Patent US3600604A successfully refreshed from Google Patents.
US3600604A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Failsafe logic gates
Assignee: Westinghouse Electric Corp
•
Filing: 1968-12-03
•
Granted: 1971-08-17
•
Expires: 1988-12-03
Abstract
Abstract A novel electronic switching circuit is operated as an AC enable gate circuit which is adaptable to perform diverse functions in which failsafeness is desired. These functions include logic gating in binary data signal systems and interlocking relay functions in safety monitoring systems. The switching circuit construction yields an enable gate circuit operation mode which relies upon two dynamic signals to thereby provide virtually total failsafeness. The gate switching is performed by actuating an active amplifying device between its ENERGIZED and DEENERGIZED states to provide the OPEN and CLOSED enable gate circuit conditions, respectively. A gate actuation signal input network of the circuit derives the device energizing signal in response to a dynamic actuation signal, which is one of the dynamic signals relied upon for failsafe properties. The enable gate channel of the circuit is of a construction which passes only a dynamic, or AC carrier signal above a predetermined threshold. The carrier signal is the other of the dynamic signals relied upon for failsafe properties. The AC carrier is amplified and then attenuated in its passage through the enable gate channel to cooperate with a thresholding in other circuits which may be connected in cascade.
Inventors
- 👤 George M Thorne-Booth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:59
CPC Classifications
B; B61; B61L; B61L3/00; B61L3/16; B61L3/18; B61L3/185; H; H03; H03F; H03F3/00; H03F3/72; H03K; H03K19/00; H03K19/007; B60; B60L; B60L2200/00; B60L2200/26
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
303 words
An exclusive OR type logical gate switch network having two dynamic signal gate channels comprising a restrictive channel and a nonrestrictive channel, said gate switch network being actuable to an OPEN GATE condition of the restrictive gate channel in response to a predetermined signal state of a gate actuation signal, said predetermined signal state including presence of a pRedetermined dynamic signal state of the gate actuation signal, said logical gate switch network being in an OPEN GATE condition of the nonrestrictive gate channel in absence of the predetermined signal state of the gate actuation signal, said logical gate switch network comprising; a nonrestrictive gate channel switch means including an active amplification device which is energizable to an OPEN GATE condition in which it passes a dynamic signal in response to a power-switching DC signal of a first of opposite polarities, a restrictive gate channel switch means including an active amplification device which is energizable to an OPEN GATE condition in which it passes a dynamic signal in response to a power-switching DC signal of a second of opposite polarities, a common active amplification device power supply busline operatively connected to both the nonrestrictive and the restrictive gate channel switch means, a continuous signal source means for applying a first powerswitching DC signal of said first polarity and of a first predetermined magnitude to the power supply busline, and a unidirectional charge path capacitor circuit means for receiving said gate actuation signal and when said predetermined signal state of the gate actuation signal is present said unidirectional charge path capacitor circuit means being operative to apply a second DC signal of the second polarity and of a magnitude greater than said first predetermined magnitude to the common busline in bucking relationship to the first DC signal to energize the restrictive gate channel switching means.
Claim 2
Dependent Claim
303 words
An exclusive OR type logical gate switch network having two dynamic signal gate channels comprising a restrictive channel and a nonrestrictive channel, said gate switch network being actuable to an OPEN GATE condition of the restrictive gate channel in response to a predetermined signal state of a gate actuation signal, said predetermined signal state including presence of a pRedetermined dynamic signal state of the gate actuation signal, said logical gate switch network being in an OPEN GATE condition of the nonrestrictive gate channel in absence of the predetermined signal state of the gate actuation signal, said logical gate switch network comprising; a nonrestrictive gate channel switch means including an active amplification device which is energizable to an OPEN GATE condition in which it passes a dynamic signal in response to a power-switching DC signal of a first of opposite polarities, a restrictive gate channel switch means including an active amplification device which is energizable to an OPEN GATE condition in which it passes a dynamic signal in response to a power-switching DC signal of a second of opposite polarities, a common active amplification device power supply busline operatively connected to both the nonrestrictive and the restrictive gate channel switch means, a continuous signal source means for applying a first powerswitching DC signal of said first polarity and of a first predetermined magnitude to the power supply busline, and a unidirectional charge path capacitor circuit means for receiving said gate actuation signal and when said predetermined signal state of the gate actuation signal is present said unidirectional charge path capacitor circuit means being operative to apply a second DC signal of the second polarity and of a magnitude greater than said first predetermined magnitude to the common busline in bucking relationship to the first DC signal to energize the restrictive gate channel switching means.
