DK160170B - CIRCUIT DEVICE FOR COMPRESSION OF NOISE SIGNALS - Google Patents

CIRCUIT DEVICE FOR COMPRESSION OF NOISE SIGNALS Download PDF

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Publication number
DK160170B
DK160170B DK168184A DK168184A DK160170B DK 160170 B DK160170 B DK 160170B DK 168184 A DK168184 A DK 168184A DK 168184 A DK168184 A DK 168184A DK 160170 B DK160170 B DK 160170B
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Prior art keywords
time constant
signals
transistor
output stage
output
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DK168184A
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Danish (da)
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DK168184D0 (en
DK160170C (en
DK168184A (en
Inventor
Guenter Gleim
Dieter Baas
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Thomson Brandt Gmbh
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Publication of DK160170C publication Critical patent/DK160170C/en

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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
    • H03J9/00—Remote-control of tuned circuits; Combined remote-control of tuning and other functions, e.g. brightness, amplification
    • H03J9/06—Remote-control of tuned circuits; Combined remote-control of tuning and other functions, e.g. brightness, amplification using electromagnetic waves other than radio waves, e.g. light
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/60—Receivers
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K5/00—Manipulating of pulses not covered by one of the other main groups of this subclass
    • H03K5/125—Discriminating pulses
    • H03K5/1252—Suppression or limitation of noise or interference

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Nonlinear Science (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Dc Digital Transmission (AREA)
  • Noise Elimination (AREA)
  • Optical Communication System (AREA)
  • Manipulation Of Pulses (AREA)
  • Logic Circuits (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
  • Reduction Or Emphasis Of Bandwidth Of Signals (AREA)
  • Amplifiers (AREA)
  • Electronic Switches (AREA)

Abstract

1. A circuit configuration for the purpose of suppressing interference pulses when transmitting digital signals of variable time spacing and amplitudes, comprizing a number of time constant elements (4, 5, 6, 7), whereby the received signals are connected to an amplifier (V1), to whose output is connected a rectifier (3), which connects the rectified signal voltage across the time constant elements to an output stage (V2), this consisting of at least one transistor (8), whereby the time constant (T1) of the first time constant element (4, 5, 6), which is dimensioned according to the greatest spacing of the useful signals (N), is appreciably greater than the time constant of the second time constant element (5, 7), this being dimensioned according to the shortest spacing of the useful signals (N), characterised in that the time constant element (5, 7) which has the smaller time constant (T2) is connected to the output stage (V2) in such a manner that the quiescent dc voltage level, which is pending on the time-constant element, does not fall below the operating voltage level that has been reduced by the base-emitter voltage of the transistor (8) in the output stage (V2), the emitter of which is connected to the stabilized operating voltage source (UB ), and that output signals that are freed of noise signals may be tapped from a resistor (9) which is included in the collector circuit of the transistor (8).

Description

! DK 160170 B! DK 160170 B

Den foreliggende opfindelse angår en kredsløbsanordning til undertrykkelse af støjsignaler ved transmission af digitale signaler.The present invention relates to a circuitry for suppressing noise signals by transmitting digital signals.

Det er kendt at forstærke de af en modtager for sådanne sig-5 naler modtagne signaler i en forforstærker. De forstærkede amplituder bliver derpå lagret ved hjælp af et RC-led, så at der på dette danner sig en til amplituderne svarende analog værdi. De digitale signaler, som rager udover denne analoge værdi, udstyrer et efterfølgende forstærkertrin. Støjimpulser, som ligger under den lagrede 10 værdi, bliver derved undertrykt. Når nytteimpulsernes afstand er forskellig, skal tidskonstanten for RC-leddet være således bestemt, at signalerne med de korteste afstande stadig overføres. Dette medfører imidlertid, at den lagrede analoge værdi ved større impulsafstande af det digitale signal er nedsat så meget, at støjimpulser 15 lettere kommer igennem, f.eks. bliver digitale signaler med forskellige afstande, dvs. pulskodemodulerede signaler, anvendt ved fjernbetjening af radio- og fjernsynsapparater. De ved hjælp af infrarødt lys, som bærer udsendte signaler, består af flere serielle korte impulser, hvor informationen, dvs. hvilken kanal i fjernsyns-20 betjeningen, der skal påvirkes, ligger i de forskellige afstande mellem de enkelte impulser. På denne måde bliver der dannet digitale ord af flere bit, idet en stor afstand f.eks. danner et H-signal og en kort afstand et L-signal.It is known to amplify the signals received by a receiver for such signals in a preamplifier. The amplified amplitudes are then stored by means of an RC link so that an analogous value corresponding to the amplitudes is formed. The digital signals that extend beyond this analog value provide a subsequent amplifier stage. Noise pulses below the stored value are thereby suppressed. When the utility pulses are different, the time constant of the RC joint must be such that the signals with the shortest distances are still transmitted. However, this means that the stored analog value at larger pulse distances of the digital signal is reduced so much that noise pulses 15 more easily pass through, e.g. become digital signals with different distances, ie pulse code modulated signals used in remote control of radio and television sets. The infrared light, which carries the transmitted signals, consists of several serial short pulses, the information, ie. which channel of the television operation to be affected lies in the different distances between the individual pulses. In this way, digital words are formed by several bits, a large distance e.g. an H signal and a short distance form an L signal.

