Title:
POWER SUPPLY SWITCHING CIRCUIT FOR PORTABLE TELEPHONE
Document Type and Number:
Japanese Patent JP3444903
Kind Code:
B2
Abstract:
PURPOSE: To permit the use of communicating function and logic function even when the voltage of a main battery lowers, in a portable telephone operated by the battery.
CONSTITUTION: A switching means 14 supplies the power supply voltage of a main battery 11 to a logic circuit 15 and a communication circuit 16 normally. When the output voltage of the main battery 11 lowers, a voltage lowness signal is outputted from a voltage monitoring means 13 and the switching means 14 switches the supply of a power from the main battery 11 to a sub-battery 12. Further, the supply of power to the communication circuit 16 is stopped by a power supply cutting means 17 when the power supply is switched from the main battery 11 to the sub-battery 12.
Inventors:
Kazuhiro Sato
Hiroyuki Hase
Hiroyuki Hase
Application Number:
JP4167792A
Publication Date:
September 08, 2003
Filing Date:
February 27, 1992
Export Citation:
Assignee:
富士通株式会社
International Classes:
H02J7/00; H02J9/06; H04B7/26; (IPC1-7): H02J9/06; H02J7/00; H04B7/26
Domestic Patent References:
| JP6158436A | ||||
| JP6165543A | ||||
| JP5713933A | ||||
| JP538057A | ||||
| JP5829327A | ||||
| JP5576644U |
Attorney, Agent or Firm:
Takeshi Hattori