This circuit produces a pure, - 80-dB THD sine wave with a frequency that is equal to the fc of IC3`s filter. A TT
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L counter, an 8-channel analog multiplexer, and a fourth-order low-pass filter can generate 1- to 25-kHz sine waves with a THD of better than - 80 dB. The circuit cascades the two second-order, continuous-time Sallen-Key filters within IC3 to implement the fourth-order low-pass filter. Two resistive dividers connected from ground to VDD and ground to Vss provide bipolar dc inputs to the multiplexer. lb operate the circuit, you first must choose the filter"s cutoff frequency, fc, by tying IC3"s D0 through D6 inputs to 5 V or ground. The cutoff frequency can be at 128 possible levels between 1 and 25 kHz, depending on those 7 digital input levels. Because this figure ties Z)0 through D6 to ground, fc equals 1 kHz. The 100-kHz potentiometer adjusts the output level anywhere from 1.5 V below Vdd to 1.5 V above Vss-The clock input frequency must be 8 times higher than the filter"s fc. The multiplexer then produces an 8x oversampled staircase approximation of a sine wave. 8 oversampling greatly simplifies the smoothing requirements of the low-pass filter by pushing the first significant harmonic out to 7 the fundamental. All higher-order harmonics are removed by IC3, which includes an uncommitted amplifier for setting the output level.
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....
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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....
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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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