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Showing posts with the label Class

Class Diagram

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Think of the many objects around you in the real world The majority of these objects will have attributes and behavoirs A class diagram consists of a number of these class representation connected by lines which show the relationship between the classes

Pure Class A Headphone Amplifier Circuit Schematic

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Description  This design is derived from the Portable Headphone Amplifier featuring an NPN/PNP compound pair emitter follower output stage. An improved output driving capability is gained by making this a push-pull Class-A arrangement. Output power can reach 427mW RMS into a 32 Ohm load at a fixed standing current of 100mA. The single voltage gain stage allows the easy implementation of a shunt-feedback circuitry giving excellent frequency stability.  Tilt control:   The mentioned shunt-feedback configuration also allows the easy addition of frequency dependent networks in order to obtain an useful, unobtrusive, switchable Tilt control (optional). When SW1 is set in the first position a gentle, shelving bass lift and treble cut is obtained. The central position of SW1 allows a flat frequency response, whereas the third position of this switch enables a shelving treble lift and bass cut. Circuit Diagram:  Parts P1 = 22K Dual gang Log Potentiometer (ready for Stereo) R...

Class C Power Amplifier

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If the amplifier class B need two transistors to work properly, then there are the so-called class C amplifier that only need 1 transistor. There are few applications that really only requires a positive phase only. An example is the pilot frequency detector and amplifier, RF tuner amplifier circuit and so forth. Class C transistor amplifier active work only on the positive phase only, even if the need is quite narrow only the peaks are strengthened. Time signal can replica by series resonance of L and C. Typical of the series class C amplifier is like in the following series. Basic Schematic Power Amplifier Class C The circuit is also not necessary created bias, because the transistor was deliberately made ​​to work the saturation region. Series L C in the circuit will resonate and contributed important in re-replicate input signal into an output signal with the same frequency. This series if given the bait...

18W Class B Audio Amplifier with Tone Controls

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18W Class-B Audio Amplifier with Tone Controls 18W Class-B Audio Amplifier with Tone Controls In order to satisfy repeated requests by correspondents, a medium power audio amplifier incorporating tone controls in the feedback path was finally designed. To avoid an excessive increase in parts-count, due to the addition of the tone controls, a simple amplifier circuitry was designed on the same guidelines of the successful 45 Watt Class B Amplifier, but using the excellent NE5534 IC instead of a discrete component op-amp to drive the output "dumper" transistors. The particular circuit configuration, allowed to push the NE5534 exceptional capacity of driving the output transistors near to its limits, enabling the whole amplifier to deliver relatively high power outputs without problems. For this reason, it was possible to obtain 18W into an 8 Ohm load using a power supply voltage of +/- 20V. Despite the complication added by the tone controls, the amplifier has an input sensitiv...

Class C Power Amplifier

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If the amplifier class B need two transistors to work properly, then there are the so-called class C amplifier that only need 1 transistor. There are few applications that really only requires a positive phase only. An example is the pilot frequency detector and amplifier, RF tuner amplifier circuit and so forth. Class C transistor amplifier active work only on the positive phase only, even if the need is quite narrow only the peaks are strengthened. Time signal can replica by series resonance of L and C. Typical of the series class C amplifier is like in the following series. Basic Schematic Power Amplifier Class C The circuit is also not necessary created bias, because the transistor was deliberately made ​​to work the saturation region. Series L C in the circuit will resonate and contributed important in re-replicate input signal into an output signal with the same frequency. This series if given the bait...