IE41644L - Power supply circuits - Google Patents

Power supply circuits

Info

Publication number
IE41644L
IE41644L IE751702A IE170275A IE41644L IE 41644 L IE41644 L IE 41644L IE 751702 A IE751702 A IE 751702A IE 170275 A IE170275 A IE 170275A IE 41644 L IE41644 L IE 41644L
Authority
IE
Ireland
Prior art keywords
diode
arrangement
transistor
zener diode
loop
Prior art date
Application number
IE751702A
Other versions
IE41644B1 (en
Original Assignee
Int Standard Electric Corp
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 Int Standard Electric Corp filed Critical Int Standard Electric Corp
Publication of IE41644L publication Critical patent/IE41644L/en
Publication of IE41644B1 publication Critical patent/IE41644B1/en

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M1/00—Substation equipment, e.g. for use by subscribers
    • H04M1/26—Devices for calling a subscriber
    • H04M1/30—Devices which can set up and transmit only one digit at a time
    • H04M1/31—Devices which can set up and transmit only one digit at a time by interrupting current to generate trains of pulses; by periodically opening and closing contacts to generate trains of pulses
    • H04M1/312—Devices which can set up and transmit only one digit at a time by interrupting current to generate trains of pulses; by periodically opening and closing contacts to generate trains of pulses pulses produced by electronic circuits
    • 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)
  • Devices For Supply Of Signal Current (AREA)

Abstract

1472442 Sub-station circuits STANDARD TELEPHONES & CABLES Ltd 30 July 1974 33570/74 Heading H4K A power supply arrangement for maintaining power to the circuitry of a telephone set during loop disconnect signalling comprises a capacitor C charged from the exchange battery via a rectifier bridge 3 and an arrangement of a Zener diode ZD and transistors TR1, TR2. The arrangement of the Zener diode and transistors is such as to ensure that the voltage across capacitor C is mainteined at or below a predetermined limit: To improve the response of the circuit to low line voltages and currents the slope resistance of the Zener diode can be reduced by connecting a parallel arrangement of a resistor and the collector base junction of a transistor in series with the diode, the collector emitter junction of the transistor being connected in the line loop (Fig. 2, not shown). The rectifier bridge 3 may be a diode bridge, or a transistor diode bridge as shown in Fig. 3. The load L may be the circuitry of a pushbutton type dialling apparatus of the type in which the actuation of a push-button causes loop-disconnect impulses to be transmitted. [GB1472442A]
IE1702/75A 1974-07-30 1975-07-29 Improvements in or relating to power supply circuits IE41644B1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB3357074A GB1472442A (en) 1974-07-30 1974-07-30 Power supply circuits

Publications (2)

Publication Number Publication Date
IE41644L true IE41644L (en) 1976-01-30
IE41644B1 IE41644B1 (en) 1980-02-27

Family

ID=10354661

Family Applications (1)

Application Number Title Priority Date Filing Date
IE1702/75A IE41644B1 (en) 1974-07-30 1975-07-29 Improvements in or relating to power supply circuits

Country Status (8)

Country Link
BE (1) BE831828A (en)
FR (1) FR2281019A1 (en)
GB (1) GB1472442A (en)
HK (1) HK5878A (en)
IE (1) IE41644B1 (en)
IT (1) IT1039852B (en)
NZ (1) NZ178241A (en)
ZA (1) ZA754856B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2931464C2 (en) * 1979-08-02 1981-10-08 Siemens AG, 1000 Berlin und 8000 München Circuit arrangement for connecting a transmission device of a modem to a telephone line
DE2931456C2 (en) * 1979-08-02 1982-10-28 Siemens AG, 1000 Berlin und 8000 München Parallel control circuit

Also Published As

Publication number Publication date
ZA754856B (en) 1976-09-29
IT1039852B (en) 1979-12-10
HK5878A (en) 1978-02-03
GB1472442A (en) 1977-05-04
IE41644B1 (en) 1980-02-27
FR2281019A1 (en) 1976-02-27
FR2281019B3 (en) 1979-04-27
BE831828A (en) 1976-01-29
NZ178241A (en) 1978-03-06

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