Sinusoidal voltage pulse

The commercial systems for zeta-potential determination using these electro-acoustic effects are typified by the AcoustoSizer 8000 (Matek Applied Sciences) consisting of five main components (Fig. 5). The synthesizer produces a continuous sinusoidal voltage which feeds into the gated amplifier. This creates a sinusoidal voltage pulse across the cell which contains the dispersion. The resulting ESA sound waves are... 

Figure 4.2 Pressure disturbance caused by a sinusoidal voltage pulse. Note that the two waves are 180° out of phase.

In the previous section we showed how a sinusoidal voltage pulse generates sinusoidal pulses of sound that appear to come from the electrodes. These ultrasound signals are measured in practice by attaching a pressure transducer to the material behind one of the electrodes. Two parameters can be obtained from this measurement the amplitude of the sound wave and the phase of the wave relative to the applied sinusoidal voltage. 

Active query methods measure cell impedance, which is then correlated to SoC. The technique often superimposes an active signal (a low amplitude, characteristic high-frequency square or sinusoidal current pulse) onto the battery and then uses a transfer function on the response waveform to determine the ohmic polarization or a direct correlation to SoC. One permutation of this technique uses the voltage response to indigenous current spikes to map impedance in a similar way. This method provides reasonable results, but if hardware is involved it is often complex and expensive even sensors will require a relatively high-speed data acquisition bus to minimize the slew between voltage and current. 

The power converter design will rely on Caterpillar s experience with state-of-the-art solid-state power converters that employ switches, inverters and pulse width modulation to shape a sinusoidal voltage and current in time with the existing power source on site. 

The oscilloscope is an instrument that permits the study of rapidly changing phenomena, such as a sinusoidal voltage or the pulse of a counter. The phenomenon is observed on a fluorescent screen as shown in Fig. 1.10. The horizontal axis of the screen measures time. The vertical axis gives volts. 

Pulse-Width-Modulated (PWM) Wave Inverter - A type of power inverter that produce a high quality (nearly sinusoidal) voltage, at minimum current harmonics. 

Geddes et al. (1975a) measured the current/voltage characteristics with a 5 ms duration heavily damped sinusoidal defibrillator pulse. Standard defibrillator electrodes 3.5" in diameter (60 cm ) were used with current pulses up to 80 A. The electrodes were face-to-face at 1 cm distance with the space filled with a 8.4 Q-cm electrode paste. It was found that the impedance of both electrodes (defined as the ratio of peak voltage to peak current) at such current levels was only a fraction of 1 Q. With the usual thorax tissue impedance of about 50 Q, little energy therefore is lost in electrode polarization processes. The 0.01 Hz impedance of the same electrode pair with small linear AC current levels was found to be about 2 kQ. This shows the extreme degree of nonlinearity. 

As can be seen from equation 10.3, a square wave exceeds the limits on the third harmonic by a factor of over 6, as well as others. So, how can a purer sinusoidal voltage and current waveform be generated Two approaches are used, pulse-width modulation and the more modem tolerance-band pulse-inverter technique. 

For reversible systems there is no special reason to use these techniques, unless the concentration of the electrochemical active species is too low to allow application of DCP or cyclic voltammetry. For a reversible electrochemical system, the peak potentials in alternating current voltammetry (superimposed sinusoidal voltage perturbation) and in square-wave voltammetry will be equal to the formal potential, i.e., JBp = E However, in differential pulse voltammetry, there is a systematic deviation according to ... 

Fig. 12 shows a push-pull based DC/AC converter (Jin and Enjeti, 2004), which consists of a front-end boost converter to regulate the DC voltage. A battery is connected to the intermediate DC bus to provide fast dynamic response during load-transients. The push-pull converter operates with a 50% duty ratio and provides rectangular voltage pulses at the secondary of the high-frequency transformer. The cycloconverter is sinusoidally modulated to produce a 60 Hz line-frequency voltage at the output. The push-pull converter... 

Static inverters are used to convert DC voltage into AC voltage. The simplest forms of inverters prodnce an output waveform that is rectangular, as a result of the simple switching process described in snb-section 15.4.1. A rectangular waveform can be used to feed some types of AC equipment e.g. incandescent lamps, domestic equipment such as kitchen mixers and kettles. Equipment that contains electronic devices may not function properly if their supply waveform is non-sinusoidal. Their timing circuits and pulse generating systems may be disturbed by the shape of the waveform or its derivative. 

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