Contact mics can be used to sense unusual sounds when attached to various surfaces.It also Produce sound when voltage is applied to it.With the help of a basic Pre-amp circuit it can also be used to Electrify an Acoustic Guitar, where amplification is a must. Written and Submitted by: Ajay Dusa Piezoelectric Disc as the […]
Audio and Amplifier Projects
Buzzer with Incrementing Beep Rate
In this post I have explained a buzzer circuit with an incrementing beeping rate, which can be used in critical warning signalling applications. The idea was requested by Mr. Lee. Buzzer with Progressive Beep Rate Could you help me with a circuit. I’ve been trying to find but so far had no luck! I need […]
Simple Surround Sound Decoder Circuit
This article is written with an intent to explain in detail behind the making of a simple surround-sound decoder circuit. By: Dhrubajyoti Biswas Overview The concept of the decoder was first introduced by David Hafler in the 70s. His research illustrates the way to use two speakers as rear speakers on a surround system. The […]
How to Make Ultrasonic Directive Speaker Circuit
In this post I have explained the construction of a ultrasonic directive speaker system also called parametric speaker which may be used to transmit an audio frequency over a targeted spot or zone such that the person situated exactly at that spot is able to hear the sound while the person next to him or […]
Laughter Sound Simulator Circuit
As the name suggests, this device generates electronic sound, resembling human laughter. BASIC DESIGN To enable the circuit start the proposed operations, it must have a fundamental sound input or frequency for processing. This basic frequency is established through a simple oscillator operating at 1 kHz frequency. The next, requirement would be to process this […]
Make this Musical Greeting Card Circuit
The presented circuit of a musical greeting card circuit was requested by one of the keen readers of this blog, so I designed this interesting little circuit, which is simple and easily gets embedded inside any standard greeting card fold. Looking at the given circuit diagram, we see a design consisting of a very few number of components, rigged […]