Ved de hidtil kendte kredsløbsudførelser med fjernstyring af 25 modtageapparater var enkeltvise støjimpulser ikke særlig kritiske, fordi prøvekredsløbene ikke akcepterede en fejlbehæftet modtaget ordre. Indenfor modtagerteknikken ser det anderledes ud, når denne er udstyret med mikroprocessorer, idet mikroprocessoren ved hjælp af sit program efter hinanden foretager de mest forskellige styringer 30 og overvågninger, som f.eks. aftastning af fjernstyringen, displayets visning, afstemning og frekvensregulering osv. Mikroprocessorsystemets program er opstillet således, at dette fortrinsberettiget behandler fjernstyringsordrerne. Det bliver i løbet af programmet igen og igen afprøvet, om der foreligger en fjernsty-35 ringsordre, og i modsat fald gennemløbes permanent andre underprogrammer. Når der nu forefindes stærke støjimpulser, bliver programmet løbende kaldt, så at mikroprocessorsystemet ikke kan opfylde andre opgaver.In the previously known circuit designs with remote control of 25 receiving devices, individual noise pulses were not very critical because the test circuits did not accept a faulty received order. Within the receiver technology, it looks different when it is equipped with microprocessors, the microprocessor, by means of its program, sequentially executing the most different controllers 30 and monitors, e.g. remote sensing, display display, tuning and frequency control, etc. The microprocessor system's program is set up so that it will process the remote control orders with preference. Over the course of the program, it is tested again and again whether a remote control order exists and, if not, other subprograms are permanently implemented. When strong noise impulses are present, the program is constantly called so that the microprocessor system cannot fulfill other tasks.

I DE-0S 29 43 913 beskrives en kredsløbsanordning, som tjener 2DE-0S 29 43 913 discloses a circuit device which serves 2

DK 160.170 BDK 160.170 B

til modtagelse af impulsformige lyssignaler ved hjælp af et opto-elektronisk omsætterorgan. Kredsløbsanordningen har til opgave at eliminere støjlysandele, navnlig i form af konstantlys og i afhængighed af konstantlysandelen at frembringe en variabel tærskel, så 5 at kun nytteimpulserne bliver evalueret. På indgangen af kredsløbet findes der herfor forskellige tidskonstantled, hvoraf det ene kun ved lavfrekvente signalandele frembringer en spænding, idet højere frekvente signaler kortsluttes af en kondensator. Det andet tidskonstantled danner for de lavfrekvente signalandele en kort-10 slutning, forholdet mellem de af tidskonstantleddene opdelte spændinger er frekvensafhængigt og ikke afhængigt af amplituden. Ved det j deri viste kredsløb bliver tærskelværdien i vid udstrækning bestemt af den lavfrekvent modulerede signal andel af den gennem modtagedioderne løbende strøm, men i kke af højden af signal ampi itu-15 den.for receiving pulsed light signals by means of an optoelectronic converter means. The purpose of the circuit device is to eliminate noise light proportions, in particular in the form of constant light and, depending on the constant light proportion, to produce a variable threshold so that only the utility pulses are evaluated. At the input of the circuit there are various time constant links for this purpose, one of which only generates a voltage at low frequency signals, shortening higher frequency signals by a capacitor. The second time constant conduit forms a short-circuit for the low frequency signals, the ratio of the voltages divided by the time constant conduits being frequency dependent and not dependent on the amplitude. In the circuit shown therein, the threshold value is largely determined by the low-frequency modulated signal proportion of the current flowing through the receiving diodes, but not by the height of the signal amplifier.

