In this post I have explained a few circuit diagrams for building AC motor speed controller circuits using back EMF concept. Working Principle of AC Motors So now, all those home type appliances like electric drill machines, sander machines, sewing machines, food mixer machines, etc. they all are mostly using that AC motor which is […]
Motor Controller
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 […]
Single Phase Variable Frequency Drive VFD Circuit
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 […]
Climate Dependent Automatic Fan Speed Controller Circuit
The following circuit of a temperature or climate controlled automatic fan speed regulator circuit was requested by one of the followers of this blog Mr.Anil Kumar. I have explained more about the proposed design. The Design As can be seen in the given diagram, a very simple concept has been implemented in the proposed design of a climate controlled […]
How to Control Motor with a Cell Phone
In the following post I have explained a very simple circuit idea which can be used for controlling a motor’s rotational direction i.e. for moving it either clockwise or anticlockwise through alternate miss calls from your cell phone. The Circuit Concept I have already discussed a novel cell phone controlled remote switch circuit where the […]
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, […]