Claim 3
Dependent Claim
42 words
A gate switch network in accordance with claim 1 for use with a gate actuation signal wherein the predetermined signal state comprises a signal wave alternating about a signal ground, with; said unidirectional charge path capacitor circuit means being a rectifier circuit.
Claim 4
Dependent Claim
128 words
Signal switching apparatus comprising: switch means responsive to a switching signal applied to a first input for permitting an input signal applied to a second input to provide an output signal; signal means for providing a first signal having first and second signal states; means operative with said switch means and said signal means for applying said switching signal to said first input of said switch means in response to said first signal being in said first state for less than a predetermined time duration and for removing said switching signal from said first input of said switch means in response to one of said first signal being in said second signal state and said first signal state for a time duration greater than said predetermined time duration.
Claim 5
Dependent Claim
128 words
Signal switching apparatus comprising: switch means responsive to a switching signal applied to a first input for permitting an input signal applied to a second input to provide an output signal; signal means for providing a first signal having first and second signal states; means operative with said switch means and said signal means for applying said switching signal to said first input of said switch means in response to said first signal being in said first state for less than a predetermined time duration and for removing said switching signal from said first input of said switch means in response to one of said first signal being in said second signal state and said first signal state for a time duration greater than said predetermined time duration.
Claim 6
Dependent Claim
157 words
Signal switching apparatus comprising: switch means responsive to a first signal applied to a first input and a second signal applied to a second input, with second signal enabling said switch means to provide an output signal indication upon the occurrence of said first signal; signal means for providing a third signal comprising a first signal state, having at least a predetermined time duration, and a second signal state; means operative with said switch means and said signal means for applying said second signal to the second input of said switch means in response to said third signal being in said first signal state for enabling said switch means, and for removing said second signal from the second input of said switch means in response to said third signal being in one of said second signal state or said first signal state for a time duration longer than said predetermined time duration, for disabling said switch means.
Claim 7
Dependent Claim
157 words
Signal switching apparatus comprising: switch means responsive to a first signal applied to a first input and a second signal applied to a second input, with second signal enabling said switch means to provide an output signal indication upon the occurrence of said first signal; signal means for providing a third signal comprising a first signal state, having at least a predetermined time duration, and a second signal state; means operative with said switch means and said signal means for applying said second signal to the second input of said switch means in response to said third signal being in said first signal state for enabling said switch means, and for removing said second signal from the second input of said switch means in response to said third signal being in one of said second signal state or said first signal state for a time duration longer than said predetermined time duration, for disabling said switch means.
Claim 8
Dependent Claim
121 words
Signal switching apparatus comprising: switch means responsive to a switching signal applied to a first input for permitting an input signal applied to a second input to provide an output signal; signal means for producing a first signal coded to have a predetermined frequency; and means operative with said switch means and said signal means For applying said switching signal to said first input of said switch in response to said first signal being produced by said signal means and for removing said switching signal from said first input of said switch in response to one of said signal means no longer producing said first signal or said signal means producing another signal having a frequency different than said first signal.
Claim 9
Dependent Claim
121 words
Signal switching apparatus comprising: switch means responsive to a switching signal applied to a first input for permitting an input signal applied to a second input to provide an output signal; signal means for producing a first signal coded to have a predetermined frequency; and means operative with said switch means and said signal means For applying said switching signal to said first input of said switch in response to said first signal being produced by said signal means and for removing said switching signal from said first input of said switch in response to one of said signal means no longer producing said first signal or said signal means producing another signal having a frequency different than said first signal.
