GB1298449A - Improvements in or relating to telephone instruments - Google Patents

Improvements in or relating to telephone instruments

Info

Publication number
GB1298449A
GB1298449A GB6919/70A GB691970A GB1298449A GB 1298449 A GB1298449 A GB 1298449A GB 6919/70 A GB6919/70 A GB 6919/70A GB 691970 A GB691970 A GB 691970A GB 1298449 A GB1298449 A GB 1298449A
Authority
GB
United Kingdom
Prior art keywords
transistors
battery
relating
zener diode
telephone instruments
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB6919/70A
Inventor
Robert Andrew Stevenson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
General Electric Co PLC
Original Assignee
General Electric Co PLC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by General Electric Co PLC filed Critical General Electric Co PLC
Priority to GB6919/70A priority Critical patent/GB1298449A/en
Priority to ZA710885A priority patent/ZA71885B/en
Priority to AU25396/71A priority patent/AU2539671A/en
Publication of GB1298449A publication Critical patent/GB1298449A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M19/00—Current supply arrangements for telephone systems
    • H04M19/08—Current supply arrangements for telephone systems with current supply sources at the substations

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Charge And Discharge Circuits For Batteries Or The Like (AREA)
  • Secondary Cells (AREA)

Abstract

1298449 Charging batteries GENERAL ELECTRIC CO Ltd 19 April 1971 [12 Feb 1970] 6919/70 Heading H2H [Also in Division H4] A circuit for charging a battery 8 comprises transistors 13, 16 connected with a Zener diode 14 across the output of a full wave rectifier 10. When the battery voltage is low the transistors are non-conductive but when the battery is full charged the transistors conduct to provide a low impedance shunt path. It is stated that a Zener diode only could be used.
GB6919/70A 1970-02-12 1970-02-12 Improvements in or relating to telephone instruments Expired GB1298449A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
GB6919/70A GB1298449A (en) 1970-02-12 1970-02-12 Improvements in or relating to telephone instruments
ZA710885A ZA71885B (en) 1970-02-12 1971-02-12 Improvements in or relating to telephone instruments
AU25396/71A AU2539671A (en) 1970-02-12 1971-02-12 Improvements in or relating to telephone instruments

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB6919/70A GB1298449A (en) 1970-02-12 1970-02-12 Improvements in or relating to telephone instruments

Publications (1)

Publication Number Publication Date
GB1298449A true GB1298449A (en) 1972-12-06

Family

ID=9823253

Family Applications (1)

Application Number Title Priority Date Filing Date
GB6919/70A Expired GB1298449A (en) 1970-02-12 1970-02-12 Improvements in or relating to telephone instruments

Country Status (3)

Country Link
AU (1) AU2539671A (en)
GB (1) GB1298449A (en)
ZA (1) ZA71885B (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2282198A1 (en) * 1974-08-12 1976-03-12 Trt Telecom Radio Electr Keyboard telephone for long lines - uses speech loop current to power MOS circuit
GB2242793A (en) * 1990-04-05 1991-10-09 Technophone Ltd Battery charger for portable electronic apparatus

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2282198A1 (en) * 1974-08-12 1976-03-12 Trt Telecom Radio Electr Keyboard telephone for long lines - uses speech loop current to power MOS circuit
GB2242793A (en) * 1990-04-05 1991-10-09 Technophone Ltd Battery charger for portable electronic apparatus
US5254931A (en) * 1990-04-05 1993-10-19 Nokia Mobile Phones Ltd. Battery charging apparatus in a portable electronic apparatus
GB2242793B (en) * 1990-04-05 1994-08-10 Technophone Ltd Battery charging apparatus

Also Published As

Publication number Publication date
ZA71885B (en) 1972-02-23
AU2539671A (en) 1972-08-17

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Legal Events

Date Code Title Description
PS Patent sealed
PLNP Patent lapsed through nonpayment of renewal fees