Precision rectifier

About: Precision rectifier is a research topic. Over the lifetime, 4952 publications have been published within this topic receiving 63668 citations. The topic is also known as: super diode.

Evaluation of SiC MOSFETs for a high efficiency three-phase buck rectifier

Abstract: This paper presents the characteristics of a 1200 V, 33 A SiC MOSFET and a 1200 V, 60 A SiC schottky barrier diode (SBD). The switching characteristics of the devices are tested by a double pulse test (DPT) based on a current-source structure at voltage levels up to 680 V and current up to 20 A. In addition, based on these devices, a 7.5 kW, three-phase buck rectifier for a 400 V dc architecture data center power supply is designed. The total loss of this rectifier is calculated full load. The results show that the SiC based buck rectifier can obtain low power loss and smaller weight and volume than a Si based rectifier.

Ac-dc converter and compressor driving apparatus and air conditioning apparatus using the same

Abstract: An AC-DC converter is provided which suppresses a harmonic current and improves power factor at low cost. Such an AC-DC converter includes a rectifier connected to an AC power supply via a reactor, capacitors connected in series across the output terminals of the rectifier, a first bidirectional switch having one end connected to one input terminal of the rectifier and the other end connected to a connecting point of capacitors, a second bidirectional switch having one end connected to the other input terminal of the rectifier and the other end connected to the other end of the first bidirectional switch, and a control circuit for actuating the first and second bidirectional switches during a half cycle of the AC power supply so as to control a voltage inputted to the rectifier to a desired output voltage.

Diversity signal strength indicator and site selection apparatus for using same

Abstract: A diversity signal strength indicator for transmission site selection in a cellular-like mobile radio system produces an output strength indication signal which is proportional to the logarithm of the average strength of two diversity input signals. The two input diversity signals are time multiplexed together to form a composite signal, and a log amplifier/envelope detector then produces an intermediate log signal which is proportional to the logarithm of the envelope of the composite signal. The intermediate log signal is then operated on by a peak detector to produce a peak intermediate log signal which is then passed through a low pass filter to produce an output strength detection signal proportional to the average of the intermediate log signal and thus proportional to the logarithm of the average strength of the diversity input signal. The peak detector is preferably comprised of a capacitor charged through a diode for storing the peak levels of the intermediate log signal and a current source for draining the charge on the capacitor at a substantially uniform rate which is independent of the magnitude of the peak signal which is stored during time periods between peak signals. In another embodiment, the time multiplexed composite signal is first detected and then passed through a squaring circuit, a low pass filter and then a log amplifier to produce an output indicator circuit proportional to the logarithm of the average strength of the input diversity signals. The diversity signal strength indicator is employed in combination with a site selection system for selecting suitable ones of a plurality of transceiver sites for actuation and reception of signals to be transmitted to a remote portable unit.

Voltage regulator for variable speed permanent magnet alternators

Abstract: A voltage regulating system for a permanent magnet alternating current generator that has a rotor and a three phase Y-connected output winding. The system has first and second three phase full wave bridge rectifiers each comprised of a plurality of controlled rectifiers. The ends of the phase windings of the output winding are connected to the AC input terminals of the first bridge rectifier. The phase windings are connected to taps and these taps are located between the neutral and the ends of the phase windings. The taps are connected to the AC input terminals of the second bridge rectifier. The first bridge rectifier is enabled and the second bridge rectifier is disabled at speeds of rotation of the rotor below a predetermined speed. At rotor speeds above the predetermined speed, the first bridge rectifier is disabled and the second bridge rectifier is enabled.

Time-reversal duality of high-efficiency RF power amplifiers

Abstract: The similarity between RF power amplifiers and rectifiers is discussed. It is shown that the same high-efficiency harmonically-terminated power amplifier can be operated in a dual rectifier mode. Nonlinear simulations with a GaN HEMT transistor model show the time-reversal intrinsic voltage and current waveform relationship between a class-F amplifier and rectifier. Measurements on a class-F-1 amplifier and rectifier at 2.14 GHz demonstrate over 80% efficiency in both cases.