AC to DC solid state power supply using high frequency pulsed power switching

• US 4,866,585 A
• Filed: 06/08/1988
• Issued: 09/12/1989
• Est. Priority Date: 06/08/1988
• Status: Expired due to Fees

• Current Assignee: Pawan K. Das
• Original Assignee: Pawan K. Das
• Inventors: Das, Pawan K.
• Primary Examiner(s): BEHA JR, WILLIAM
• Application Number:
  US07/203,915
• Time in Patent Office: 461 Days
• Field of Search: 363/8, 363/44, 363/45, 363/47, 363/48, 363/84, 363/88, 363/89, 363/129, 363/80, 363/81, 363/127, 323/282, 323/285
• US Class Current: 363/8
• CPC Class Codes: H02M 5/297 for conversion of frequency
• CPC Class Codes: H02M 7/219 in a bridge configuration

Abstract

A highly innovative new technique of developing AC to DC power sources for various applications has been described. Such technique of generating DC power is different from the conventional linear and switching power conversion techniques and this new technology has been called the Solid State Power Supply (SSPS) Technology. The principle of operation depends upon high-frequency pulsed power switching followed by high energy charge-discharge principles as applied to power conversion technology. The use of fast turn-on power MOSFETs enables the application of high frequency switching on this power technology. While the non-isolated SSPS is claimed to be transformerless, the isolated SSPS requires the use of a transformer for input-output isolation. The input and output filtering is reduced tremendously, thereby reducing the size of such power supplies. The SSPS technology is expected to revolutionize the 50/60/400 Hz power conversion technology and a compactness as much as 4:1 over the current 50KHz switching power supply is possible.

Claims

1. An isolated full wave rectified power supply device for generating DC power from an AC power source comprising:

auxiliary power supply means to generate an auxiliary DC power source which provides an input sense signal and the input to a reference voltage means to generate a reference voltage signal;

switching circuit means in circuit with the AC power source for switching on and off the AC power source and providing and output voltage;

high frequency transformer means receiving the output voltage from the switching circuit means and providing an isolated transformer output voltage;

output filter means for filtering the high frequency transformer output voltage to a DC output voltage;

signal isolation means receiving the DC output voltage and generating an isolated output sense signal; and

control circuit means utilizing the input sense signal and the output sense signal and modulating them with the reference voltage signal to generate positive pulse and negative pulse control signals to control the switching circuit means.

2. The device according to claim 1 wherein the switching circuit means is a controlled bridge rectifier including a diode in two limbs and a diode and a MOSFET device in series in the remaining two limbs, the circuit connected in such a way as to generate a full-wave rectified switched output when the MOSFETs are turned on and off.

3. The device according to claim 2 wherein the control circuit means further includes:

positive pulse detector means which, upon receiving the input sense signal, generates an output pulse in phase with the positive AC signal;

negative pulse detector means which, upon receiving the input sense signal or the output pulse of the positive pulse detector means, generate an output pulse in phase with the negative AC signal;

high frequency clock means for generating a high frequency clocking signal;

voltage regulation gating means in which the output of the high frequency clock means, when ANDed with the output sense signal, produces an output sensed gated clock;

positive pulse driver means in which the output of the positive pulse detector means, when ANDed with the output sensed gated clock, creates a positive pulse control signal; and

negative pulse driver means in which the output of the negative pulse detector means, when ANDed with the output sensed gated clock, creates a negative pulse control signal.

4. The device according to claim 3 wherein the positive pulse detector means further includes a comparator circuit, the negative input of which is maintained at a potential sllightly over ground potential and the positive input of which is connected to the input sense signal.

5. The device according to claim 3 wherein the negative pulse detector means further includes a comparator circuit, the negative input of which is connected to the output of the positive pulse detector means and the positive input of which is maintained at a positive potential.

6. The device according to claim 3 wherein the voltage regulation gating means further includes a comparator circuit, the negative input of which is connected to the output sense signal and the positive input of which is maintained at the reference voltage signal.

7. An isolated half wave rectified power supply device for generating DC power from an AC power source comprising:

auxiliary power supply means to generate an auxiliary DC power source which provides the input to a reference voltage means to generate a reference voltage signal;

switching circuit means in circuit with the AC power source for switching on and off the AC power source and providing an output voltage;

high frequency transformer means receiving the output voltage from the switching circuit means and providing an isolated transformer output voltage;

output filter means for filtering the high frequency transformer output voltage to a DC output voltage;

signal isolation means receiving the DC output voltage and generating an isolated output sense signal; and

control circuit means utilizing the output sense signal and the reference voltage signal to generate a gated clock control signal to control the switching circuit means.

8. The device according to claim 7 wherein the switching circuit means further includes a MOSFET in series with a diode, both connected in such a way in series with the high frequency transformer means that a half-wave rectified voltage is generated across the transformer means when the MOSFET is turned on.

9. The device according to claim 8 wherein the control circuit means further includes:

high frequency clock means providing a high frequency clock signal;

feedback comparator means in which the output sense signal and reference voltage signal produce a regulated gating signal; and

a NAND gated controlled means in which one input is the high frequency clock signal and the other input the regulated gating signal, the output of the NAND gated controlled means providing drive to turn on and off repeatedly the MOSFET of the switching circuit means.

10. The device according to claim 9 wherein the feedback comparator means comprises a comparator circuit, the negative input of which is connected to the output sense signal and the positive input is maintained at the reference voltage signal.