Electrode voltage and iv bias voltage quantumwise

Power output stages are described in Amplifiers Module 5. This section describes some types of current and voltage amplifier circuits commonly used to modify input and output impedances. Therefore the output stage of an amplifier may need to have a low output impedance, much lower than would be possible using the common emitter voltage amplifiers described in Amplifiers Module 4.1 to 4.3. Any or all of these transducers may have quite low impedances and require considerable amounts of signal current or power, rather than large signal voltages to operate them. A radio frequency (RF) amplifier in a transmitter may be used to drive an antenna (aerial), or a DC amplifier may be driving an electric motor or a relay. For example the electrical waves produced by an audio amplifier will be converted into sound (air pressure) waves by a loudspeaker. The final (output) stage in a multi-stage amplifier has to drive a вЂtransducerвЂ™, which will convert the electrical signal energy produced by the amplifier into some other useful form. Where audio amplifier inputs may have to cater for a number of different input sources, switch selectable inputs to compensate for specific input devices, as described in Amplifiers Module 4.1. can have impedances ranging from a few hundred ohms to several thousand ohms. This section looks at practical methods of obtaining suitable input and output impedances where amplifiers interface with typical input and output devices such as microphones and loudspeakers.ДЄudio input sources, such as microphones, pick-ups, radio tuners etc. AC Theory Module 7.2 describes how correct matching reduces signal loss between the output of one amplifier and the input of the next in multi stage amplifiers.

The input and output impedances of an amplifier are very important parameters that affect the overall gain in multi-stage amplifiers.

Electrode voltage and iv bias voltage quantumwise