D.C.-d.c. converter with a transformer and a reactance coil

Details D.C.-d.c. converter with a transformer and a reactance coil D.C.-d.c. converter with a transformer and a reactance coil

2000-11-15

2001-11-27

Wong, Peter S. (Department: 2838)

Electricity: power supply or regulation systems

In shunt with source or load

Using choke and switch across source

C323S271000, C323S282000

Reexamination Certificate

active

06323627

ABSTRACT:

BACKGROUND INFORMATION
1. Field of the Invention
The present invention relates to a DC-DC converter having a transformer and a reactance coil and a controllable switch for turning the DC voltage supply on and off definition of the in claim
1
.
2. Background Information
To supply power to loads, DC-DC converters in various designs are used for many purposes, e.g., for supplying power to gas discharge lamps, in particular high pressure gas discharge lamps used in motor vehicles.
Thus, for example, flyback converters, flux converters and CuK converters may be used. In addition, quasi-resonant converters are discussed in “Quasi-Resonant Converters Topologies and Characteristics” by Kwang-Hwa Liu, Ramesh Oruganti and Fred Lee: IEEE Transactions on Power Electronics, vol. PE-2, no. 1, Jan. 1987.
SUMMARY OF THE INVENTION
An object of an exemplary embodiment of the present invention is to provide a DC-DC converter that provides a voltage transformer having a high efficiency at the lowest possible cost through circuit technology measures.
The DC-DC converter according to an exemplary embodiment of the present invention is believed to provide a considerable reduction in switching losses at what is believed to be very low cost in terms of the circuit technology. Another special advantage is the reduced EMP (electromagnetic pollution) and the associated phenomena and countermeasures.
According to an exemplary embodiment of the present invention, the in the DC-DC converter, which is designed as a constant-current transformer, is that the contact gap of a switching transistor is set at the reference potential at the connecting tap between the primary and secondary windings of the reactance coil which is connected as a transformer with a certain transformation ratio; the anode-cathode segment of a diode and an output condenser are arranged at the reference potential in series with the secondary winding of the reactance coil, where the output voltage for a load is supplied over the output capacitor; the input DC voltage is sent to the primary winding of the reactance coil via the reactance coil, and a capacitor is arranged in parallel with the contact gap of the switching transistor, thus creating with the inductance and the capacitance a series resonant circuit that is effective in the turn-on and turn-off phases of the switching transistor.
According to an other exemplary embodiment of the voltage transformer according to the present invention, the switching transistor is switched to conducting when the voltage applied to its conducting segment is approximately at a value of zero. In another exemplary embodiment, a circuit is provided that detects the voltage applied to the conducting segment of the switching transistor and detects its zero crossings. Through these measures, conducting state power losses and switching losses of the switching transistor are greatly reduced.
In an expedient refinement of this exemplary embodiment of the present invention, the switching transistor is a MOS-FET transistor.
According to another exemplary embodiment of the voltage transformer according to the present invention, which contributes toward a further reduction in cost, the reactance coil upstream from the primary winding is implemented as a discrete reactance coil or, with a suitable choice of the coupling factor, as the leakage inductance of the reactance coil.
According to another exemplary embodiment of the present invention, the capacitor to be connected parallel to the contact gap of the switching transistor can be implemented by a discrete capacitor or by the parasitic output capacitance of the component or by a combination of the two possible embodiments.
In another exemplary embodiment of the present invention, the MOS-FET transistor is controlled at the gate with a gate resonance control.
According to an exemplary embodiment of the present invention, a gate resonance control or controller is also made available in particular for controlling a DC-DC converter such as that provided by the measures according to the exemplary embodiment of the present invention, in which the gate resonance control includes a gate reactance coil upstream from the gate of a MOS-FET transistor which switches the DC supply voltage, where the gate reactance coil can be connected to a control voltage source over the cathode-anode segment of a first diode and a first transistor switch, but it can also be connected to reference potential over the anode-cathode segment of a second diode and a second transistor switch, where the parasitic gate-drain capacitance and the parasitic gate-source capacitance are used as capacitances for the resonant circuit, and the clock cycle of turning the two transistor switches on and off is selected so that the gate voltage escalates in the desired manner. In another embodiment of this gate resonance control, bipolar transistors are used as the transistor switches.


REFERENCES:
patent: 4720668 (1988-01-01), Lee
patent: 4841220 (1989-06-01), Tabisz et al.
patent: 4857822 (1989-08-01), Tabisz
patent: 4866367 (1989-09-01), Ridley
patent: 4931716 (1990-06-01), Jovanovich et al.
patent: 4977493 (1990-12-01), Smith
patent: 5343140 (1994-08-01), Gegner
patent: 5418704 (1995-05-01), Hua et al.
patent: 5543704 (1996-08-01), Thoren
patent: 5594629 (1997-01-01), Steigerwald
patent: 0 508 595 (1992-10-01), None
Liu K-H, Oruganti, R, Lee F C Y: “Quasi-Resonant Converters—Topologies and Characteristics” IEEE Trans. Power Electron, vol. PE-2, No. 1, Jan. 1987, pp. 62-71.

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