You may be familiar with this effect. You switch audio equipment such as an amplifier to a different input and there is a loud click or `thump` in the speaker system. Not all equipment is affected. Some high end audio systems never suffer, but intercoms switching systems are often affected. Most audio outputs have some standing DC voltage which is separated by a capacitor. The capacitor will block this DC voltage while allowing the AC or audio to pass. Audio components using transformer coupling are not affected. The input to an amplifier may have a capacitive input or just a volume control. When switching inputs, charge is transferred through the switch as the input or output capacitors or both reach a state of equilibrium.
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This takes only a fraction of a second and what you hear is the annoying dc thump. A typical circuit for audio switching is shown below. This is just an example. At input 1, there is a standing dc voltage on the emitter of the transistor in system A. Thi
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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....
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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....
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