Claim 10
Dependent Claim
127 words
Signal gating apparatus comprising: a switch responsive to a control signal applied to a control input for permitting an input signal to provide an output signal; signal means for providing a periodic signal of period T, which traverses between first and second levels; and means operative with said switch and said signal means for applying said control signal to said control input of said switch in response to said first level of said periodic signal during each period T, and for removing said control signal from said control input of said switch in response to one of said second level of said periodic signal during each period T and said first level for a predetermined interval of time which is longer in duration than said period T.
Claim 11
Dependent Claim
127 words
Signal gating apparatus comprising: a switch responsive to a control signal applied to a control input for permitting an input signal to provide an output signal; signal means for providing a periodic signal of period T, which traverses between first and second levels; and means operative with said switch and said signal means for applying said control signal to said control input of said switch in response to said first level of said periodic signal during each period T, and for removing said control signal from said control input of said switch in response to one of said second level of said periodic signal during each period T and said first level for a predetermined interval of time which is longer in duration than said period T.
Claim 12
Dependent Claim
199 words
A failsafe circuit for gating a dynamic carrier signal, said circuit being actuable to provide an OPEN GATE condition in response to a predetermined signal state of a gate actuation signal, said circuit comprising: an active amplifying device having a first control electrode and second and third operating potential electrodes, said amplifying device being operative only during application of a predetermined operating potential across the second and third electrodes, a first input network for receiving said gate actuation signal, said first input network including a first circuit means responsive to presence of the predetermined signal state to produce the predetermined operating potential and for applying same across the second and third electrodes, a second input network for receiving the dynamic carrier signal and coupling same to said first electrode of the amplifying device, said second input network including a DC blocking means, and a dynamic carrier signal output network operatively connected in a current circuit path through said second and third electrodes, said output network including a stepdown transformer, said stepdown transformer cooperating with the gain of the active amplification device to provide a predetermined signal attenuation to yield a net gate circuit signal gain substantially equal to unity.
Claim 13
Dependent Claim
199 words
A failsafe circuit for gating a dynamic carrier signal, said circuit being actuable to provide an OPEN GATE condition in response to a predetermined signal state of a gate actuation signal, said circuit comprising: an active amplifying device having a first control electrode and second and third operating potential electrodes, said amplifying device being operative only during application of a predetermined operating potential across the second and third electrodes, a first input network for receiving said gate actuation signal, said first input network including a first circuit means responsive to presence of the predetermined signal state to produce the predetermined operating potential and for applying same across the second and third electrodes, a second input network for receiving the dynamic carrier signal and coupling same to said first electrode of the amplifying device, said second input network including a DC blocking means, and a dynamic carrier signal output network operatively connected in a current circuit path through said second and third electrodes, said output network including a stepdown transformer, said stepdown transformer cooperating with the gain of the active amplification device to provide a predetermined signal attenuation to yield a net gate circuit signal gain substantially equal to unity.
Claim 14
Dependent Claim
100 words
A gate circuit in accordance with claim 7, for use in gating a dynamic carrier signal having a waveform consisting of a periodically repeated pulse signal with a predetermined pulse width, with; said active amplification device being a transistor with the output network operatively connected in a current circuit path through the emitter and collector electrodes, said second input network including a second circuit means operative to ON-BIAS the transistor between pulses and to CUT-OFF the transistor during presence of a pulse, the primary winding of the stepdown transformer being adapted to exhibit self-ring properties coincident with the CUT-OFF pulse.
Claim 15
Dependent Claim
65 words
A gate circuit in accordance with claim 7, for use in gating a periodically varying dynamic carrier signal having a predetermined frequency, with; said output network including a parallel tuned circuit having a resonant frequency equal to said predetermined frequency, said parallel tuned circuit comprising the primary of said stepdown transformer and a capacitor means operatively associated with the primary winding in shunt relationship thereacross.
