Switching power supply utilizing switch-selectable resistors to determine output voltage

• US 7,450,403 B2
• Filed: 08/09/2007
• Issued: 11/11/2008
• Est. Priority Date: 04/26/1994
• Status: Expired due to Fees

• Current Assignee: Comarco Wireless Technologies Incorporated (Comarco Incorporated)
• Original Assignee: Comarco Wireless Technologies Incorporated (Comarco Incorporated)
• Inventors: Lanni, Thomas W.
• Primary Examiner(s): BERHANE, ADOLF D
• Application Number:
  US11/891,187
• Publication Number:
  US 20070279952A1
• Time in Patent Office: 460 Days
• Field of Search: 363/17, 363/20, 363/21, 363/24, 363/25, 363/28, 363/79, 363/80, 363/97, 363/98, 363/132, 363/21.01
• US Class Current: 363/21.01
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C
• CPC Class Codes: H01F 2027/2819 Planar transformers with printed windings, e.g. surrounded by two cores and to be mounted on printed circuit
• CPC Class Codes: H01R 13/24 resilient; resiliently-mounted
• CPC Class Codes: H01R 13/6675 with built-in power supply
• CPC Class Codes: H01R 2201/16 for telephony
• CPC Class Codes: H01R 2201/24 for radio transmission
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 7/00041 in response to measured battery parameters, e.g. voltage, current or temperature profile
• CPC Class Codes: H02J 7/00047 with provisions for charging different types of batteries
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters
• CPC Class Codes: H02M 1/4258 using a single converter stage both for correction of AC input power factor and generation of a regulated and galvanically isolated DC output voltage H02M1/4241 takes precedence
• CPC Class Codes: H02M 3/003 Constructional details, e.g. physical layout, assembly, wiring or busbar connections
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators
• 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 3/33507 with automatic control of the output voltage or current, e.g. flyback converters H02M3/33561, H02M3/33569 take precedence
• CPC Class Codes: H02M 3/33523 with galvanic isolation between input and output of both the power stage and the feedback loop
• CPC Class Codes: H02M 3/3372 of the parallel type
• CPC Class Codes: H02M 3/3378 in a push-pull configuration of the parallel type H02M3/3374 takes precedence
• CPC Class Codes: H02M 3/3382 in a push-pull circuit arrangement
• CPC Class Codes: H02M 3/3387 : in a push-pull configuration
• CPC Class Codes: H02M 7/003 : Constructional details, e.g. physical layout, assembly, wiring or busbar connections
• CPC Class Codes: H05K 1/0203 : Cooling of mounted components H05K1/0272 takes precedence
• CPC Class Codes: H05K 1/0262 : Arrangements for regulating voltages or for using plural voltages
• CPC Class Codes: H05K 1/029 : having a programmable lay-out, i.e. adapted for choosing between a few possibilities
• CPC Class Codes: H05K 1/16 : incorporating printed electric components, e.g. printed resistor, capacitor, inductor
• CPC Class Codes: H05K 1/165 : incorporating printed inductors
• CPC Class Codes: H05K 2201/086 : for inductive purposes, e.g. printed inductor with ferrite core
• CPC Class Codes: H05K 2201/09063 : Holes or slots in insulating substrate not used for electrical connections
• CPC Class Codes: Y02B 40/00 : Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers
• 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 switching power supply includes a source of DC voltage and a transformer having primary and secondary windings. A switching circuit is coupled between the DC voltage and the primary winding to provide alternating current to the primary winding. A rectifier circuit is coupled to the secondary winding to provide a DC output voltage. A controller circuit controls the switching circuit to modulate the alternating current provided to the primary winding. A circuit receives a first input signal having a magnitude which is determined by the DC output voltage and a second input signal having a magnitude which is determined by a selected position of a multiposition switch. An output of the circuit generates a feedback signal which is coupled to the controller circuit.

Claims

1. A power supply comprising:

a terminal for receiving a DC voltage;

a transformer having a primary winding and a secondary winding;

a switching circuit coupled between the terminal and the primary winding for providing alternating current to the primary winding;

a rectifier circuit coupled to the secondary winding to provide a DC output voltage;

a controller circuit for controlling the switching circuit to modulate the alternating current provided to the primary winding; and

a circuit which generates an output signal having a magnitude which is a function of the DC output voltage and a selected position of a switch, the switch being operable to selectively couple a component, from among a plurality of components, to an input of the circuit, and the output signal being provided as a feedback signal to the controller circuit to control a magnitude of the DC output voltage.

2. The power supply according to claim 1, wherein the input of the circuit is coupled to a reference voltage via the switch and the component, and a second input of the circuit is coupled to the DC output voltage.

3. The power supply according to claim 1, wherein the switch is settable to one of a plurality of selectable positions and has a connection point corresponding to each of the selectable positions, each connection point being coupled to a corresponding component.

4. The power supply according to claim 3, wherein each of the connection points is coupled to the corresponding component at a first end of the corresponding component, and second ends of the components are coupled to a reference voltage.

5. The power supply according to claim 1, wherein the component is a resistor.

6. The power supply according to claim 1, wherein the DC voltage is provided to the terminal from a DC power source external to the power supply.

7. The power supply according to claim 1, wherein the DC voltage is provided to the terminal from an input circuit internal to the power supply, the input circuit including a rectifier and being coupled to an AC power source external to the power supply.

8. The power supply according to claim 1, wherein the switch is a mechanical switch.

9. The power supply according to claim 1, wherein the switch is an electronic switch.

10. The power supply according to claim 1, including a driver circuit coupled between the controller circuit and the switching circuit, and wherein the circuit is an amplifier.

11. A power supply comprising:

a .terminal for receiving a DC voltage;

a transformer having a primary winding and a secondary winding;

a switching circuit coupled between the terminal and the primary winding for providing alternating current to the primary winding;

ectifier circuit coupled to the secondary winding to provide a DC output voltage;

a controller circuit for controlling the switching circuit to modulate the alternating current provided to the primary winding; and

a circuit which generates an output signal having a magnitude which is a function of the DC output voltage and a selected position of a switch, wherein the switch is not utilized to couple the DC output voltage to a device to be powered by the power supply, and the output signal is provided as a feedback signal to the controller circuit to control a magnitude of the DC output voltage.

12. The power supply of claim 11, wherein the switch is operable to selectively couple a component, from among a plurality of components, to an input of the circuit.

13. The power supply of claim 12, wherein the input of the circuit is coupled to a reference voltage via the switch and a selected component, and a second input of the circuit is coupled to the DC output voltage.

14. The power supply of claim 12, wherein the switch is settable to one of a plurality of selectable positions and has a connection point corresponding to each of the selectable positions, each connection point being coupled to a corresponding component.

15. The power supply of claim 14, wherein each connection point is coupled to the corresponding component at a first end of the corresponding component, and second ends of the components are coupled to a reference voltage.

16. The power supply of claim 12, wherein the component is a resistor.

17. The power supply of claim 11, wherein the DC voltage is provided to the terminal from a DC power source external to the power supply.

18. The power supply according to claim 11, wherein the DC voltage is provided to the terminal from an input circuit internal to power supply, the input circuit including a rectifier and being coupled to an AC power source external to the power supply.

19. The power supply according to claim 11, wherein the switch is a mechanical switch.

20. The power supply according to claim 11, wherein the switch is an electronic switch.

21. The power supply according to claim 11, including a driver circuit coupled between the controller and the switching circuit, and wherein the circuit is an amplifier.