So far, we have considered the oscillators which use L-C tuned circuit that causes a phase shift of 180 ° due to inductive or capacitive coupling in addition to a 180 ° phase shift produced by the transistor itself. The oscillators employing L-C elements, called the L-C oscillators, are very popular for generating high frequency oscillations but t
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hey cannot be employed for generation of low frequency oscillations as they become too bulky and expensive. R- C oscil lators are commonly used for generating audio-frequencies as they provide good frequency stability and waveform. Also, with the advent of IC technology, R-C network is the only feasible solution, as it is very difficult to make a too high value inductance in an integrated circuit. Two com monly used R-C oscillators are (i) R-C phase shift oscillator and (ii) Wien bridge oscillator. Another commonly used audio-oscillator is the beat frequency oscillator (BFO). So these three audio-oscillators will be discussed here. For producing oscillations in an oscillator circuit we need positive feedback which means that the voltage signal feedback should be in phase with the input signal. For providing a positive feedback at one particular frequency, an inverting amplifier may be used with a feedback network that causes a phase shift of 180 ° at the desired frequency of oscillation, as shown in fig. (a). The 180 ° phase shift in the feedback signal can be obtained by a suitable network consisting of three R-C sections, as shown in fig. (b). When a phase-shift network such as that indicated in fig. is used in a phase shift oscillator, the R`s and C`s must be selected so as to produce a phase shift of 180 ° at the desired frequency of oscillation. The output of the voltage amplifier is fed to the input to the...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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