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DC Circuit Analysis and Basic Electronic Devices
Published in S. Bobby Rauf, Electrical Engineering for Non-Electrical Engineers, 2021
A diode can be viewed as a device that functions as an electronic “check valve.” As we know, the function of a check valve, in mechanical or hydraulic systems, is to permit the flow of fluids in one specific direction. In other words, an attempt by the fluid to move in the reverse direction is blocked by a check valve. A diode performs the same function in the flow of current. A diode permits the flow of current only from a higher voltage (or electrical potential) point in an electrical circuit to a lower voltage or ground potential point. This unidirectional behavior is called rectification, and this function of a diode finds a common application in the conversion of alternating current (AC) to direct current (DC). Common application of diodes in rectifiers and other equipment are discussed later in this chapter.
DC Circuit Analysis, Diodes, and Transistors – BJT, MOSFET, and IGBT
Published in S. Bobby Rauf, Electrical Engineering Fundamentals, 2020
A diode can be viewed as a device that functions as an electronic “check valve.” As we know, the function of a check valve, in mechanical or hydraulic systems, is to permit the flow of fluids in one specific direction. In other words, an attempt by the fluid to move in the reverse direction is blocked by a check valve. A diode performs the same function in the flow of current. A diode permits the flow of current only from a higher voltage (or electrical potential) point in an electrical circuit to a lower voltage or ground potential point. This unidirectional behavior is called rectification, and this function of a diode finds a common application in the conversion of AC to DC. Common applications of diodes in rectifiers and other equipment are discussed later in this chapter.
Electrical Field in Materials
Published in Ahmad Shahid Khan, Saurabh Kumar Mukerji, Electromagnetic Fields, 2020
Ahmad Shahid Khan, Saurabh Kumar Mukerji
The word “capacitor” or “condenser” is frequently used by a commoner in connection with the domestic electrical appliances. A capacitor is a device that introduces capacitance in an electrical circuit. A capacitor opposes the instantaneous change of voltage. It comprises two parallel surfaces whereupon the charges of opposite polarity accumulate. It stores energy in electric field during charging by a battery which is analogous to filling of the air (or water) tank. The charging (or discharging on removal of source) of the capacitor depends on the time constant of the circuit, (τ = R·C). The surfaces of the capacitor may be in the form of two parallel flat plates, two concentric cylinders or spheres, etc. These surfaces are separated by some dielectric material or simply by air.
Broadband vibration suppression of graded/disorder piezoelectric metamaterials
Published in Mechanics of Advanced Materials and Structures, 2023
Yijie Liu, Chunyu Han, Dongying Liu
Considering a piezoelectric metamaterial beam with rectangular cross-section, as shown in Figure 1(a). The piezoelectric sheets are periodically attached to the bottom and top surfaces of the host beam. The electrodes over the piezoelectric sheet connect with the external electrical circuit, which selects a circuit network formed by one resistance, one inductance, one artificial capacitance (negative capacitance) in series, as shown in Figure 1(b). Besides, the geometrical and material properties of this meta beam are given in Table. 1 and Table. 2. The complex impedance of the electric circuit is represented as Z. The sandwiched beam and the piezo patch have the same width wb in Figure 1(c). a and hb denote the unit length and thickness of the host beam. The length and thickness of the piezo sheet are lp and hp, respectively. Controlling the shunted piezoelectric circuit can adjust the impedance difference between the piezoelectric patch and the substrate, thereby realizing the tunable attenuation zone in the meta structure. This paper mainly considers the attenuate properties of flexural elastic waves in the piezoelectric metamaterial beam.
Effect of electromagnetic energy harvesting technology on safety and low power generation in sustainable transportation: a feasibility study
Published in International Journal of Sustainable Engineering, 2020
Mohammadreza Gholikhani, Mohammadali Sharzehee, Seyed Amid Tahami, Frances Martinez, Samer Dessouky, Lubinda F. Walubita
The experimental tests were conducted to evaluate the potential of the prototype ESE for generating electrical power and the effects of varying the load magnitudes, stiffness of the compression springs, and time of loading and unloading. Due to different vehicles’ weights, different vertical loads (3, 5, and 10 kN) in Harvesine waveform were applied to simulate the wheel loading. Loading times and unloading times were chosen to reflect vehicles speed in approaching and leaving the speed bump. Therefore, four loading cycles and six unloading times were arbitrarily selected. Table 1 shows the test variables including the loading, spring stiffness, loading times, unloading times, and the load waveform (Haversine). In addition, two sets of springs with two stiffness magnitudes – 20,472 and 13,485 N/m – were used to meet the aforementioned criteria of the T-plate movements. The generator was connected to the external resistor to make a closed electrical circuit. All the laboratory tests were conducted at room temperature (~25 C°).
An arbitrary-order differentiator design paradigm with adaptive gains
Published in International Journal of Control, 2018
Markus Reichhartinger, Sarah Spurgeon
where xb, xv and i represent the distance between ball and coil (see Figure 6(b)), the velocity of the ball and the electric current, respectively. The electrical circuit consists of an ideal resistor (with resistance R), the coil (with inductance L0) and a voltage source representing the system's input u. The acceleration of gravity is denoted by g, the mass of the ball is labelled as m and c is a positive constant related to the force acting on the ball due to the magnetic field.3The laboratory setup used in this paper provides measurements of the ball position xb and the current i. The parameters of the laboratory setup are listed in Table 2.