Power supply switching apparatus

• US 5,530,296 A
• Filed: 12/30/1993
• Issued: 06/25/1996
• Est. Priority Date: 06/30/1993
• Status: Expired due to Term

• Current Assignee: Uniden Corporation (Cornwall Capital Management LP)
• Original Assignee: Uniden Corporation (Cornwall Capital Management LP)
• Inventors: Masaki, Tateo
• Primary Examiner(s): Shoop, Jr., William M.
• Assistant Examiner(s): KAPLAN, JONATHAN STUART
• Application Number:
  US08/176,397
• Time in Patent Office: 908 Days
• Field of Search: 307/64, 307/66, 307/75, 307/150, 307/80, 307/85, 320/2
• US Class Current: 307/75
• CPC Class Codes: H02J 7/0045 concerning the insertion or the connection of the batteries
• CPC Class Codes: Y10S 320/10 Nonbattery load controls charging

Abstract

A power supply switching apparatus for switching power supplies used to all electronic appliance such as a pager and a portable telephone is described. A battery pack includes a battery and is connectable to an external DC power supply. In the battery pack, a power supply connection detecting circuit detects whether or not the external DC power supply is connected to this battery pack, and a switching circuit switches the battery and the external DC power supply. In an appliance housing a voltage is detected by a voltage detecting circuit to judge whether the detected voltage corresponds to the voltage derived from the battery power supply, or the voltage derived from the external DC power supply, and another switching circuit switches the battery power supply and a power stabilizing circuit. Both of these battery pack and appliance housing constitute the power supply switching apparatus.

Claims

1. A power supply switching apparatus for a portable appliance for switching between a battery power supply and an external DC power supply, the battery power supply being housed in a battery pack, the battery pack providing a voltage to the portable appliance to which the battery pack is removably mounted, the apparatus comprising:

first apparatus located in said battery pack including;

means for connecting said battery pack to said external DC power supply;

means for selecting one of said battery power supply and said external DC power supply; and

means for applying a voltage of said selected power supply to said portable appliance, and

second apparatus located in said portable appliance including;

means for receiving the voltage applied from said battery pack;

means for detecting whether the received voltage corresponds to the voltage applied from said battery power supply, or the voltage applied from said external DC power supply;

a power stabilizing circuit for stabilizing the voltage from the external DC power supply to output a stabilized voltage; and

means for switching between the voltage from said means for receiving and the stabilized voltage from said power stabilizing circuit to output the switched voltage in response to an instruction from said detecting means.

2. A power supply switching apparatus for a portable appliance for switching between a battery power supply and an external DC power supply , the battery power supply being housed in a battery pack, the battery pack providing a voltage to the portable appliance to which the battery pack is removably mounted, the apparatus comprising:

first apparatus located in said battery pack including;

means for connecting said battery pack to said external DC power supply,

power supply connection detecting means for detecting whether or not said external DC power supply is connected to said battery pack;

first switching means for switching between said battery pack supply and said external DC power supply in response to an instruction issued from said power supply connection detecting means; and

means for applying the voltage of said switched power supply to said portable appliance; and

,

second apparatus located in said portable appliance including;

means for receiving the voltage applied from said battery pack;

means for detecting whether the received voltage corresponds to the voltage applied from said battery power supply, or the voltage applied from said external DC power supply;

a power stabilizing circuit for stabilizing the voltage from the external DC power supply to output a stabilized voltage; and

means for switching between the voltage from said means for receiving and the stabilized voltage from said power stabilizing circuit to output the switched voltage in response to an instruction from said means for detecting means.

3. A power supply switching apparatus for a portable appliance for switching between a battery power supply and an external DC power supply, the battery power supply being housed in a battery pack, the battery pack providing a voltage to the portable appliance to which the battery pack is removably mounted, said apparatus comprising:

first apparatus located in said battery pack including;

means for connecting said battery pack to said external DC power supply;

a power supply connection detecting circuit for detecting a connection of said external DC power supply to said battery pack;

a first switching circuit for switching between said battery power supply and said external DC power supply in response to an instruction issued from said power supply connection detecting circuit to output one of said voltages derived from said battery power supply and said external DC power supply; and

a first connection terminal for supplying the voltage output from said switching circuit to said portable appliance; and

,

second apparatus located in said portable appliance including;

a second connection terminal connected to said first connection terminal;

a voltage detecting circuit for detecting whether a voltage applied from said battery pack to said second terminal corresponds to the voltage derived from said battery power supply, or the voltage derived from said external DC power supply;

a power stabilizing circuit for stabilizing the voltage applied to said second connection terminal to output a constant voltage; and

a second switching circuit for switching between said second connection terminal and said power stabilizing circuit in response to an instruction issued from said voltage detecting circuit, and for applying the constant voltage derived from one of said second connection terminal and said power stabilizing circuit to a predetermined power source circuit of said portable appliance.

