A tone generator that runs on as little as 1. 5 Vdc, using the Sallen-Key configuration. And finally, I`ll apply the tone generator to implement a phantom powered signal source for testing balanced microphone inputs. Textbooks and web pages usually show the Wien Bridge configuration when describing single-opamp audio oscillators. The Wien Bridge circuit shown in sketch form below will oscillate at a
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frequency equal to 1/(2 Oscillation will be self-starting when overall gain is greater than 3, so we want (R3/R4 + 1) > 3, or R3/R4 > 2. Once oscillation begins, additional circuit elements must be brought into play to maintain a constant output level with low harmonic distortion. Tuning this kind of oscillator is complicated by the fact that the amount of gain required to maintain stable oscillation depends on how closely the tuning resistors and capacitors are matched. This is why the output level of an RC (resistance-capacitance) oscillator bounces around so much when setting the frequency. If you need a tunable single-opamp RC oscillator, then you need to take special care to be sure that R`s and C`s remain equal as they are varied. Here I`ll diverge from standard practice and introduce a new circuit for RC oscillators. Based on the Sallen-Key equal-component-value second-order LP (low-pass) filter, my new circuit is nothing more than an LP filter with the input grounded. Because it is second-order, this circuit has the capacity for sustained oscillation built in, which designers normally try to avoid. Frequency is the same as for the Wien Bridge oscillator, which is 1/(2 RC) where R = R1 = R2, and C = C1 = C2. The condition for oscillation is also the same as for the Wien Bridge configuration, which is an overall gain greater than 3. Actually, most operating parameters of this new circuit are similar to the Wien Bridge...
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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