En tilsluttet komparator tjener som amplitudefilter med indstillelig komparatortærskel. Tærsklen bliver her afhængig af støjlysandelen.A connected comparator serves as an amplitude filter with adjustable comparator threshold. The threshold here becomes dependent on the noise light percentage.

Til undertrykkelse af støjimpulser er der blevet foreslået et 20 kredsløb (DE-PS 31 02 256), der undertrykker støjimpulserne såvel ved svage som ved stærke indgangssignaler. Dette kredsløb har i sin udgangskreds et trin, som ved større til det andet tidskonstantled førte indgangsamplituder ved hjælp af en zenerdiode fremkalder en begrænsning af udgangssignalet. Spændingen på udgangstrinnet kan 25 ikke stige udover denne begrænsede værdi, så at den resterende signalandel falder på det andet tidskonstantled, så at amplituden af signal niveauet på tidskonstantleddet bliver bestemt af amplituden af indgangsniveauet.For suppression of noise pulses, a 20 circuit (DE-PS 31 02 256) has been proposed which suppresses the noise pulses both at weak and at strong input signals. This circuit has in its output circuit a step which, at larger to the second time constant, causes input amplitudes by means of a zener diode to cause a limitation of the output signal. The voltage at the output stage cannot increase beyond this limited value so that the residual signal proportion falls on the second time constant, so that the amplitude of the signal level at the time constant is determined by the amplitude of the input level.

Formålet med den foreliggende opfindelse er at undgå denne 30 begrænsende effekt, så at det fulde indgangsniveausving overføres til udgangen. Dette opnås ved hjælp af kredsløbsanordningen med de i patentkravets kendetegnende del angivne kredsløbsforanstaltninger.The object of the present invention is to avoid this limiting effect so that the full input level swing is transmitted to the output. This is achieved by means of the circuit device with the circuit measures specified in the characterizing part of the patent claim.

Opfindelsen skal herefter forklares nærmere under henvisning til tegningen, hvor 35 fig. 1 viser en udførelsesform for kredsløbsanordningen ifølge opfindelsen og fig. 2 de ved de i fig. 1 angivne punkter fremkommende sig- . nal er.The invention will now be explained in more detail with reference to the drawing, in which FIG. 1 shows an embodiment of the circuit device according to the invention and FIG. 2 they are those of FIG. 1 points appearing. nal is.

En lysfølsom diode 1 er koblet i serie med en modstand 2 mellem 3 en stabiliseret driftsspændingskilde Ug og referencepotential. Forbindelsespunktet mellem dioden 1 og modstanden 2 er koblet til indgangen på et første forstærkertrin VI. De forstærkede signaler bliver ensrettet ved hjælp af en diode 3 og koblet til et første tids-5 konstantled, som består af modstande 4 og 5 og en kondensator 6. Signal spændingen føres over kondensatoren 6 i det første tidskonstantled til et af modstanden 5 og en kondensator 7 dannet andet tidskonstantled. Signal spændingen, som dannes på kondensatoren 7, er koblet til indgangen på et udgangstrin V2. Hvile-jævnspændingsni-10 veauet på basis i en transistor 8 i dette udgangstrin indstiller sig således, at den ikke falder under den med basis-emitterspændingen formindskede stabiliserede driftsspænding, med hvilken emitteren i transistoren 8 er forbundet. I kollektorkredsen for transistoren 8 ligger der en kollektormodstand, som Pull-Up-modstand 9, på hvilken 15 den for støjsignalerne befriede nyttesignal spænding kan udtages.A photosensitive diode 1 is connected in series with a resistor 2 between 3 a stabilized operating voltage source Ug and reference potential. The connection point between the diode 1 and the resistor 2 is coupled to the input of a first amplifier stage VI. The amplified signals are rectified by a diode 3 and coupled to a first time-constant 5 consisting of resistors 4 and 5 and a capacitor 6. The signal voltage is passed across the capacitor 6 in the first time constant to one of the resistor 5 and a capacitor 7 formed second time constant. The signal voltage generated on capacitor 7 is coupled to the input of an output stage V2. The DC voltage level at the base of a transistor 8 in this output stage adjusts so that it does not fall below the stabilized operating voltage diminished by the base-emitter voltage with which the emitter in the transistor 8 is connected. In the collector circuit of transistor 8 there is a collector resistor, such as Pull-Up resistor 9, on which the utility signal voltage released for the noise signals can be taken out.

