US4140914A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Isolated signal conditioner
Assignee: Applied Automation Inc
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Filing: 1977-12-23
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Granted: 1979-02-20
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Expires: 1997-12-23
Abstract
Abstract An isolated signal conditioning circuit is provided whereby control or measurement circuitry is isolated from a load, such as a control instrument, through the use of optical isolation and a switching relay. Optical isolation is utilized to isolate the input signal produced by the control or measurement circuitry, from the load. The switching relay isolates a feedback circuit utilized to insure that the signal supplied to the load is an accurate representation of the input signal produced by the control or measurement circuitry.
Inventors
- 👤 William R. Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 10:34
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/04; H03F3/08; H03F3/087; G; G11; G11C; G11C27/00; G11C27/02; G11C27/024; G11C27/026
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
278 words
Apparatus comprising: an optical isolation means; means for supplying a first electrical signal to the input of said optical isolation means; current amplification means; means for supplying a second electrical signal, which is representative of said first electrical signal, from the output of said optical isolation means to the input of said current amplification means; a resistor; means for supplying said second electrical signal, which has been amplified from the output of said current amplification means to said resistor; a capacitor; a sample and hold means; means for connecting said capacitor across said resistor in such a manner that said capacitor will be charged to the voltage, across said resistor, produced by said second electrical signal which has been amplified; means for switching said capacitor, when it is charged to the voltage across said resistor, to the input of said sample-and-hold means in such a manner that said capacitor can never be connected across said resistor and to the input of said sample-and-hold means at the same time; and means for supplying a third electrical signal, which is representative of said second electrical signal, which has been amplified from the output of said sample-and-hold means to said means for supplying a first electrical signal to the input of said optical isolation means in such a manner that, if said second electrical signal which has been amplified is not a correct representation of said first electrical signal, the input to said optical isolation means will be varied to force said second electrical signal to a new value which will cause said second electrical signal, which has been amplified to be a more accurate representation of said first electrical signal.
Claim 2
Dependent Claim
278 words
Apparatus comprising: an optical isolation means; means for supplying a first electrical signal to the input of said optical isolation means; current amplification means; means for supplying a second electrical signal, which is representative of said first electrical signal, from the output of said optical isolation means to the input of said current amplification means; a resistor; means for supplying said second electrical signal, which has been amplified from the output of said current amplification means to said resistor; a capacitor; a sample and hold means; means for connecting said capacitor across said resistor in such a manner that said capacitor will be charged to the voltage, across said resistor, produced by said second electrical signal which has been amplified; means for switching said capacitor, when it is charged to the voltage across said resistor, to the input of said sample-and-hold means in such a manner that said capacitor can never be connected across said resistor and to the input of said sample-and-hold means at the same time; and means for supplying a third electrical signal, which is representative of said second electrical signal, which has been amplified from the output of said sample-and-hold means to said means for supplying a first electrical signal to the input of said optical isolation means in such a manner that, if said second electrical signal which has been amplified is not a correct representation of said first electrical signal, the input to said optical isolation means will be varied to force said second electrical signal to a new value which will cause said second electrical signal, which has been amplified to be a more accurate representation of said first electrical signal.
Claim 3
Dependent Claim
35 words
Apparatus in accordance with claim 1 additionally comprising: a diode bridge; a load; and means for supplying said second electrical signal, which has been amplified through said resistor and said diode bridge to said load.
Claim 4
Dependent Claim
184 words
Apparatus in accordance with claim 1 additionally comprising: means for generating a periodically pulsating fourth electrical signal having a period T 1 ; means for supplying said fourth electrical signal to said means for switching said capacitor to control the switching operation; means for generating a periodically pulsating fifth electrical signal having a period T 2 , in response to said fourth electrical signal; means for generating a periodically pulsating sixth electrical signal having a period T 3 , in response to said fifth electrical signal, in such a manner that said sixth electrical signal is delayed with respect to said fourth electrical signal by a time given by said period T 2 ; and means for supplying said sixth electrical signal to said sample-and-hold means in such a manner that said sample-and-hold means is placed in a sample mode for said period T 3 , after said capacitor has been switched to the input of said sample-and-hold means, and is returned to a hold mode at the end of said period T 3 , before said capacitor is switched back across said resistor.
