Non-Contact AC Mains Tester Circuit

The simple transistor based non contact AC mains tester circuit will allow you to test the presence of mains AC hum from a distance of about 3 inches. The LED and an optional buzzer will provide the required mains phase presence.   How the circuit Works As we can see in the above figure, 3 […]

Read More »

Hi-Fi Bass, Treble, Presence Tone Control Circuit

In this post we learn how to make a simple yet Hi-Fi super tone control circuit featuring adjustable bass, treble, and presence control circuit using potentiometers and processed using opamps. This specific tone control features a couple of control knobs or pots which enable you to vary the presence of bass and treble within an […]

Read More »

Single chip Quadraphonic Amplifier Circuit – For Making Home theater Systems

In this post we learn how to make a simple single chip quadraphonic amplifier circuit which can drive four loudspeakers through 4 separate input channels, this IC becomes ideally suitable for making small compact home theater systems. This specific amplifier offers, with a single integrated circuit and handful of supplemental components, four independent amplification channels […]

Read More »

Digital Temperature Indicator Circuit

This explained digital temperature indicator circuit had been created for computing the heatsink temperature of a big over 1kva power amplifiers, however it may, obviously, be applied for other power amplifiers and even for various other purposes. The thermometer would not just display the heat range of the heatsink on a couple of displays, nevertheless […]

Read More »

Transistor Current Gain Tester Circuit – hFE Tester

This hFE or transistor forward gain tester is intriguing due to its ease-of-use and because it allows the use of both PNP and NPN transistors to be assessed. Additionally more the measuring becomes self-governing of the supply voltage of the tester. As the picture displays, the base current of the transistor under check moves through […]

Read More »

Simple Microphone (MIC) Amplifier Circuits using Transistors

The first one is a single transistor simple microphone circuit, very simple to hook up using an electret microphone or MIC and an audio amplifier. Typically the 10K resistor within the microphone’s positive port offers this specific vital voltage for the procedure. The capacitor of 100nF on that particular network prevents the DC component of […]

Read More »

Simple 220V Ding Dong Bell Circuit

The post explains how to make a simple 220V mains operated ding dong bell circuit which will generate a powerful ding dong sound each time someone presses the bell push button. This bell produces the classic “Ding-Dong” bell sound but does not use mechanical parts. With an integrated one designed for such use and some […]

Read More »

5 Input Microphone Mixer Amplifier Circuit using a Single IC

This circuit enables the user to blend in one 5 separate signals from 5 dynamic low-impedance microphones and a couple of external auxiliary inputs, which can be electret-type microphones or even actually amplified inputs for example those from your CD player or a phone. The circuit really is easy and is made up of feedback […]

Read More »

220V Light Dimmer Circuit using Push Button Control

The following circuit can be effortlessly used for dimming a 220V or 120V mains operated lamp or fan using a single push button operation. Referring to the given figure, the IC ┬áNB7332 is an advanced frequency generator which changes its high frequency pulse range to alter the triac’s switching pattern such that for lower power […]

Read More »

Cellphone Power Bank Circuit you can Make at Home

This simple cellphone power bank circuit charger can be built at home and used for emergency charging your cell phone anytime anyplace regardless of an AC mains outlet or input availability. The idea is all about using a 4 AAA N-Cd cells in series and then keeping it fully charged through a suitable SMPS charger […]

Read More »