A valve radio receiver in its crudest form is a frequency determining tuned circuit, (consisting of an inductor and capacitor in parallel) followed by a series of valves coupled together. These valves act on the signal and provide high frequency amplification, detection (rectification) and low frequency amplification (audio amplification). A louds
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peaker or headphones terminates the line of valves. There are several ways in which linkage can be provided between the separate valves; the basic methods will now be shown. This arrangement is shown in Figure 3a. There is a resistor (Ra) between Valve A`s anode and the H. T supply. The A. C signal on the anode of valve A is passed to valve B via capacitor C, which should be well able to withstand the H. T supply voltage. In the event of a breakdown of this component, the grid of Valve B would be exposed to damaging H. T voltage from Valve A`s anode. Resistor Rb is to provide a path for electrons from the grid of valve B (the so-called grid leak resistor). The capacitance value of C is chosen to present low impedance to the signal to be processed. Resistance - Capacitance coupling is only suitable for use at audio frequencies (20Hz-20 KHz); above these frequencies capacitive effects in the valve reduces the gain possible from the coupled stages. This arrangement follows the form of the capacitive-resistive coupling illustrated in diagram 3a but the resistor between the first valve`s anode and the H. T voltage is replaced by an inductor (choke). The inductor and Capacitor values will depend on the frequency that the stage is required to operate at and the impedance of Valve B`s input circuit. This is arrangement is shown in figure 3b. It requires the use of a transformer (TR1) that is able to withstand the anode current from...
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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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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