Resonant rectifier circuit

• US 4,685,041 A
• Filed: 08/08/1986
• Issued: 08/04/1987
• Est. Priority Date: 03/11/1985
• Status: Expired due to Term

• Current Assignee: American Telephone & Telegraph Company (AT&T, Inc.), Bell Telephone Laboratories, Inc. (Nokia Corporation)
• Original Assignee: American Telephone & Telegraph Company (AT&T, Inc.)
• Inventors: Bowman, Wayne C., Ziesse, Norman G., Magalhaes, Frank M., Suiter, Weyman B. Jr.
• Primary Examiner(s): Salce, Patrick R.
• Assistant Examiner(s): Voeltz, Emanuel Todd
• Application Number:
  US06/894,978
• Time in Patent Office: 361 Days
• Field of Search: 363/39, 363/44-48, 363/126, 363/131, 363/21, 363/40, 363/97
• US Class Current: 363/40
• CPC Class Codes: H02M 3/28 using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
• CPC Class Codes: H02M 3/338 in a self-oscillating arrangement H02M3/337 takes precedence
• CPC Class Codes: H02M 7/4818 with means for adaptation of resonance frequency, e.g. by modification of capacitance or inductance of resonance circuits
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

A self-oscillating power converter utilizes a MOSFET power transistor switch with its output electrode coupled to a tuned network that operatively limits the voltage waveform across the power switch to periodic unipolar pulses. The transistor switch may be operated at a high radio frequency so that its drain to gate interelectrode capacitance is sufficient to comprise the sole oscillatory sustaining feedback path of the converter. A reactive network which is inductive at the operating frequency couples the gate to source electrodes of the transistor switch and includes a variable capacitance as a means of adjusting the overall reactance, and hence the converter'"'"'s switching frequency in order to provide voltage regulation. A resonant rectifier includes a tuned circuit to shape the voltage waveform across the rectifying diodes as a time inverse of the power switch waveform. The input resistance of the rectifier is controlled so that it is invariant to frequency change within the switching frequency range of the converter but inversely proportional to the load resistance.

Claims

1. A power rectifying circuit comprising:

an input for accepting a high frequency, substantially sinusoidal signal lying within a predefined operating frequency range,

an output for accepting a load to be energized,

a first inductance associated with the input,

a first capacitance associated with the input,

a network, including a rectifying diode coupling the input to the output, the diode including significant adjunct capacitance,

a second inductance included within the network,

a second capacitance included within the network and including the adjunct capacitance,

the first and second capacitance and the first and second inductance being tuned to obtain first and second frequency response poles in an impedance of the input selected such that the first and second frequency response poles are bracketing a predefined frequency range of the sinusoidal signal and further having network quality adjusted so that a resistive component of impedance at the input is substantially invariant with respect to frequency variations of the high frequency signal over the predefined operating frequency range.

4. A power rectifying circuit as defined in claims 1, 2, or 3 wherein the input includes a transformer.

5. A power rectifying circuit as defined in claim 4 wherein the second inductance includes a leakage inductance of the transformer.

6. A power rectifying circuit as defined in claim 4 wherein the first inductance includes a magnetizing inductance of the transformer.

7. A power rectifying circuit as defined in claim 4 wherein the first inductance includes a magnetizing inductance of the transformer and the second inductance includes a leakage inductance of the transformer.

8. A power rectifying circuit as defined in claim 1, 2, or 3 and further including means for filtering a rectified signal to obtain a substantially DC output.

9. A power rectifying circuit as defined in claim 1, 2, or 3 wherein the network includes a second rectifying diode having significant adjunct capacitance and being connected to conduct alternately with the first rectifying diode.

10. A power rectifying circuit as defined in claim 1, 2, or 3 wherein the second capacitance includes a discrete capacitance shunting the rectifying diode.

2. A power rectifying circuit comprising:

an input for accepting a high frequency, substantially sinusoidal signal lying within a predefined operating frequency range,

an output for accepting a load to be energized,

a first inductance associated with the input,

a first capacitance associated with the input,

a network, including a rectifying diode coupling the input to the output, the diode including significant adjunct capacitance,

a second inductance included within the network,

a second capacitance included within the network and including the adjunct capacitance,

the first and second capacitance and the first and second inductance being tuned and adapted to achieve a network quality adjusted to provide an LC impedance transformation between the input and output so that a resistive component of impedance of the input varies inversely with a change of a resistance value of the load.

