A sine wave generator is actually a sine wave oscillator circuit which generates an exponentially rising and falling sinusoidal waveform. The 9 simple sine wave generator circuits presented in the following article are easy to build, since they incorporate a small number of ordinary electronic components, and can be used for generating an exponentially varying […]
Circuits
3 Best Joule Thief Circuits
A joule thief circuit is basically an efficient, self-oscillating voltage booster circuit, built using a single transistor, resistor and an inductor, which can boost voltages as low as 0.4 V from any dead AAA 1.5 cell, to much higher levels. Technically it may seem impossible to illuminate a 3.3 V LED with a 1.5V source, […]
Phase Shift Oscillator Circuits – Wien-Bridge, Buffered, Quadrature, Bubba
A phase-shift oscillator is an oscillator circuit designed to generate a sinewave output. It operates with a single active element such as a BJT or an op amp configured in an inverting amplifier mode. The circuit arrangement creates a feedback from the output to the input through using an RC (resistor/capacitor) circuit arranged in a […]
Transformerless LED Bulb Circuits using Capacitors
In this post I have elaborately explained how to build simple transformerless LED bulb circuits using many LEDs in series and powering them through current controlled capacitive power supply circuit. Safety Note: These circuits operate directly from mains AC voltage without galvanic isolation, meaning live components carry high voltage when energized. Standard electrical safety practices […]
3 Best Transformerless Inverter Circuits
As the name suggests, an inverter circuit that converts a DC input into AC without depending on an inductor or a transformer is called a transformerless inverter. Since an inductor based transformer is not employed, the input DC is normally equal to the peak value of the AC generated at the output of the inverter. […]
AC Motor Speed Controller Circuits using Back EMF
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 […]





