Everyone is familiar with the sound of a wah pedal. This is a resonant peak in the signal that can get moved around. Not so familiar is a notch, or a sudden reduction in level at one frequency. Sometimes a notch can be very useful in getting a specific sound. Even better would be if you could get either a peak or a notch, depending on how you set the controls - something like the
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frequency response diagram. The diagram shows the possible frequency responses of a variable Q peak/notch filter. "Wait a minute! What`s Q " I hear you ask. The techie explanation is that Q is the energy stored divided by the energy dissipated per cycle in a network. Let me translate that into something more useful. A guitar string will vibrate a long time if plucked. The initial pluck that sets it into motion stores a chunk of energy in the string that is saved by the interchange of motion for string stretch on every vibration. It dissipates very little of its energy per cycle, so it stays in motion a long time - it`s a high Q mechanical filter. If you put your finger on the string, it stops ringing very quickly because your finger damps it, removing a lot of energy as the string moves. Your finger has lowered the Q of the vibrating string, removing a lot of energy from it each vibration, so it stops vibrating quickly. Q is also a measurement of bandwidth. Another engineer`s measurement of Q is to divide the center frequency of the filter`s response by the difference between the frequencies where the response is 1/2 of the center response. Q is kind of a measurement of resonance, then. A moderately resonant filter is like a wah pedal - There is a peak of frequency response at the resonant frequency of the wah. To give you an idea about how Q relates to sound, most wahs have a Q of about 2-10. Q is also related to...
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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