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Alternating Current (ac) Electronics
Published in Dale R. Patrick, Stephen W. Fardo, Electricity and Electronics Fundamentals, 2020
Dale R. Patrick, Stephen W. Fardo
Figure 2-3 shows several voltage values associated with ac. Among these are peak positive, peak negative, and peak-to-peak ac values. Peak positive is the maximum positive voltage reached during a cycle of ac. Peak negative is the maximum negative voltage reached. Peak-to-peak is the voltage value from peak positive to peak negative. These values are important to know when working with radio and television amplifier circuits. For example, the most important ac value is called the effective, or measured, value. This value is less than the peak positive value. A common ac voltage is 120 V, which is used in homes. This is an effective value voltage. Its peak value is about 170 V. Effective value of ac is defined as the ac voltage that will do the same amount of work as a dc voltage of the same value. For instance, in the circuit of Figure 2-4, if the switch is placed in position 2, a 10-V ac effective value is applied to the lamp. The lamp should produce the same amount of brightness with a 10-V ac effective value as with 10 V dc applied. When ac voltage is measured with a meter, the reading indicated is effective value.
Regression
Published in Michael Baron, Probability and Statistics for Computer Scientists, 2019
The interceptinterceptβ0=G(0) equals the value of the regression function for x = 0. Sometimes it has no physical meaning. For example, nobody will try to predict the value of a computer with 0 random access memory (RAM), and nobody will consider the Federal reserve rate in year 0. In other cases, intercept is quite important. For example, according to the Ohm's LawOhm's Law (V = R I) the voltage across an ideal conductor is proportional to the current. A non-zero intercept (V = V0 + R I) would show that the circuit is not ideal, and there is an external loss of voltage.
Electrical safety
Published in Phil Hughes, Ed Ferrett, Introduction to Health and Safety in Construction, 2015
Electric shock is the convulsive reaction by the human body to the flow of electric current through it. This sense of shock is accompanied by pain and, in more severe cases, by burning. The shock can be produced by low voltages, high voltages or lightning. Most incidents of electric shock occur when the person becomes the route to earth for a live conductor. The effect of electric shock and the resultant severity of injury depend upon the size of the electric current passing through the body which, in turn, depends on the voltage and the electrical resistance of the skin and body. If a person comes into contact with a voltage above about 50 volts, they can receive a range of injuries, including those directly resulting from electrical shock (such as problems with breathing and heart function), and indirect effects resulting from loss of control (such as falling from height or coming into contact with moving machinery). The chance of being injured by an electric shock increases where it is damp or where there is a lot of metalwork.
Deep brain stimulation programming strategies: segmented leads, independent current sources, and future technology
Published in Expert Review of Medical Devices, 2021
Bhavana Patel, Shannon Chiu, Joshua K. Wong, Addie Patterson, Wissam Deeb, Matthew Burns, Pamela Zeilman, Aparna Wagle-Shukla, Leonardo Almeida, Michael S. Okun, Adolfo Ramirez-Zamora
A DBS system involves 1) an electrode that is placed into a brain target (gray matter, white matter, or an interface), 2) an implantable pulse generator (IPG) which includes a battery and electronic circuit used to generate the electrical field, and, 3) an extension cable connecting the electrode to the IPG [56]. Depending on the DBS system, the electrical source can be voltage- or current-driven. Most recently approved devices have been built for constant current stimulation since the traditional constant voltage DBS systems are vulnerable to impedance changes and uneven electrical distribution across tissues. By Ohm’s law (V ≈ I.Z), voltage (V) is directly proportional to impedance (Z) and current (I). Hence, in a constant-voltage system, an increase in impedance will result in a decrease in current and a reduction in stimulation delivered.
To Design an off Gird PV System for un electrified area of District Tharparkar, Pakistan
Published in International Journal of Green Energy, 2021
Kamlesh Kumar, Mahesh Kumar, Amir Mahmood Soomro
Assumptions taken for design: Inverter converts DC into AC power with efficiency of about 90%.Battery voltage used for operation = 12 volts.The combined efficiency of inverter and battery will be calculated as: combined efficiency = inverter efficiency × battery efficiency = 0.9 × 0.9 = 0.81 = 81%.Sunlight available in a day = 8 hours/day (equivalent of peak radiation.PV panel power rating = 40 Wp (Wp, meaning, watt (peak), gives only peak power output of a PV panel) A factor called „ operating factor‟ is used to estimate the actual output from a PV module. [The operating factor between 0.60 and 0.90 (implying the output power is 60 to 80% lower than rated output power) in normal operating conditions, depending on temperature, dust on module, etc.]
Electrical resistive heating characterization of conductive hybrid staple spun yarns
Published in The Journal of The Textile Institute, 2020
Amir Shahzad, Abdul Jabbar, Muhammad Irfan, Muhammad Bilal Qadir, Zuhaib Ahmad
Electric heating effect in an electric heating element is resulted due to release of electric energy in the form of heat up to some extent depending on the resistance of the electric circuit and electric current flowing through it. Greater the resistance of conductor or current flowing through it, higher will be the heating effect called electric current heating effect. According to Joule’s equation (H = I2Rt), the heat generation in any conductive material is directly proportional to square of current, linear resistance and the time for which the current is passed from the resistive heating element. While at fixed resistance of conductor, the current “I” is function of voltage applied according to the Ohm’s law (V = IR). Since conversion of electrical energy into heat energy per unit time, called power, is determined as P = I2R. It means that if the resistance of material is lower, it will allow the material to pass more current and in the case of higher resistance, this factor will resist more electric charges to pass through the electrical heating element producing more heat.