3. A power rectifying circuit comprising:

an input for accepting a high frequency, substantially sinusoidal signal lying within a predefined operating frequency range,

an output for accepting a load to be energized,

a first inductance associated with the input,

a first capacitance associated with the input,

a network including a rectifying diode coupling the input to the output, the rectifying diode including significant adjunct capacitance,

a second inductance included within the network,

a second capacitance included within the network and including the adjunct capacitance,

the first and second capacitance and the first and second inductance being tuned to obtain first and second frequency response poles in an impedance of the input selected such that the first and second frequency response poles are bracketing a predefined operating frequency range of the sinusoidal signal so that a resistive component of impedance at the input is substantially invariant with respect to frequency variations of the high frequency signal over a predetermined operating frequency range, and further having a network quality adjusted so that an LC impedance transformation between the input and output assures that a resistive impedance of the input varies inversely with a change of a resistance value of the load.

11. A power rectifying circuit for a power converter circuit having an inverter circuit generating a substantially sinusoidal signal and an energy transfer between the inverter and the rectifying circuit being substantially at a single frequency lying within a defined regulatory frequency range, comprising:

an input for accepting a substantially sinusoidal signal,

an output for supplying a load,

a rectifying diode located intermediate to the input and output,

a first inductive reactance at the input,

a first capacitive reactance at the input,

a second inductive reactance within the rectifying circuit, a second capacitive reactance including adjunct capacitance of the rectifying diode within the rectifying circuit, the first and second inductive reactance and the first and second capacitive reactance being tuned to establish first and second frequency response poles in an impedance of the input,

the first and second frequency response poles selected to bracket the defined regulatory frequency range whereby a resistive component of impedance at the input is substantially invariant to frequency change within the defined regulatory frequency range.

14. A power rectifying circuit as defined in claims 11, 12, or 13 wherein the input includes a transformer.

15. A power rectifying circuit as defined in claim 14 wherein the first inductive reactance includes a magnetizing inductance of the transformer.

16. A power rectifying circuit as defined in claim 14 wherein the second inductive reactance includes a leakage inductance of the transformer.

17. A power rectifying circuit as defined in claim 14 wherein the first inductive reactance includes a magnetizing inductance of the transformer, and the second inductive reactance includes a leakage inductance of the transformer.

18. A power rectifying circuit as defined in claim 11, 12 or 13 wherein the second capacitive reactance includes a discrete capacitor shunting the rectifying diode.

19. A rectifying circuit as defined in claim 11, 12 or 13 and further including a second rectifying diode including significant adjunct capacitance and connected to conduct alternately with the first rectifying diode.

20. A power rectifying circuit as defined in claim 11, 12, or 13 and further including means for filtering a rectified signal to obtain a substantially DC output.

12. A power rectifying circuit for a power converter circuit having an inverter circuit generating a substantially sinusoidal signal and an energy transfer between the inverter and the power rectifying circuit being substantially at a single frequency lying within a defined regulatory frequency range, comprising:

an input for accepting a substantially sinusoidal signal,

an output for supplying a load,

a rectifying diode located intermediate to the input and output,

a first inductive reactance at the input,

a first capacitive reactance at the input,

a second inductive reactance within the rectifying circuit, a second capacitive reactance including adjunct capacitance of the rectifying diode within the rectifying circuit, the first and second inductive reactance and the first and second capacitive reactance being selected for providing an LC impedance transformation between the input and the output such that a resistive component of impedance at the input varies inversely with a load resistance at the output.

13. A power rectifying circuit for a power converter circuit having an inverter circuit generating a substantially sinusoidal signal and an energy transfer between the inverter and the power rectifying circuit being substantially at a single frequency within a defined regulatory frequency range, comprising:

an input for accepting a substantially sinusoidal signal,

an output for supplying a load,

a rectifying diode located intermediate to the input and output,

a first inductive reactance at the input,

a first capacitive reactance at the input,

a second inductive reactance within the rectifying circuit, a second capacitive reactance including adjunct capacitance of the rectifying diode within the rectifying circuit, the first and second inductive reactances and the first and second capacitive reactances being tuned to establish first and second frequency response poles in an impedance of the input,

the first and second frequency response poles selected to bracket the defined regulatory frequency range whereby a resistive component of impedance at the input is substantially invariant to frequency change within the defined regulatory frequency range, and a circuit quality of the power rectifier further being adapted for providing LC impedance transformation between the input and the output such that a resistive component of impedance at the input varies inversely with load resistance at the output.