开云体育

Hello.

I'm trying to run a 24v D/C gear motor with the ability to control RPM
between 20 - 35. Continuous operation, 9 hours per day.

50 inch oz. of torque. Looking at the Molon C15, or other type of 'gear
motor' that I can attach a nose gear to the shaft. Speed control is
mandatory.

My problem is in the controller itself. EXPENSIVE. I'm now looking into
model railroad controllers to do the job. They are bigger than the normal
KB controllers, but half the cost.

Can anyone suggest a way to control speed of a D/C motor, inexpensively? It
cannot be 'Mickey mouse' because it's part of a prototype machine I'm
building, which hopefully will sell to the public. Is it a fact of life
that it just costs to cut the voltage?

Thanks.

Gary

Can anyone suggest a way to control speed of a D/C motor, inexpensively? It
cannot be 'Mickey mouse' because it's part of a prototype machine I'm
building, which hopefully will sell to the public. Is it a fact of life
that it just costs to cut the voltage?

Well, you could do some experiments with pulse width modulation. I hear that is used quite a bit for pulse DC motor control. You can make this with a 555 timer circuit like this:



You can set up a voltage divider with a pot in the middle as your control resistor to get the exact range you want.

This may seem just a little 'mickey mouse' but it works.

If you want non pulse DC (I suppose for higher current motors that might be problematic...????) you could use an adjustable voltage regulator. I know most manufacturers have these. National Semiconductor has lots of info on their webpage including PDF files and application notes and circuits.

You could design your own voltage controlling board for the motor speed and have it custom made, but that could be just as expensive as buying the premade ones.

I know your pain, though. There's a few machines I make at work that use DC motor control boards for adjusting conveyor belt speed. Very expensive.

-Tavys