The South African Sugar Association Experiment Station, Agricultural Engineering Department conducted a series of semi-mechanised versus fully mechanised harvesting trials on a large commercial estate in Swaziland over the 1998/1999, 2000/2001 and 2001/2002 seasons. During the trials machinery performance was measured, differences in the quality of cane delivered to the factory were determined,...

To improve the performance of motor drives, there is a need to improve the quality and reliability of the drive system. With the high power handling capability of the switching device, pulse width modulated AC chopper can be used in high power applications. AC chopper using pulse width modulation provides substantial advantages over conventional line commutated AC controllers. To alleviate the ...

Abstract: A low-power and low-noise dynamic instrumentation amplifier (IA) for biopotential acquisition is presented. A dynamic IA that can reduce power consumption with a timely piecewise power-gating method, and noise level with an alternating input and chopper stabilization technique is fabricated with a 0.13-μm CMOS. Using the reconfigurable architecture of the IA, various combinations of t...

FIGURE 2. Traditional X-ray scattering experiment setup. Photo Credit: Argonne National Laboratory. In addition to the setup shown in Figure 2, time resolution at BioCARS is provided by precise synchronization of additional beam blocking equipment placed before the sample under test—two rotating disk choppers and a shutter [2]. The X-ray beam is intercepted by a watercooled heat load chopper wh...

A combination of rectifier and DC – DC chopper is useful in feeding DC loads where the DC input to the loads needs to be stepped up or down. Both rectifier and chopper are based on power electronic switches which inject harmonics in the system. This harmonics is an undesirable effect which should be mitigated effectively. For this, passive harmonic filters are used. Passive harmonic filters are...

Various circuit technologies have been studied and developed. One of main streams concerns a soft switching technology to mitigate switching stress, leading to the reduction in switching losses or electro-magnetic noise. On the other hand, as a characterized orthodox technology, the existing chopper circuit is used for the electric vehicles, etc. Such technologies have a tendency to go out of v...

We describe a general offset-cancelling architecture for analog multiplication using chopper stabilization. Chopping is used to modulate the offset away the output signal where it can be easily filtered out, providing continuous offset reduction which is insensitive to drift. Both square wave chopping and chopping with orthogonal spreading codes are tested and shown to reduce the offset down to...

For a tone that is amplitude modulated by two tones (fmod1 and fmod2), neither the stimulus waveform nor the half-wave rectified waveform has spectral energy at the envelope beat frequency (fmod2-fmod1). The response of ventral cochlear nucleus units in the chinchilla were recorded for best frequency tones that were amplitude modulated by low-frequency, two-tone complexes. Fourier analysis of p...

Temporal encoding of stimulus features related to the pitch of iterated rippled noises was studied for single units in the chinchilla cochlear nucleus. Unlike other periodic complex sounds that produce pitch, iterated rippled noises have neither periodic waveforms nor highly modulated envelopes. Infinitely iterated rippled noise (IIRN) is generated when wideband noise (WBN) is delayed (tau), at...