I fig. 2A er de på udgangen af forstærkertrinnet VI liggende med støjimpulserne S behæftede nyttesignaler afbildet. Ved punktet B fås det i fig. 2B viste signal forløb. Spændingsforløbet ved punktet C er vist i fig. 2C. Det vil ses, at koblingstærsklen for udgangs-20 trinnet V2 lægges på et sådant niveau, at spidsværdierne af støj signalerne S ikke kan forspænde transistoren 8 i spærreretning. Først nyttesignalerne N kommer over den indtegnede koblingstærskel, som i det viste eksempel kan ligge mellem 4,3 volt og driftsspændingen Ug på 5 volt, nemlig efter omladning af det første 25 tidskonstantled 4,6. Umiddelbart efter at spændingen ved punktet C er faldet under denne koblingstærskel, kobler transistoren 8 igennem, så at niveauet på udgangen D kobles til højt potential. Hvilejævnspændingen i punktet C kan kredsløbsbetinget ikke falde under 4,3 volt. Tidskonstanten TI for det første tidskonstantled fås af 30 produktet af den af modstandene 4 og 5 dannede samlede modstand og værdien af kondensatoren 6. Da modstanden 5 imidlertid er meget lille i sammenligning med modstanden 4, bliver tidskonstanten TI praktisk taget TI = R4 x C6. Tidskonstanten T2 for det andet tidskonstantled bliver T2 = R5 X C7. Den skal dimensioneres således, 35 at den er mindre end den korteste impulsafstand i et ordreord i nyttesignalet. Tidskonstanten T2 skal vælges så stor, at niveauet i punktet B i kredsløbet ikke kan falde for meget mellem to ord i ordren.In FIG. 2A, the useful signals signaled at the output of the amplifier stage VI, with the noise pulses S, are depicted. At point B it is obtained in FIG. 2B. The voltage drop at point C is shown in FIG. 2C. It will be seen that the switching threshold for the output stage V2 is set at such a level that the peak values of the noise signals S cannot bias the transistor 8 in the blocking direction. First, the utility signals N are above the plotted switching threshold, which in the example shown can be between 4.3 volts and the operating voltage Ug of 5 volts, namely after recharging the first 25 time constant link 4.6. Immediately after the voltage at the point C has fallen below this switching threshold, the transistor 8 switches through so that the level of the output D is coupled to high potential. The resting DC voltage at point C, the circuit condition cannot fall below 4.3 volts. The time constant T1 for the first time constant link is obtained from the product of the total resistance formed by resistors 4 and 5 and the value of capacitor 6. However, since resistor 5 is very small in comparison with resistor 4, the time constant T1 becomes practically TI = R4 x C6. The time constant T2 for the second time constant becomes T2 = R5 X C7. It must be sized such that it is less than the shortest pulse distance in an order word in the utility signal. The time constant T2 must be chosen so large that the level at point B of the circuit cannot fall too much between two words in the order.

Ved hjælp af den beskrevne kredsløbsanordning undgås, atBy means of the described circuit device, it is avoided that

DK 160170 BDK 160170 B

4 nyttesignaler med større impulsvarighed, som ved tilstedeværelsen af et stabiliserende element parallelt med tidskonstanten T2 ville fremkalde en forøget ladning i lagerelementet 6, ikke kan undertrykkes, da belastningen af kredsløbet ved hjælp af udgangstrinnet 5 kun er virksom under impulspauserne, og følgelig er den under en impuls ind i lagerelementet 6 løbende ladning bestemt af tidskonstantleddet T2, Herved kan tidskonstanten T2 for det andet tidskonstantled vælges større, end dimensioneringsreglen efter den korteste impulsafstand foreskriver. På denne måde bliver udgangsim-10 pulserne gjort bredere, hvilket bidrager yderligere til støjundertrykkelsen.4 higher signal pulse duration signals which, in the presence of a stabilizing element parallel to the time constant T2, would produce an increased charge in the storage element 6, cannot be suppressed since the load of the circuit by means of the output stage 5 is only effective during the pulse breaks and consequently it is below an impulse into the storage element 6 continuous charge determined by the time constant link T2, Hereby the time constant T2 for the second time constant link can be chosen larger than the sizing rule according to the shortest pulse distance prescribes. In this way, the output pulses are made wider, which further contributes to the noise suppression.

