electric motor setup for 1rpm

[Reloadron]

does a speed controller act as an inverter?

No, speed controllers can work several different ways depending on the motor. Also, finding a motor and speed controller that will run on 120 VAC with a line cord shouldn't be a problem. I saw back there you mentioned I believe 30 to 100 RPM? What was that about? Not a problem but thought you wanted 1 RPM? You can find small very light application 1 RPM AC synchronous gear motors pretty cheap. They won't drive much.

Ron

 

[KeepItSimpleStupid]

So, what do you really need? Torque?

You can measure Torque with a spring scale. Distance combined with force to pull.
I wanted to know how much torque, I needed to pull on curtain. Used caned weights (canned goods) until it moved, then the gear size I used. So, you get ft-lbs or in my case inch-lbs.

 

[daviddil]

Thank you -

How do I know what motor this speed controller will cover? We're now looking at up to 1.2 amp 1/8" hp 130v DC. Also note it states there is a brake - does this require a special motor?

**broken link removed**

 

[KeepItSimpleStupid]

When you control a DC motor you basically have 4 modes:
FWD
REV
BRAKE
COAST

Motor control is usually done with a circuit called an H-Bridge. It looks like transistors or FETS arranged in an "H" configuration. It allows reversal of polarity with a single supply. "Braking" basically means, turn the motor off, and at that point it;s acting as a DC generator. If you vary the load, or even short the motor it stops nearly instantaneously. Coasting is basically just turning the motor off.

It;s easier to provide a NOT ENABLE and a DIRECTION input to implement FWD/REV. Not enable is an artifact because most processors (that may provide the PWM) on power up are cofigured as inputs. You generally don;t want the motor to move until the processor has completed it's initialization cycle.

real TTL logic ( a common logic form used to float high), so an unconnected input (the NOT ENABLE) signal would not move the motor.

BRAKE is often eliminated as a control mode.

PWM is called pulse width modulation. It generally allows the full torque at low speeds because the motor sees close to it's designed voltage. Some PWM controller won;t reach 100%. They might reach 98%. EXTREMELY slow speeds depend on what it takes to overcome frictional losses.

PWM varies the duty cycle On/Off time in % that the motor sees.

Single direction control is obviously cheaper.

 

[Reloadron]

Thank you -

How do I know what motor this speed controller will cover? We're now looking at up to 1.2 amp 1/8" hp 130v DC. Also note it states there is a brake - does this require a special motor?

**broken link removed**

What you have linked to is an old Bodine ASH series motor speed controller. These were used with the older Bodine brush type DC motors. There is a 4 wire cable that will exit the unit. Two wires are a fixed DC voltage around 90 volts and I am working from memory, and two wires with an adjustable DC voltage out. Two wires are for the motor field winding and two are for the armature winding. I can't remember if the field is fixed voltage and the armature is varied or vise verse. I think with the ASH series Bodine controllers the higher the ASH Model Number the higher the current out for the higher HP motors. It's been maybe 15 plus years since I used those old motors. At one time I actually had manuals which are now long gone. The FWD and REV merely reverses the + and - outputs to either the field or armature. The Brake I think simply removes power from the armature or field and shorts the motor winding. Again, it has been a long time. The controller you linked to is designed for brush type Bodine DC motors. I don't know if it will work with other similar designed motors.

Ron