Isolation transformer

About: Isolation transformer is a research topic. Over the lifetime, 8145 publications have been published within this topic receiving 72396 citations.

Inverter circuit including transformer with shielding of undesired radiations

Abstract: A transformer with an electrostatic shield body between its primary and secondary windings, one end of the shield body being connected to a zero potential point of the primary side from the AC standpoint. This reduces the capacity coupling between the primary and secondary windings. This transformer is particularly useful with an inverter. The transformer may include primary and secondary windings, each having a pair of terminals, and a magnetic core provided in connection with the primary and secondary windings magnetically. First and second static shield bodies may be provided at each side of the primary and secondary windings and therebetween, and these first and second static shield bodies are electrically connected to one terminal of the primary and secondary windings, respectively, so as to reduce the capacitance therebetween.

High voltage discharge lamp apparatus for vehicles

Abstract: A discharge lamp apparatus is provided having a DC power source (1) and a high voltage discharge lamp (2) comprising: a DC-DC converter comprising a transformer (41) for boosting a voltage supplied from the DC power source, a switching element (42) connected to a primary winding (41a) of the transformer in series, and a capacitor (45) connected in parallel with the transformer connected in series with the switching element, for generating the boosted voltage; a starter circuit (7) having a thyristor (76) for turning on the thyristor when the high voltage discharge lamp is started to light and for applying a high voltage pulse to the high voltage discharge lamp based on the boosted voltage generated from the DC-DC converter; and a gate circuit (11) for generating the gate signal to turn on the thyristor, wherein the switching element and the gate circuit are both formed on a hybrid IC board (100), the negative electrode side terminal of the capacitor is connected to a first wiring member (24) and then connected to the hybrid IC board by way of the first terminal (12c), wherein the cathode terminal of the thyristor is connected to a second wiring member (24) and then connected to the hybrid IC board by way of the second terminal (12m) different from the first terminal, and wherein the first terminal and the second terminal are electrically connected on the hybrid IC board.

Experimental study of shoot-through control methods for qZSI-based DC/DC converters

Abstract: This paper proposes a novel step-up DC/DC converter with galvanic isolation – the quasi-Z-source inverter (qZSI) based DC/DC converter and discusses three different shoot-through PWM control methods suitable for this topology. The proposed converter is meant for applications where the wide range of voltage gain is demanded, e.g. with renewable energy sources (fuel cells, photovoltaic cells), in telecom, aerospace and some other applications. For the verification of theoretical assumptions the converter prototype was assembled and tested. Experimental waveforms of the converter operated with different shoot-through PWM control methods are compared and discussed. Design considerations for converter and different control signal generators are provided.

DC and AC current sensor having a minor-loop operated current transformer

Abstract: The invention relates to a current sensor for non-contacting measurement of current in a line. Current is sensed by a circuit which provides a high frequency reversing voltage to a sensing winding on a current transformer, for driving the transformer into its linear region at least once per high frequency cycle. Current through the sensing winding is sampled while the transformer is in that linear region. Preferably, the current is sampled approximately at the instants of reversal of the voltage being applied to the sensing winding, and the sample having the lower absolute value is selected as a sample proportional to the line current.

PCB based transformer for power MOSFET drive

Abstract: Power MOSFET and IGBT gate drives often face isolation and high voltage constraints. The gate drive described uses a printed circuit board based transformer combined with the memory effect of the power MOSFET input capacitance. This transformer is a bidirectional link between the ground referred control IC and the floating gate drive. It transfers energy and signal to the gate drive, provides full duty cycle range, perfect dV/dt immunity and virtually no voltage constraint. No floating auxiliary is required for the secondary circuit. If the short circuit protection is operated, an alarm signal is transmitted back to the primary through the same transformer. This circuit is perfectly suited to drive floating and/or isolated switches in motor drives, uninterruptible power supplies and AC switches. Due to the printed winding approach, cost reduction can be expected in the transformer manufacture automation. >