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

• US 6,323,627 B1
• Filed: 11/15/2000
• Issued: 11/27/2001
• Est. Priority Date: 02/28/1998
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Schmiederer, Claus, Kern, Robert
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): Vu, Bao Q.
• Application Number:
  US09/623,112
• Time in Patent Office: 377 Days
• Field of Search: 323/222, 323/235, 323/271, 323/282
• US Class Current: 323/222
• CPC Class Codes: H02M 3/155 using semiconductor devices only
• CPC Class Codes: H05B 41/2882 the control resulting from an action on the static converter
• CPC Class Codes: H05B 41/2885 Static converters especially adapted therefor; Control thereof H05B41/2882 takes precedence
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

A DC-DC converter having a transformer, a reactance coil and a controllable switch for turning a DC supply voltage on and off. The contact gap of a switching transistor is set at a reference potential at a connecting tap between a primary winding and a secondary winding of the reactance coil, which is connected like a transformer with a certain transformation ratio. The anode-cathode segment of a diode and an output capacitor are set at reference potentials in series with the secondary winding of the reactance coil, with the output voltage for a load being applied across the output capacitor. The DC supply voltage is supplied to the primary winding of the reactance coil over an inductance arrangement, and a capacitance arrangement is arranged in parallel with the contact gap of the switching transistor so that a series resonant circuit, which is operative in the turn-on and turn-off phases of the switching transistor, is provided by the inductance arrangement and the capacitance arrangement.

Claims

1. A DC-DC voltage converter comprising:

an inductance arrangement;

a reactance coil, wherein;

the reactance coil includes a primary winding, a secondary winding and a connecting tap between the primary winding and the secondary winding;

the reactance coil is connected as a transformer to have a transformation ratio; and

a DC supply voltage is supplied to the primary winding of the reactance coil over the inductance arrangement;

a controllable switching transistor arrangement for turning on and off the DC supply voltage, wherein a contact gap of the controllable switching transistor arrangement is set at a reference potential at the connecting tap;

an output capacitor, wherein an output voltage for a load is applicable across the output capacitor;

a diode having an anode-cathode segment, wherein the anode-cathode segment of the diode and the output capacitor is set at the reference potential and is in series with the secondary winding of the reactance coil; and

a capacitance arrangement arranged in parallel with the contact gap of the controllable switching transistor arrangement so that a series resonant circuit, which is operative in a turn-on phase and a turn-off phase of the controllable switching transistor arrangement, is provided by the inductance arrangement and the capacitance arrangement.

2. The DC-DC converter of claim 1, wherein the controllable switching transistor arrangement is switched to a conducting state when a voltage applied to a conducting segment of the controllable switching transistor arrangement is approximately zero.

3. The DC-DC converter of claim 2, further comprising, a circuit arrangement for detecting a voltage applied to the conducting segment of the controllable switching transistor arrangement and for detecting zero crossings.

4. The DC-DC converter of claim 1, wherein the controllable switching transistor arrangement includes a MOS-FET transistor.

5. The DC-DC converter of claim 1, wherein the inductance arrangement, connected upstream from the primary winding, includes at least one of a discrete inductance arrangement and a leakage inductance of the reactance coil, the reactance coil having a coupling factor.

6. The DC-DC converter of claim 1, wherein the capacitance arrangement, parallel to the contact gap of the controllable switching transistor arrangement, is provided by at least one of a discrete capacitance arrangement and a parasitic output capacitance of the controllable switching transistor arrangement.

7. The DC-DC converter of claim 4, further comprising a gate resonance control arrangement, wherein a gate of the gate resonance control arrangement is used to control the MOS-FET transistor.

8. A gate resonance control arrangement for a DC-DC voltage converter, which comprises:

a gate reactance coil coupled upstream from a gate of the MOS-FET transistor, the MOS-FET transistor switching the DC supply voltage;

a first diode having a cathode-anode segment;

a first transistor switch;

a second diode having a anode-cathode segment;

a second transistor switch;

the gate reactance coil being connectable to a control voltage source across the cathode-anode segment of the first diode and the first transistor switch, and also being connectable to a reference potential across the anode-cathode segment of the second diode and the second transistor switch;

wherein;

the capacitance arrangement for the series resonant circuit includes at least one of a parasitic gate drain capacitance and a parasitic gate source capacitance; and

a clock pulse for switching on and off the first transistor switch and the second transistor switch is selected so that a gate voltage is escalated as desired.

9. The gate resonance control arrangement of claim 8, wherein the first transistor switch and the second transistor switch each include a bipolar transistor.

10. The DC-DC converter of claim 8, wherein the gate resonance control arrangement controls the MOS-FET transistor to switch the DC supply voltage.