output shaft of the motor is coupled to the drive shaft 12 the motor is capable of variable speed drive as controlled by a variable speed drive circuit variable drive circuits for motor control are well known and essentially an adjustable varying speed motor is one where the speed can be adjusted variable speed motors are well known and for example motor control can be implemented by many different techniques there are control circuits which control the speed of the motor which supply a variable width and variable frequency signal which for example has a duty cycle and a frequency dependent on the current directed through the motor such control devices are implemented using current feedback to sense motor speed such circuits can control the speed of the motor by varying the pulse width as well as pulse frequency speed control by frequency variation is referred as variable frequency drive vfd the entire field of motor control is quite well known speed control can be implemented by the use of thyristors or scr 39 s and in certain situations is analogous to light dimming circuits a variable speed or vfd device accurately enables one to calculate the motor speed and torque as shown in fig1 there is a processor 25 which essentially may be included in the variable speed drive circuitry 21 and is responsive to motor rotation or torque the function of the processor as will be explained is to solve or process the affinity laws governing the operation.