Voltage Regulators

john July 2, 2014 5 Comments
A voltage regulator is a voltage stabilizer that is designed to automatically stabilize a constant voltage level. A voltage regulator circuit is also used to change or stabilize the voltage level according to the necessity of the circuit. Thus,...
read more

Regulated Power Supply

john June 23, 2014 14 Comments
INTRODUCTION Almost all basic household electronic circuits need an unregulated AC to be converted to constant DC, in order to operate the electronic device. All devices will have a certain power supply limit and the electronic circuits inside these...
read more

Basic Controls of a CRO

jojo September 24, 2009 6 Comments
Number of controls are required to be provided on a panel of CRO to facilitate its proper functioning. Intensity control is provided for adjustment of brightness of the spot on the screen. It is accomplished by varying the voltage...
read more

CRT-Cathode Ray Tube

jojo September 24, 2009 3 Comments
Cathode ray tube essentially consists of an electron gun for producing a stream of electrons, focusing and accelerating anodes for producing a narrow and sharply focused electron beam, horizontal and vertical deflection plates for controlling the beam path and...
read more

CRO-Cathode Ray Oscilloscope

jojo December 22, 2016 28 Comments
Introduction to CRO – Cathode Ray Oscilloscope The cathode ray oscilloscope is an extremely useful and versatile laboratory instrument used for studying wave shapes of alternating currents and voltages as well as for meas­urement of voltage, current, power and...
read more

8 function christmas lamp

john September 24, 2009 21 Comments
Description. This 8 function serial Christmas lamp controller is based on the IC UTC 8156 from Unisonic. Specially designed for the same purpose, the UTC 8156 can control the four lamps in 8 modes namely waves, sequential, slo-gol, chasing/flash,...
read more

Voice modulator circuit

admin April 7, 2010 7 Comments
Description. This is a very versatile voice modulator circuit using IC HT8950A from Holtek Semiconductors. The IC is capable of creating 7 upward or downward steps on the frequency of the input voice at a rate of 8Hz. There...
read more

Ni-MH battery charger using LT4060

john September 24, 2009 18 Comments
Description. This is the circuit diagram of a very powerful and efficient Ni-MH battery charger using IC LT4060 from Linear Technologies. In addition to Ni-MH batteries Ni-Cd batteries can be also charged by slightly modifying the circuit.For charging Ni-Cd...
read more


jojo September 23, 2009 5 Comments
Q-Meter We know that every inductor coil has a certain amount of resistance and the coil should have lowest possible resistance. The ratio of the inductive reactance to the effective resistance of the coil is called the quality factor  ...
read more

Electronic Multimeters

jojo September 23, 2009 2 Comments
Electronic Multimeters It is one of the most versatile general purpose instruments capable of measuring dc and ac voltages as well as current and resistances. The solid-state electronic multimeter (or VOM) generally consists of the following elements. A balanced...
read more


jojo January 18, 2011 No Comments
Electronic Galvanometers A vacuum tube or transistor amplifier, followed by a milli-ammeter may be employed as a detector. Some of such devices have arbitrary scale values, sometimes with variable gain, and are designed simply as balance indicators. The sensitivity may...
read more

Balanced Bridge Voltmeters

jojo September 23, 2009 No Comments
Balanced Bridge Voltmeters Such voltmeters can be used for measurement of both dc and ac voltages and are very popular. These voltmeters are available in both versions, vacuum tube type and transistorized type and are described below: (a) Balanced...
read more

RMS Reading Voltmeter

jojo September 23, 2009 1 Comment
True RMS Reading Voltmeter RMS value of the sinusoidal waveform is meas­ured by the average reading voltmeter of which scale is calibrated in terms of rms value. This method is quite simple and less expensive. But sometimes rms value...
read more

AC Voltmeters

jojo September 23, 2009 2 Comments
In electronic ac voltme­ters input signal is firstly rectified and then sup­plied to the dc amplifier, as shown in figure. Sometimes signal is firstly amplified by ac amplifier and then recti­fied before supplying it to dc meter, as shown in...
read more

DC Voltmeters

jojo September 23, 2009 2 Comments
DC Voltmeter Block Diagram DC voltmeter mainly consists of a dc ampli­fier apart from the attenuator, as shown in figure. DC Voltmeter Block Diagram DC voltmeters can further be divided into two categories. 1. Direct Coupled Amplifier DC Voltmeter....
read more

Electronic Voltmeters

jojo September 22, 2009 1 Comment
In all electronic voltmeter circuits the principle involved is that an indication on a permanent magnet moving coil instrument (normally abbreviated as PMMC or D’Arsonval movement) proportional to the input voltage is obtained by means of amplification in one...
read more

Voltage Controlled Oscillator

jojo March 18, 2014 4 Comments
VCO (Voltage controlled oscillator). Voltage controlled oscillator is a type of oscillator where the frequency of the output oscillations can be varied by varying the amplitude of an input voltage signal.Voltage controlled oscillators are commonly used in frequency (FM),...
read more

Function Generators

jojo February 25, 2010 9 Comments
A function generator is a signal source that has the capability of producing different types of waveforms as its output signal. The most common output waveforms are sine-waves, triangular waves, square waves, and sawtooth waves. The frequencies of such...
read more

PUT Controlled Sawtooth Wave Generator

jojo February 25, 2010 No Comments
A PUT controlled sawtooth generator circuit is shown in figure. When power is first applied, the programmable unijunction transistor (PUT) is off. The capacitor C begins to charge up and the output voltage rises. This continues until the output...
read more

Sawtooth Wave Generator

jojo March 25, 2014 6 Comments
Sawtooth wave generator. Many people often get confused between sawtooth wave and a triangular wave. Sawtooth waveform is a type of linear non sinusoidal waveform with a triangular shape in which the rise time and fall time are different....
read more

Triangular waveform using Schmitt Trigger

jojo February 25, 2010 1 Comment
How to make a Triangular waveform using Schmitt Trigger and Integrator ? Another triangular-waveform generator that needs fewer components is shown in figure. The arrangement consists of a non-inverting Schmitt trigger Ax and an integrator A2. The output of...
read more

Triangular Wave Generator

jojo March 25, 2014 9 Comments
Triangular wave generator using opamp. This article is about a triangular wave generator using opamp IC. Triangular wave is a periodic, non-sinusoidal waveform with a triangular shape. People often get confused between triangle and sawtooth waves. The most important...
read more

Super bright LED night light

john October 15, 2010 27 Comments
Description. Here is the circuit diagram of a super bright LED night lamp that can be operated from the mains supply. Bridge D1 is used to rectify the AC mains voltage. The capacitor C1 and resistor R1 forms the...
read more

Wireless mains voltage tester.

john September 22, 2009 18 Comments
Description. This circuit can be used to test whether mains voltage is present or not without having electric contact with mains line. The CMOS IC CD4033 is the heart of this circuit. The CD4033 consists of a 5 stage...
read more