Claim 16
Dependent Claim
256 words
A failsafe circuit for gating a dynamic carrier signal, said circuit being actuable to provide an OPEN GATE condition in response to a predetermined signal state of a periodic gate actuation signal of period T, said circuit comprising: an active amplifying device having a first control electrode and second and third operating potential eLectrodes, said amplifying device being operative only during application of a predetermined operating potential across the second and third electrodes; a first input network for receiving said gate actuation signal, said first input network including a first circuit means responsive to presence of the predetermined signal state during each said period T to produce the predetermined operating potential and for applying same across the second and third electrodes, said first input network including means responsive to the presence of the predetermined signal state for a predetermined interval of time, which is greater than said period T, for removing the predetermined operating potential from across the second and third electrodes; a second input network for receiving the dynamic carrier signal and coupling same to said first electrode of the amplifying device, said second input network including a DC blocking means; and a dynamic carrier signal output network operatively connected in a current circuit path through said second and third electrodes, said output network including a passive attenuation and DC blocking means, said attenuation and DC blocking means cooperating with the gain of the active amplification device to provide a predetermined signal attenuation to yield a net gate circuit signal gain substantially equal to unity.
Claim 17
Dependent Claim
256 words
A failsafe circuit for gating a dynamic carrier signal, said circuit being actuable to provide an OPEN GATE condition in response to a predetermined signal state of a periodic gate actuation signal of period T, said circuit comprising: an active amplifying device having a first control electrode and second and third operating potential eLectrodes, said amplifying device being operative only during application of a predetermined operating potential across the second and third electrodes; a first input network for receiving said gate actuation signal, said first input network including a first circuit means responsive to presence of the predetermined signal state during each said period T to produce the predetermined operating potential and for applying same across the second and third electrodes, said first input network including means responsive to the presence of the predetermined signal state for a predetermined interval of time, which is greater than said period T, for removing the predetermined operating potential from across the second and third electrodes; a second input network for receiving the dynamic carrier signal and coupling same to said first electrode of the amplifying device, said second input network including a DC blocking means; and a dynamic carrier signal output network operatively connected in a current circuit path through said second and third electrodes, said output network including a passive attenuation and DC blocking means, said attenuation and DC blocking means cooperating with the gain of the active amplification device to provide a predetermined signal attenuation to yield a net gate circuit signal gain substantially equal to unity.
Claim 18
Dependent Claim
72 words
A gate circuit in accordance with claim 10, wherein said predetermined signal state of the gate actuation signal includes presence of a predetermined dynamic signal state; with said first input network comprising a unidirectional charge path capacitor circuit means operative to charge a storage capacitor when a gate actuation signal having said predetermined dynamic signal state is applied thereto, said storage capacitor being operative as the source of the predetermined operating potential.
Claim 19
Dependent Claim
30 words
A gate circuit in accordance with claim 1, with; means for blocking propagation of a received dynamic carrier signal through the circuit unless it exceeds a predetermined minimum signal level.
Claim 20
Dependent Claim
43 words
A gate circuit in accordance with claim 12, for use in gating a periodically varying dynamic carrier signal having a predetermined frequency, with; said dynamic carrier signal output network including a parallel tuned circuit having a resonant frequency equal to said predetermined frequency.
Claim 21
Dependent Claim
62 words
A gate circuit in accordance with claim 12, with; said active amplification device being a transistor with said second input network in coupling relationship to its base, said means for blocking propagation including a third circuit means operative to allow the dynamic carrier signal to pass only if same exceeds the minimum forward conducting voltage across the base-emitter junction of the transistor.
Claim 22
Dependent Claim
97 words
A gate circuit in accordance with claim 14, for use in gating a dynamic carrier signal having a waveform comprising a periodically repeated pulse signal with a predetermined pulse width, with; said third circuit means comprising an ON-BIAS capacitor having an input terminal and having another terminal, said another terminal being connected to signal ground through a unidirectional current device to level shift the input waveform to provide a shifted waveform at the base, said shifted waveform having the portion of the wave between pulses of a sufficient amplitude level, to exceed said minimum forward conducting voltage.
References Cited (Backward Citations)
US2519763A
Cited
US2649543A
Cited
US2752530A
Cited
US2946957A
Cited
US2987627A
Cited
US3005160A
Cited
US3062973A
Cited
US3421018A
Cited
US3430066A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-08-16 | 1975-02-15 | 1975-08-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-16 | 1979-02-15 | 1979-08-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-16 | 1983-02-15 | 1983-08-17 | $7700.00 | Window Closed / Lapsed |