15 20 25 30 3515 20 25 30 35

Claims (1)

DK 160170 B Patentkrav. Kredsløbsanordning til undertrykkelse af støjimpulser ved transmission af digitale signaler med forskellige tidsmæssige afstande og amplituder med flere tidskonstantled (4,5,6,7), hvor de 5 modtagne signaler føres til en forstærker (VI), til hvis udgang der er sluttet en ensretter (3), som kobler den ensrettede signal spænding over tidskonstantleddene til et udgangstrin, som indeholder mindst én transistor, og hvor tidskonstanten for det første tidskonstantled (4,5,6) dimensioneret efter nyttesignalernes (N) største 10 afstand er væsentligt større end det efter nyttesignalernes (N) korteste afstand dimensionerede andet tidskonstantled (5,7), kendetegnet ved, at tidskonstantleddet (5,7) med den mindste tidskonstant (T2) er koblet således til udgangstrinnet (V2), at det på tidskonstantleddet liggende hvilejævnspændingsniveau ikke 15 ligger under driftsspændingsniveauet formindsket med basis-emitter-spændingen på den med sin emitter til den stabiliserede driftsspændingskilde (Ug) sluttede transistor (8) i udgangstrinnet (V2), og at de for støjsignal erne befriede udgangssignaler er udtagelige på en i kollektorkredsen for transistoren (8) indkoblet modstand (9). 20 25 30 35DK 160170 B Patent claims. Circuit means for suppressing noise pulses by transmitting digital signals of different temporal distances and amplitudes with multiple time constant links (4,5,6,7), where the 5 received signals are fed to an amplifier (VI) to whose output a rectifier is connected (3) coupling the unidirectional signal voltage across the time constant links to an output stage containing at least one transistor, and wherein the time constant of the first time constant link (4,5,6) dimensioned by the greatest distance of the utility signals (N) is substantially greater than the after the shortest distance of the useful signals (N), the second time constant link (5.7) is dimensioned, characterized in that the time constant link (5.7) with the smallest time constant (T2) is coupled to the output stage (V2) so that the resting current level at the time constant link is not 15 is below the operating voltage level diminished by the base emitter voltage of it with its emitter to the stabilized operating voltage source (Ug) connected transistor (8) in the output stage (V2) and the output signals exempted from the noise signals are removable on a resistor (9) connected in the collector circuit for the transistor (8). 20 25 30 35
DK168184A 1983-03-26 1984-03-26 CIRCUIT DEVICE FOR COMPRESSION OF NOISE SIGNALS DK160170C (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3311069A DE3311069C1 (en) 1983-03-26 1983-03-26 Circuit arrangement for suppressing interference signals
DE3311069 1983-03-26

Publications (4)

Publication Number Publication Date
DK168184D0 DK168184D0 (en) 1984-03-26
DK168184A DK168184A (en) 1984-09-27
DK160170B true DK160170B (en) 1991-02-04
DK160170C DK160170C (en) 1991-07-01

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ID=6194749

Family Applications (1)

Application Number Title Priority Date Filing Date
DK168184A DK160170C (en) 1983-03-26 1984-03-26 CIRCUIT DEVICE FOR COMPRESSION OF NOISE SIGNALS

Country Status (6)

Country Link
EP (1) EP0120444B1 (en)
KR (1) KR910002767B1 (en)
AT (1) ATE36625T1 (en)
DE (1) DE3311069C1 (en)
DK (1) DK160170C (en)
ES (1) ES8501585A1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4343979C2 (en) * 1993-12-22 2001-03-22 Braehler Ics Konferenztechnik Infrared radiation receiver

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3028553A (en) * 1959-09-04 1962-04-03 Cutler Hammer Inc Voltage amplitude discriminating system having pulse width stretching means
US3599105A (en) * 1969-07-24 1971-08-10 Hughes Aircraft Co Amplitude discriminator with an adaptive threshold
DE2943913A1 (en) * 1979-10-31 1981-05-14 Sennheiser Electronic Kg, 3002 Wedemark Receiver for pulsed light signals of data transmission system - has opto-electronic converter feeding amplitude filter with threshold regulation
DE3102256C2 (en) * 1981-01-24 1982-10-21 Saba Gmbh, 7730 Villingen-Schwenningen Circuit arrangement for suppressing interference signals

Also Published As

Publication number Publication date
ES530964A0 (en) 1984-11-16
KR840008234A (en) 1984-12-13
DK168184D0 (en) 1984-03-26
ES8501585A1 (en) 1984-11-16
DE3311069C1 (en) 1984-05-30
DK160170C (en) 1991-07-01
EP0120444A2 (en) 1984-10-03
EP0120444A3 (en) 1986-02-19
KR910002767B1 (en) 1991-05-04
ATE36625T1 (en) 1988-09-15
EP0120444B1 (en) 1988-08-17
DK168184A (en) 1984-09-27

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