ABSTRACT
Signal processing is accomplished by microelectronic circuits and devices. Transducers convert time-varying physical quantities into electrical signals. Transistors are three- or four-terminal semiconductor devices. In power electronic circuits, bipolar junction (BJT), metal-oxide semiconductor field-effect (MOSFET), and insulated-gate bipolar (IGBT) transistors are used. The basic circuit elements (diodes, transistors, and thyristors) should be considered when studying power converters used in electromechanical and micro-electromechanical systems. The simplest fundamental circuit element is the diode, which is a two-terminal device with positive and negative terminals, called anode and cathode, respectively. The basic dc-dc power converters used in electromechanical systems are switching converters. Mathematical models in the form of nonlinear differential equations for power converters can be developed using the Kirchhoff laws or Lagrange equations of motion. The signal-level transducer output must be amplified, and operational amplifiers are used to perform amplification. Power amplifiers allow one to perform amplification, and various classes of amplifiers are available.
