at ebay, the downside is no one makes a controller for them that is in the price range of the Minarik ($100+-). I've spoken to a rep from Galco and Minarik itself, but if the motor is higher than 15amps and 115ac input controllers are not readily available. I asked the Minarik rep about using the Minarik 2300 series and using the voltage limiter to keep the power at 10 amps, he seemed t

Any input is always welcome,

Brian
Click to expand...

You have the motor with the original controller.
Perhaps i am misunderstanding but why do you require the "control head and keyboard"?
I have 4 TMMs on the shelf with the circut boards, and the slider for the variable speed control.
The user console has nothing worth salvaging. Just mho.
 
LucknowKen said:
Perhaps i am misunderstanding but why do you require the "control head and keyboard"?
Click to expand...

Hi Ken,

On your motors/controllers the speed control is a simple slide pot.

On Brian's they used a digital serial interface between the user touch-pad and the motor controller circuit board. Who knows what the protocol of those serial messages is and how to "fake" them?

I am currently facing the same problem with the treadmill parts I just picked up this week. I did get the entire machine and therefore have the touch-pad too, but it is unclear how to use the motor and controller without the touch pad. I hope to have a closer look at the works this weekend and try to determine if/how I can make these parts work for my project. I would prefer to lose the serial control interface and find a way to wire in a simple speed pot.

-brino
 
brino said:
Hi Ken,

On your motors/controllers the speed control is a simple slide pot.

On Brian's they used a digital serial interface between the user touch-pad and the motor controller circuit board. Who knows what the protocol of those serial messages is and how to "fake" them?

I am currently facing the same problem with the treadmill parts I just picked up this week. I did get the entire machine and therefore have the touch-pad too, but it is unclear how to use the motor and controller without the touch pad. I hope to have a closer look at the works this weekend and try to determine if/how I can make these parts work for my project. I would prefer to lose the serial control interface and find a way to wire in a simple speed pot.

-brino
Click to expand...

Thanks for answering the question! Brian
 
Hey guys: Thanks for the info. The Johnson motor i have (pictured) indeed has a console with ribbon cables.
Two cables leading to two touch pads, one pad for speed the other incline.
12 settings or buttons each side. 10 leads on each ribbon.
Johnson.JPG Minarik.JPG
I better hang on to the console.
Lken
 
First I would warn you off of a "potentiometer" for speed control. It actually would be a rheostat and have to carry motor current. 10 Amps is a pretty big rheostat, especially when you would have to purchase it. And it gets very hot while running slow.

The motor alone will run at base speed with no more than a rectifier in the line side.(preferably a bridge, about $7US) A reversing switch would be the DPDT switch, preferably with a center off position as well. The rectifier will be about an inch and an eighth square. It should be rated well above what the motor pulls. 40 Amp at 600 Volt is a stock item in my shop for similar applications. We are dealing with line voltage here. See an entry in the shop electrical/wiring section for a link.

Now, to speed control. A little(?) research will be in line. If it was me(!), I would use a high current pass element as the main element with a lower current controller. A model train power pack is a good starting point, but with much higher current capacity. They're only rated for a couple of amps. A good choice here would be 2N6284 and 2n6287 to build a bridge amplifier. Rated at 20 Amps continuous and 40 Amps surge. With, of course, a good heat sink.

If you get the controller board up and running, that would do for speed control. If it was mine, I would start from scratch and make my own (simpler) version. Everything recent is made computer control for cost and simplicity of manufacturing purposes. Since politics are "verboten" here, I won't go into that subject any further.

The motor is just a motor. In this case, applied voltage controls the speed. The big issue to note is that torque falls off at a distressing rate as speed is reduced. I'm babbling now, hope this gives some direction to your search.
 
You are over think this i have done several of these, get tread mill speed control off ebay, m60 which is big enough to run that motor, a lot cheaper and it works good.
 
Figuring out the serial protocol could be quite the task unless you're experienced in that kind of thing and have the necessary test equipment. As others have said the Minarik speed control isn't sufficient; I would look for an MC-60 treadmill controller on ebay... cheaper than the Minarik and sufficient capacity. All you need is a potentiometer with the MC-60 to set the speed. Or an MC-2100 controller, though that's somewhat more difficult to interface with as it requires a PWM signal to set the speed. Fortunately others have done that work already, info in the thread I started recently.
 
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