GB1259719A - Improvements in and relating to circuit arrangements for polarity reversal of signals - Google Patents

Improvements in and relating to circuit arrangements for polarity reversal of signals

Info

Publication number
GB1259719A
GB1259719A GB61728/69A GB6172869A GB1259719A GB 1259719 A GB1259719 A GB 1259719A GB 61728/69 A GB61728/69 A GB 61728/69A GB 6172869 A GB6172869 A GB 6172869A GB 1259719 A GB1259719 A GB 1259719A
Authority
GB
United Kingdom
Prior art keywords
signal
input
amplifier
feedback
signals
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
GB61728/69A
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.)
Philips Electronics UK Ltd
Original Assignee
Philips Electronic and Associated Industries Ltd
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 Philips Electronic and Associated Industries Ltd filed Critical Philips Electronic and Associated Industries Ltd
Publication of GB1259719A publication Critical patent/GB1259719A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B14/00—Transmission systems not characterised by the medium used for transmission
    • H04B14/02—Transmission systems not characterised by the medium used for transmission characterised by the use of pulse modulation
    • H04B14/04—Transmission systems not characterised by the medium used for transmission characterised by the use of pulse modulation using pulse code modulation
    • H04B14/042—Special circuits, e.g. comparators
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
    • H03M1/00—Analogue/digital conversion; Digital/analogue conversion
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
    • H03M1/00—Analogue/digital conversion; Digital/analogue conversion
    • H03M1/12—Analogue/digital converters
    • H03M1/14—Conversion in steps with each step involving the same or a different conversion means and delivering more than one bit

Landscapes

  • Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Amplifiers (AREA)
  • Amplitude Modulation (AREA)
  • Electronic Switches (AREA)

Abstract

1,259,719. Polarity converters; detectors, demodulators. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. 18 Dec., 1969 [21 Dec., 1968], No. 61728/69. Heading H3T. [Also in Division G4] A circuit for converting signals from bipolar to monopolar form or vice versa comprises an amplifier 21, 22 or 15 having two negative feedback paths, each including a diode or other switching device 5, 6 or 45, 46, connected to the amplifier input via a resistor 11, 12, the input signals being applied via respective resistors 9, 10 to the two resistor, switching device junctions. The circuit is described as used in the modulator and demodulator of a pulse code modulation system in which speech is transmitted in the form of a polarity indicating pulse followed by a code group representing the rectified signal amplitude. In the speech signal rectifier of Fig. 1 the positive going part of the input-signal 18 causes the amplifier output to go negative causing the feedback path through diode 6 to become effective. This produces a virtual earth at the amplifier input and as resistors 10 and 11 are equal the signal at 17 is of half the input signal amplitude. Negative going parts of the signal render the feedback through diode 5 effective and the signal output at 17 is again of half the input signal amplitude but now of opposite polarity to the input. The resulting monopolar output from 17 is applied via an amplifier 8 to a pulse code modulator 7. The input signal may alternatively be applied via a transformer to points 13 and 14 and a balanced output may be obtained from 16 and 17. The amplifier has a source follower input stage and feedback through a low-pass filter 28- 31 to maintain D.C. stability. Fig. 2 shows the demodulator for the coded signals received at 32. The polarity signal is deleted at 34 and the signal decoded and sampled at 35 to recover the rectified signals at 37. The polarity indicating component is extracted at 38 and used to provide opposite polarity control signals at the output of a bistable circuit 42 which switch the feedback paths of a circuit similar to Fig. 1 but comprising feedback transistors 49, 48 instead of the diodes. The circuit inverts alternate parts of the signal 37 to provide the bipolar signal 48. This is amplified at 49 and applied to a time multiplex distributor 50.
GB61728/69A 1968-12-21 1969-12-18 Improvements in and relating to circuit arrangements for polarity reversal of signals Expired GB1259719A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL6818490A NL6818490A (en) 1968-12-21 1968-12-21

Publications (1)

Publication Number Publication Date
GB1259719A true GB1259719A (en) 1972-01-12

Family

ID=19805469

Family Applications (1)

Application Number Title Priority Date Filing Date
GB61728/69A Expired GB1259719A (en) 1968-12-21 1969-12-18 Improvements in and relating to circuit arrangements for polarity reversal of signals

Country Status (10)

Country Link
US (1) US3624414A (en)
JP (1) JPS4928781B1 (en)
AT (1) AT297096B (en)
BE (1) BE743445A (en)
CH (1) CH503428A (en)
DE (1) DE1960699B2 (en)
FR (1) FR2026815A1 (en)
GB (1) GB1259719A (en)
NL (1) NL6818490A (en)
SE (1) SE352503B (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1458499A (en) * 1972-11-09 1976-12-15 Square D Co Logic systems
IT1108198B (en) * 1978-09-13 1985-12-02 Cselt Centro Studi Lab Telecom IMPROVEMENTS TO DIGITAL ANALOG CODERS
US4228368A (en) * 1978-10-26 1980-10-14 Orban Robert A Polarity correcting circuit
EP0069183B1 (en) * 1981-06-25 1985-09-18 International Business Machines Corporation Method and device for transmitting logic signals between micro chips
JPS6335309U (en) * 1986-08-23 1988-03-07
US4860311A (en) * 1987-05-01 1989-08-22 Cpt Corporation Method and apparatus for automatically converting input pulse train signals to output signals of desired polarity

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3130325A (en) * 1960-08-01 1964-04-21 Electronic Associates Electronic switch having feedback compensating for switch nonlinearities
US3112449A (en) * 1961-09-29 1963-11-26 Gen Electric Converter for converting alternating current signals to proportional constant polarity signals including compensating diode feedback
US3196291A (en) * 1963-03-18 1965-07-20 Gen Electric Precision a.c. to d.c. converter
US3311835A (en) * 1963-03-22 1967-03-28 Weston Instruments Inc Operational rectifier
US3480794A (en) * 1966-10-20 1969-11-25 Weston Instruments Inc Parallel operational rectifiers
US3509372A (en) * 1967-11-22 1970-04-28 Honeywell Inc Operational amplifier controlling opposite-conductivity type switches for providing unipolar output proportional to absolute value of input signal

Also Published As

Publication number Publication date
BE743445A (en) 1970-06-19
JPS4928781B1 (en) 1974-07-30
CH503428A (en) 1971-02-15
US3624414A (en) 1971-11-30
DE1960699B2 (en) 1976-06-10
SE352503B (en) 1972-12-27
NL6818490A (en) 1970-06-23
AT297096B (en) 1972-03-10
FR2026815A1 (en) 1970-09-18
DE1960699A1 (en) 1970-07-09

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Legal Events

Date Code Title Description
PS Patent sealed [section 19, patents act 1949]
PCNP Patent ceased through non-payment of renewal fee