HELLO, I WANT TO CONVERT ABOVE CONFIGURE MOTOR 1440 RPM TO 120 RPM ONLY BY ELECTRICAL OR ELECTRONICS SOLUTION. PLEASE ANY ONE PROVIDE ME SOLUTION AND CIRCUIT DIAGRAM FOR THAT. I DONT WANT VARIABLE SPEED CONTROLLER. I JUST MAKE ONLY ONE CONTROL OF SPEED AT TIME. SO PLEASE GIVE ME LOGIC AND CIRCUIT LOGIC ALSO.
There is no way to do that. This is an induction motor. A VFD (Variable Frequency Drive) will not work as pointed out by lunchtime_browser. You will have to use a gearbox with almost any motor to do that. If you use an induction motor (squirrel cage or AC motor), it is possible to control a 3 phase motor to lower speeds by using a VFD, that reduces the voltage and changes the frequency, but only within limits. These can be programmed to a fixed speed, but not so slow as 120 RPM. The cooling might also need to be addressed (fan too slow). Single phase (split phase) motors are more limited, whether using a centrifugal switch or not. You probably need a DC motor if you insist on no gearbox. The variable speed controller to suit this motor is just set to the speed you want. If you need a precise speed it needs a speed controller with speed sensor and feedback. Note that the mechanical power is the product of RPM and torque. The torque is more or less the same, as it is determined by the current rating. However with 120 RPM from a 1440 RPM motor the speed is only 1/12 so the power is only 1/12. Using a gearbox increases the torque and reduces the speed so the power is more or less the same. There are gearmotors for a wide range of output RPM. A bicycle hub motor might suit if the power is in your range. Another idea is a stepper motor, which can run at these low speeds, but it does need a controller (driver) and power supply..
That is not going to work. It sounds like an induction motor. The speed is controlled by the frequency of the supply. To get a speed less than 1/10 of normal, you would need to generate a frequency less than 5 Hz. If you did that, the efficiency of the motor would be horrible. Even if you managed with that, you would still have problems. Most A.C. single phase motors rated at more than a few tens of watts use a 'centrifugal switch' to disconnect the starting windings when the motor is running. It certainly would not operate at that speed. Your motor would cook. Sorry.
