The time constant of R1C1 determines the low-cutoff frequency while the time constant of R2C2 determines the high cutoff frequency. The pass-band gain, Avpass=R2/R1. For a low-cut filter, that is a high-pass filter, Za must be capacitors and Zb resistors. By substituting Za=1/sC and Zb=R into above equation, the following equation is obtained: For
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a high-cut filter, that is a low-pass filter, Za must be resistors and Zb capacitors. By substituting Za=R and Zb=1/sC into above equation, the following equation is obtained: The best choice for the Q-factor is 0. 707. This results in the sharpest curve, without any overshoot. If this Q-factor is selected, the value of K must be 1. 586. Note that this is also the pass-band gain. The signal should therefore be attenuated if constant signal level is desired. If a slope steeper than 12db/oct is desired, a higher order filter can be used. It is best to use the Butterworth response for audio, because of its flat response. The simplest type of equaliser is the low and high shelving equalisers. This is usually called Bass and Treble on Hi-fi sets. Figure 3 shows the basic topology for such an equaliser. The potentiometer, Rp, sets the boost cut ratio. The impedance of Z(s) must be high at the frequencies to boost/cut and low at other frequencies, effectively shorting out Rp. If a capacitor is substituted for Z(s), a low shelving equaliser is realised, while an inductor is needed for a high shelving equaliser. Figure 4 shows a circuit for a combined Lo and Hi shelving equaliser as used in conventional hi-fi sets and mixing consoles. As can be seen, the inductor in parallel with Rtreble is omitted, C2 is instead inserted. At the high frequencies, Rbass is shorted out by C1. The higher the frequency becomes, the lower C2 s...
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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