In this post I have explained a single phase variable frequency drive circuit or a VFD circuit for controlling AC motor sped without affecting their operational specifications. What is a VFD Motors and other similar inductive loads specifically do not “like” operating with frequencies that might be not within their manufacturing specs, and tend to […]
Newly Updated Circuit Projects:
Motor Protection Circuits – Over Voltage, Over Heat, Over Current
In this post I have explained a few DC motor protection circuit from harmful conditions like over voltage and under voltage situations, over current, overload etc.. DC motor failures are commonly experienced by many of the users, especially in places where the relevant motor is run for many hours a day. Replacing motor parts or […]
Washing Machine Motor Agitator Timer Circuit
The article details a circuit design for controlling a washing machine motor agitator through a preset time sequence which also includes an alternate reversing of the motor rotation. The circuit was requested by Mr. E.Rama Murthy. Technical Specifications I am having old washing machine which is good working till now. Of late, its PCB has […]
Treadmill Motor Speed Controller Circuit
In this post I have explained a simple, accurate, high torque treadmill motor speed controller circuit which may be effectively installed in similar units for acquiring PWM controlled variable speed feature. The idea was requested by Mr. Samuel. Technical Specifications I’ve a treadmill whose power failed completely…it had been imported from china and it’s like […]
Water/Coffee Dispenser Motor Circuit
In this article I have explained a protection circuit which may be used for preventing a “dry run” situation in mini coffee dispenser motor pumps, by sensing the slight difference in its wet and dry current consumption levels. The idea was requested by Mr. Ken Adler. Technical Specifications I read with great interest your post titled, […]
How to Make a 3 Phase VFD Circuit
The presented 3 phase VFD circuit (designed by me) can be used for controlling the speed of any three phase brushed AC motor or even a brushless AC motor. The idea was requested by Mr. Tom Using the VFD The proposed 3-phase VFD circuit can be universally applied for most 3-phase AC motors where the […]





