US3638183A
Expired / Lapsed
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Threshold value circuit
Assignee: Licentia Patent Verwaltungs GmbH
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Filing: 1970-03-09
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Granted: 1972-01-25
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Expires: 1990-03-09
Abstract
Abstract A threshold value circuit for a data transmission system in which at the receiver site the transmitted demodulated binary signals are fed to the threshold value circuit to produce an indication regarding errors in the character bits of the received character. The threshold circuit includes a pair of parallelly connected circuit paths having one end thereof connected to the source of signals and the other ends thereof connected to a comparator. One circuit path has a transfer function whose value is less than 1 while the other circuit path contains circuitry for storing and delaying the peak value of the received signal to provide a threshold level signal for the comparator; the value of the threshold level changing in accordance with changes in the level of the received signal which persists for a given time period.
Inventors
- 👤 Max Progler
- 👤 Klaus Wessenberg
- 👤 Winfried Wagner
- 👤 Horst Ohnsorge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:06
CPC Classifications
H; H04; H04L; H04L25/00; H04L25/02; H04L25/06; H04L25/061; H04L1/00; H04L1/20
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
168 words
In a data transmission system in which the signals are fed at the receiver site to threshold value circuits whose actuation or nonactuation represents the error decision for the character bits of the received character; said threshold value circuit comprising: first and second circuit paths connected between the input to said threshold circuit and the inputs of a comparator means, said comparator means emitting a characteristic output signal when the amplitudes of the input signals thereto deviate from one another by a given value; said first circuit path consisting of a network whose transfer function has a value less than 1; and said second circuit path including a half-wave rectifier connected in series with a circuit means having its output connected to one of the inputs of said comparator means for storing and delaying the peak value of the rectified signal, said circuit means changing the level of its output signal when a change in the level of the rectified signal has persisted for a given time period.
Claim 2
Dependent Claim
168 words
In a data transmission system in which the signals are fed at the receiver site to threshold value circuits whose actuation or nonactuation represents the error decision for the character bits of the received character; said threshold value circuit comprising: first and second circuit paths connected between the input to said threshold circuit and the inputs of a comparator means, said comparator means emitting a characteristic output signal when the amplitudes of the input signals thereto deviate from one another by a given value; said first circuit path consisting of a network whose transfer function has a value less than 1; and said second circuit path including a half-wave rectifier connected in series with a circuit means having its output connected to one of the inputs of said comparator means for storing and delaying the peak value of the rectified signal, said circuit means changing the level of its output signal when a change in the level of the rectified signal has persisted for a given time period.
Claim 3
Dependent Claim
33 words
The apparatus as defined in claim 1 wherein said circuit means only changes its output signal when the change in the level of the rectified signal has persisted for said given time period.
Claim 4
Dependent Claim
14 words
The apparatus defined in claim 2 wherein said circuit means is a low-pass filter.
Claim 5
Dependent Claim
15 words
The apparatus as defined in claim 1 wherein said network is an ohmic voltage divider.
Claim 6
Dependent Claim
22 words
The apparatus as defined in claim 1 wherein said network is a plurality of diodes connected in series in the forward direction.
Claim 7
Dependent Claim
19 words
The apparatus as defined in claim 1 wherein said network is a zener diode connected in the blocking direction.
Claim 8
Dependent Claim
14 words
The apparatus as defined in claim 1 wherein the half-wave rectifier comprises a diode.
Claim 9
Dependent Claim
63 words
The apparatus as defined in claim 3 wherein said threshold circuit includes third and fourth circuit paths having their outputs connected to the inputs of a second comparator means, said third and fourth circuit paths corresponding structurally to said first and second circuit paths respectively, the half-wave rectifier of said fourth circuit path being oppositely poled from that of said second circuit path.
Claim 10
Dependent Claim
30 words
The apparatus as defined in claim 3 including switch means for feeding the transmitted signals to said threshold circuit only at the moment of the center of the transmitted signal.
Claim 11
Dependent Claim
27 words
The apparatus as defined in claim 3 including impedance transformer means connected between the output of said low-pass filter and the respective input of said comparator means.
Claim 12
Dependent Claim
16 words
The apparatus as defined in claim 10 wherein said impedance transformer comprises a field effect transistor.
Claim 13
Dependent Claim
19 words
The apparatus as defined in claim 11 wherein the drain resistor of the field effect transistor is a potentiometer.
Claim 14
Dependent Claim
19 words
The apparatus as defined in claim 10 wherein said impedance transformer is a transistor connected as an emitter follower.
Claim 15
Dependent Claim
17 words
The apparatus as defined in claim 13 wherein the emitter resistance of said transistor is a potentiometer.
Claim 16
Dependent Claim
19 words
The apparatus as defined in claim 3 wherein the low-pass filter is an RC network having adjustable ohmic resistors.
Claim 17
Dependent Claim
26 words
The apparatus as defined in claim 10 further comprising a limiter circuit including two antiparallel connected biased diodes connected to the output of said low-pass filter.
Claim 18
Dependent Claim
88 words
The apparatus as defined in claim 1 wherein said circuit means comprises first and second memory means, said first memory means being connected to the output of said half-wave rectifier for storing the peak value of said transmitted signal and said second memory means being connected to the input of said comparator means for storing the threshold value; and means for periodically connecting said first and second memory means to change the value stored in said second memory means to that instantaneously stored in said first memory means.
Claim 19
Dependent Claim
36 words
The apparatus as defined in claim 17 wherein each of said first and second memory means includes a memory capacitor and wherein said means for periodically connecting said first and second memory means includes a switch.
Claim 20
Dependent Claim
73 words
The apparatus as defined in claim 18 wherein said circuit means further includes an error detecting means responsive to said characteristic output signal from said comparator means for emitting an output pulse each time said characteristic output signal appears, and means responsive to said output pulses for maintaining said switch in an open position so that a shift of the erroneous value stored in said first memory to said second memory is prevented.
Claim 21
Dependent Claim
88 words
The apparatus as defined in claim 19 wherein said circuit means further includes an integrating means for emitting an output pulse whenever the integrated value of the output pulses from said error detecting means for a said given time period exceeds a given value, and means responsive to the output pulse from said integrating means for immediately closing said switch to transfer the contents of said first memory to said second memory and for subsequently causing said first memory to be reset for a short period of time.
Claim 22
Dependent Claim
194 words
The apparatus as defined in claim 18 wherein said circuit means includes: trigger circuit for producing an output pulse whenever said comparator mEans produces said characteristic output signal; an OR gate, the output signal of which controls the opening and closing of said switch, one input of said OR gate being connected to the output of a clock pulse generator, and the other input thereof being connected to the output of said trigger circuit via a normally closed switch; a normally open switch connected between the output of said first memory means and ground, and means, including a differentiator, responsive to the output signals from said clock pulse generator for momentarily closing said normally open switch at the end of each clock pulse to discharge the capacitor of said first memory; an integrating means for integrating the output pulses from said trigger circuit and producing an output signal whenever the value of the integral for a given period of time exceeds a given value; and means responsive to the output signals from said integrating means for opening said normally closed switch and for immediately causing said clock pulse generator to emit a clock pulse.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-24 | 1975-07-26 | 1976-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-24 | 1979-07-26 | 1980-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-24 | 1983-07-26 | 1984-01-25 | $7700.00 | Window Closed / Lapsed |