Ads
related to: transistor amplifier
Search results
Results From The WOW.Com Content Network
The first discrete-transistor audio amplifiers barely supplied a few hundred milliwatts, but power and audio fidelity gradually increased as better transistors became available and amplifier architecture evolved. [93] Modern transistor audio amplifiers of up to a few hundred watts are common and relatively inexpensive.
The "PNP point-contact germanium transistor" operated as a speech amplifier with a power gain of 18 in that trial. In 1956 John Bardeen , Walter Houser Brattain , and William Bradford Shockley were honored with the Nobel Prize in Physics "for their researches on semiconductors and their discovery of the transistor effect".
Common-emitter amplifiers give the amplifier an inverted output and can have a very high gain that may vary widely from one transistor to the next. The gain is a strong function of both temperature and bias current, and so the actual gain is somewhat unpredictable.
The active device can be a vacuum tube, discrete solid state component, such as a single transistor, or part of an integrated circuit, as in an op-amp. [citation needed] Transistor amplifiers (or solid state amplifiers) are the most common type of amplifier in use today. A transistor is used as the active element.
The common collector amplifier's low output impedance allows a source with a large output impedance to drive a small load impedance without changing its voltage. Thus this circuit finds applications as a voltage buffer. In other words, the circuit has current gain (which depends largely on the h FE of the transistor) instead of voltage gain. A ...
Block diagram of a basic class-D amplifier. Note: For clarity, signal periods are not shown to scale. A class-D amplifier or switching amplifier is an electronic amplifier in which the amplifying devices (transistors, usually MOSFETs) operate as electronic switches, and not as linear gain devices as in other amplifiers.
Audio power amplifiers based on transistors became practical with the wide availability of inexpensive transistors in the late 1960s. Since the 1970s, most modern audio amplifiers are based on solid-state transistors, especially the bipolar junction transistor (BJT) and the metal–oxide–semiconductor field-effect transistor (MOSFET).
The only terminal remaining is the source. This is a common-source FET circuit. The analogous bipolar junction transistor circuit may be viewed as a transconductance amplifier or as a voltage amplifier. (See classification of amplifiers). As a transconductance amplifier, the input voltage is seen as modulating the current going to the load.