This fan speed controller works by sensing the temperature of the engine and is accordingly used for the triggering. As the temperature increases so does the speed of the fan motor and vice versa. Circuit Operation Operation of the proposed temperature controlled fan may be understood as follows: The speed of the DC motor alters […]
Archives for 2015
How to Measure Gain (β) of a BJT
In this post we’ll study a simple opamp circuit design which can be applied for measuring the beta or the forward current gain of a particular BJT in question. What is beta (β) The beta (β) is the forward current gain that every BJT inherently possesses. It determines the efficiency of the particular device in terms […]
Infrared Remote Control Safe Lock Circuit
A simple, cheap yet highly effective infrared remote control safe lock circuit can be studied in the following post. Using IC LM567 The LM567 IC is one of my favorites simply because it’s too versatile, and becomes applicable in most of the crucial circuit concepts through hassle free configurations. One such crucial yet simple IR […]
Battery Current Indicator Circuit – Current Triggered Charging Cut off
In this post I have explained about a simple battery current sensor with indicator circuit which detects the amount of current consumed by the battery while charging. The presented designs also have an auto cut off when the battery stops consuming current at its full charge level.. Why Current Drops as Battery gets Charged We […]
Up/Down LED Indicator using LM3915
This circuit can be used for moving an LED bar graph in the upward sequence or downward sequence through a couple of push button switches. The concept can be implemented for many other useful applications. Using IC LM3915 In many circuit applications we require a digitally operated control system enabling an upward or downward control […]
Borewell Motor Pump Starter Controller Circuit
In this post I have explained a circuit which controls a submersible borewell motor by operating its red (Start) and green (Stop) buttons, in response to low level, high level water conditions, and also in a condition where the motor may experience a dry run situation. The idea was requested by Mr. Vamsi. Automatic Start/Stop […]