Free Electronic Circuit Design
Introduction: PWM (Pulse-Width Modulation) for Digital Audio Conversion Pulse width modulation (PWM) technique has been widely used for converting digital audio stream into audio signal since it is very simple and easy to implement. Many low-cost micro controllers include dedicated PWM controllers as their standards, and many engineers use it for many purposes. In this article, we present the solution […]
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A. Introduction: The 936 Soldering Station Series in The Market With the popularity of specific brand’s soldering station labeled with 936-series, many manufacturers (mostly Chinese companies) make benefits by producing the counterfeit products with the generic names “936 series” soldering station. It is a good things that their parts are widely available on the online marketplace, as shown in the […]
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This flip-flop circuit uses one potentiometer and one capacitor as the frequency determining components. The assembled circuit is shown in the Figure 1, and the schematic diagram of the circuit is shown in the Figure 2. The circuit consists of one integrated circuit of inverter gates (4069 CMOS or 74C04), one electrolytic capacitor, two resistors, two LEDs, and one potentiometer. […]
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Making a linear voltage regulator using 78XX integrated circuit series is very easy, it needs only one or two additional components to make the integrated circuit chip works. The problem arises when we need a custom voltage specs for the output, since they come in discrete fixed voltage variation (specified by XX parameter printed in the body of the IC […]
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The previous music-controlled disco light controllers, the audio-controlled disco light controller circuit and hi-lo (treble-bass) disco light controller have some features and drawbacks. The first one features high voltage drive, enable the circuit to drive 220VAC lamps, and the drawback is that it has only one way (single channel control). In the other side, the second version has two-way (bass […]
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Low Power Requirement of Indication and The Solution Visual indication using light emitting diode becomes very common, because LED technology offer many benefits: low power consumption, durable, and cheap. Some indication must be able to draw strong attention, or at least it must be very clear to read whether its state is on of off. In some application, the requirement […]
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To get various characteristic of an auto wah/quack effect, we need a flexible control of the envelope detection characteristic. Some playing styles need slow attack but fast decay, but some others don’t. Employing the envelope detector circuit presented in our previous article [Ref 1], but with some modification to make it single supply operation. Here we present the improvement of […]
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Introduction to Envelope Detector Circuit Envelope detector circuit is used to get the amplitude profile of a signal. Some important properties of an envelope detector are attack or rise time and decay or release time. In the Figure 1, a signal is plotted in blue, and the detected envelope is plotted in black. Since it employs capacitor for filtering inside […]
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Introduction to Automatic Wah/Quack Effect Automatic wah/quack effect gives a similar effect with the manual version (reference [1]), but without the need of any pedal to manually control the frequency/tonal sweep. This automation is made possible by detecting the envelope signal of the instruments audio signal, and use it to control the filter to produce center frequency sweep, producing audio […]
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A type of guitar effect pedal that produce “wah”- or “quack”-like sound, which is similar to the crying sound of a baby is called wah-wah pedal, or just wah pedal. The effect is produced by filtering the musical instrument through a band-pass filter, which the center of its peak frequency is swept from low to high, mimicking audio tonal transition […]
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Introduction: What is Fold-Back Distortion? I was introduced to a term of “fold-back distortion” in the past by an article from an old book which I forget what the title is, but the book contains schematic diagrams of many circuits collected from old publication of Elektor magazine (www.elektor.com). The article presents the circuit’s schematic diagram and how it works. I […]
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Introduction While almost every audio equipments pay whatever it cost to minimize distortion, this kind of device does the opposite: distortion effect for electric guitar. Many methods have been implemented in producing a distorted signal from electric guitar pick-up, such as over-driven vacuum tube, solid-state (transistor), or diode clipper. The simplest form is passive diode clipper, which is implemented as […]
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