Power supply

• US 20040027099A1
• Filed: 03/27/2003
• Published: 02/12/2004
• Est. Priority Date: 09/28/2000
• Status: Active Grant

• Current Assignee: Citizen Holdings Co., Ltd.
• Original Assignee: Citizen Watch Co Limited (Citizen Electronics Company Limited)
• Inventors: Fujii, Masashi
• Granted Patent: US 6,815,935 B2
• Time in Patent Office: Days
• US Class Current: 323/234
• CPC Class Codes: G06F 1/263 Arrangements for using multiple switchable power supplies, e.g. battery and AC G06F1/30 takes precedence
• CPC Class Codes: G06F 1/32 Means for saving power
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 7/34 Parallel operation in networks using both storage and other dc sources, e.g. providing buffering H02J7/14 takes precedence
• CPC Class Codes: H02J 9/005 using a power saving mode for copiers G03G15/5004
• CPC Class Codes: H02J 9/061 for DC powered loads
• CPC Class Codes: H02M 1/0012 Control circuits using digital or numerical techniques in DC/DC converters H02M3/157, H02M3/33515; in DC-AC converters H02M7/53873
• CPC Class Codes: H02M 1/0032 Control circuits allowing low power mode operation, e.g. in standby mode
• CPC Class Codes: H02M 1/0045 Converters combining the concepts of switch-mode regulation and linear regulation, e.g. linear pre-regulator to switching converter, linear and switching converter in parallel, same converter or same transistor operating either in linear or switching mode
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators
• CPC Class Codes: H02M 3/157 with digital control
• CPC Class Codes: H02M 3/1584 with a plurality of power processing stages connected in parallel
• 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 power supply in which power conversion efficiency is enhanced in all operation modes by supplying power to a load (60) from any one or both of first power supply circuit (20) and second power supply circuit (40), detecting the operation mode of the load (60) through an operation mode detecting means (65), and controlling switches (11,12) depending on the operation mode of the load (60) to select a power supply circuit for supplying power to the load (60).

Claims

1. A power supply comprising:

a battery;

a power supply circuit connected with the battery for supplying power to a load, wherein the power supply circuit consists of a plurality of power supply circuits which are able to connect in parallel with one another;

an operation mode detecting means for detecting an operation mode of the load; and

a power supply circuit selecting means for switching any one of or multiple combinations of the plurality of power supply circuits for supplying power to the load, depending on the operation mode detected by the operation mode detecting means.

2. A power supply according to claim 1, wherein the plurality of power supply circuits are differentiated in a circuit type or power supply capacity.

3. A power supply according to claim 1, wherein the plurality of power supply circuits comprise a first power supply circuit which is a switching regulator circuit type and a second power supply circuit which is a linear regulator circuit type;

and wherein the power supply circuit selecting means allows the first power supply circuit and the second power supply circuit to supply power to the load if the operation mode of the load is a full mode or an idle mode, while it allows only the second power supply circuit to supply power to the load if the operation mode is a stop mode.

4. A power supply according to claim 1, wherein a CPU is provided in the load, and the operation mode detecting means consists of the CPU per se, or a means for detecting the operation mode of the load in response to a signal issued by the CPU and representing the operation state.

5. A power supply according to claim 1, wherein the operation mode detecting means may comprise a shunt resistor interposed in a power supply line extending from the power supply circuit to the load, an operational amplifier for detecting a voltage generated between both ends of the shunt resistor in proportion to a value of current flowing in the shunt resistor, and a comparator for comparing a voltage detected by the operational amplifier with a reference voltage.