Claim 5
Independent Claim
253 words
A method for providing isolation between electrical circuits comprising the steps of: supplying a first electrical signal to the input of an optical isolation means; supplying a second electrical signal which is representative of said first electrical signal from the output of said optical isolation means to the input of a current amplification means; supplying the second electrical signal, which has been amplified from the output of said current amplification means to a resistor; connecting a capacitor across said resistor in such a manner that said capacitor will be charged to the voltage, across said resistor, produced by said second electrical signal which has been amplified; switching said capacitor, when it is charged to the voltage across said resistor, to the input of a sample-and-hold means in such a manner that said capacitor can never be connected across said resistor and to the input of said sample-and-hold means at the same time; and supplying a third electrical signal, which is representative of said second electrical signal which has been amplified, from the output of said sample-and-hold means; said combining said first electrical signal and said third electrical signal in such a manner that, if said second signal which has been amplified is not a correct representation of said first electrical signal, the input to said optical isolation means will be varied to force said second electrical signal to a new value which will cause said second electrical signal which has been amplified to be a more accurate representation of said first electrical signal.
Claim 6
Independent Claim
253 words
A method for providing isolation between electrical circuits comprising the steps of: supplying a first electrical signal to the input of an optical isolation means; supplying a second electrical signal which is representative of said first electrical signal from the output of said optical isolation means to the input of a current amplification means; supplying the second electrical signal, which has been amplified from the output of said current amplification means to a resistor; connecting a capacitor across said resistor in such a manner that said capacitor will be charged to the voltage, across said resistor, produced by said second electrical signal which has been amplified; switching said capacitor, when it is charged to the voltage across said resistor, to the input of a sample-and-hold means in such a manner that said capacitor can never be connected across said resistor and to the input of said sample-and-hold means at the same time; and supplying a third electrical signal, which is representative of said second electrical signal which has been amplified, from the output of said sample-and-hold means; said combining said first electrical signal and said third electrical signal in such a manner that, if said second signal which has been amplified is not a correct representation of said first electrical signal, the input to said optical isolation means will be varied to force said second electrical signal to a new value which will cause said second electrical signal which has been amplified to be a more accurate representation of said first electrical signal.
Claim 7
Dependent Claim
31 words
A method in accordance with claim 4 comprising the additional step of supplying said second electrical signal which has been amplified through said resistor and a diode bridge to a load.
Claim 8
Dependent Claim
183 words
A method in accordance with claim 4 comprising the additional steps of: producing a periodically pulsating fourth electrical signal having a period T 1 ; utilizing said fourth electrical signal to control the switching of said capacitor from across said resistor to the input of said sample-and-hold means; producing a periodically pulsating fifth electrical signal having a period T 2 in response to said fourth electrical signal; producing a periodically pulsating sixth electrical signal having a period T 3 , in response to said fifth electrical signal, in such a manner that said sixth electrical signal is delayed with respect to said fourth electrical signal by a time given by said period T 2 ; and supplying said sixth electrical signal to said sample-and-hold means in such a manner that said sample-and-hold means is placed in a sample mode for said period T 3 , after said capacitor has been switched to the input of said sample-and-hold means, and is returned to a hold mode at the end of said period T 3 , before said capacitor is switched back across said resistor.
Claim 9
Independent Claim
144 words
A method for providing isolation between electrical circuits comprising the steps of: producing a light beam in response to a first electrical signal; producing, in response to said light beam, a second electrical signal which is representative of said first electrical signal; amplifying said second electrical signal to produce a third electrical signal; intermittently sampling said third electrical signal, to produce a fourth electrical signal which is representative of said third electrical signal, in such a manner that said third electrical signal is electrically isolated from said fourth electrical signal; and utilizing said fourth electrical signal to vary the intensity of said light beam, if said third electrical signal is not a correct representation of said first signal, in such a manner that said third electrical signal will assume a new value which will be a more accurate representation of said first electrical signal.
Claim 10
Independent Claim
144 words
A method for providing isolation between electrical circuits comprising the steps of: producing a light beam in response to a first electrical signal; producing, in response to said light beam, a second electrical signal which is representative of said first electrical signal; amplifying said second electrical signal to produce a third electrical signal; intermittently sampling said third electrical signal, to produce a fourth electrical signal which is representative of said third electrical signal, in such a manner that said third electrical signal is electrically isolated from said fourth electrical signal; and utilizing said fourth electrical signal to vary the intensity of said light beam, if said third electrical signal is not a correct representation of said first signal, in such a manner that said third electrical signal will assume a new value which will be a more accurate representation of said first electrical signal.
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) | 1982-02-19 | 1982-08-21 | 1983-02-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-02-19 | 1986-08-21 | 1987-02-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-02-19 | 1990-08-21 | 1991-02-20 | $7700.00 | Window Closed / Lapsed |