4. A power supply switching apparatus as claimed in claim 3, wherein:

said external DC power supply connection detecting circuit and said first switching circuit are constructed of a jack with a switch, wherein the jack receives a power supply plug by which said external DC power supply is connected to said battery pack; and

when said power supply plug is inserted into said jack, said switch is opened, thereby connecting said external DC power supply to said first connection terminal, and when said power supply plug is not connected to said jack, said switch is closed, thereby connecting said battery to said first connection terminal.

5. A power supply switching apparatus for a portable appliance for switching between a battery power supply and an external DC power supply, the battery power supply being housed in a battery pack, the battery pack providing a voltage to the portable appliance to which the battery pack is removably mounted, wherein:

said battery pack comprises;

a jack with a switch, said jack receiving a power supply plug for connecting said external DC power supply to said battery pack, said jack having a plus-sided contact and a minus-sided contact, said switch connecting the minus-sided contact to a minus polarity of said power supply, said switch being opened when said power supply plug is inserted into said jack, and said switch being closed when said power supply plug is not connected to said jack;

a first plus-sided connection terminal connected to said plus-sided contact of said jack and a positive polarity of said battery power supply; and

a first minus-sided connection terminal connected to said minus-sided contact of said jack and a positive polarity of said battery power supply; and

said portable appliance comprises;

a second plus-sided connection terminal connected to said first plus-sided connection terminal;

a second minus-sided connection terminal connected to said first minus-sided connection terminal;

a voltage detecting circuit including a series circuit constructed of a zener diode and a resistor, said series circuit connecting said second plus-sided connection terminal to said second minus-sided connection terminal, for detecting whether a voltage applied from said battery pack to said second plus-sided connection terminal and said second minus-sided connection terminal, corresponds to the voltage derived from said battery power supply, or the voltage derived from said external DC power supply;

a power stabilizing circuit connected to said second plus-sided connection terminal and said second minus-sided connection terminal, for stabilizing the voltage applied from said battery pack via said plus-sided connection terminal and said second minus-sided connection terminal; and

a switching circuit for switching between the voltage on said second plus-sided connection terminal and said second minus-sided connection terminal, and the output voltage from said power stabilizing circuit, thereby outputting one of said switched voltages.

6. A power supply switching apparatus as claimed in claim 5, wherein a recharging resistor connects the negative polarity of said battery and said minus-sided contact.

7. A power supply switching apparatus as claimed in claim 5, wherein a zener voltage of said zener diode is selected to be an intermediate voltage between the voltage of said battery power supply and the voltage of said external DC power supply.

8. A power supply switching apparatus for a portable appliance for switching between a battery power supply and an external DC power supply, the battery power supply being housed in a battery pack, battery pack providing a voltage to the portable appliance to which the battery pack is removably mounted, the apparatus comprising:

first apparatus located in said battery pack including;

means for connecting said battery pack to said external DC power supply;

an external DC power supply connection detecting circuit for detecting whether the external DC power supply is connected to said battery pack;

a recharging circuit for recharging said battery power supply housed in said battery pack when said external DC power supply is connected to said battery pack;

a switching circuit, responsive to said external DC power supply connection detecting circuit, for switching between said external DC power supply and said battery supply and for providing one of said external DC power supply and said battery supply to said portable appliance; and

second apparatus located in said portable appliance including;

a voltage detecting circuit for receiving a voltage from said battery pack and detecting whether the source of the voltage is said external DC power supply or said battery supply;

a power stabilizing circuit for stabilizing the voltage from said external DC power supply and providing a stabilized voltage; and

a switching circuit, responsive to said voltage detecting circuit, for switching between said voltage from said battery pack and said stabilized voltage and providing one of said voltage from said battery pack and said stabilized voltage to circuitry within said portable appliance.