US5034681A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Voltage detection
Assignee: Siemens Mobility Ltd
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Filing: 1989-12-06
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Granted: 1991-07-23
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Expires: 2009-12-06
Abstract
Abstract A circuit arrangement for detecting an input voltage comprises an oscillator responsive to the voltage, the oscillator including a pair of transistors (8, 9) connected as an astable multivibrator, each of the transistors having a load which comprises a primary winding (16 or 17) of a current transformer (T) and a low resistance proof resistor (12 or 13). A current flows through a secondary winding (18) of the transformer the amplitude of which current is proportional to the input voltage.
Inventors
- 👤 Malcolm R. Reeves
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:22
CPC Classifications
B; B61; B61L; B61L1/00; B61L1/20; G; G01; G01R; G01R19/00; G01R19/145; G01R19/155
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
168 words
A circuit arrangement for detecting a voltage at an input and producing at an output a current dependent on the voltage, the arrangement comprising: an oscillator responsive to the voltage, the oscillator including at least one transistor having a load which comprises an impedance and a primary winding of a transformer, wherein said impedance is a low impedance proof impedance and said transformer is a current transformer, the current flowing through a secondary winding of the transformer and the output being isolated from the input by the transformer; an operational amplifier being connected with the secondary winding of the current transformer, the amplifier having a first, high output level if the said voltage is of a first value, and a second, low output level if the said voltage is of a second, low value; and opposite ends of said secondary winding being connected with a first input of the operational amplifier and a center tap of the secondary winding being connected with another input of the operational amplifier.
Claim 2
Dependent Claim
168 words
A circuit arrangement for detecting a voltage at an input and producing at an output a current dependent on the voltage, the arrangement comprising: an oscillator responsive to the voltage, the oscillator including at least one transistor having a load which comprises an impedance and a primary winding of a transformer, wherein said impedance is a low impedance proof impedance and said transformer is a current transformer, the current flowing through a secondary winding of the transformer and the output being isolated from the input by the transformer; an operational amplifier being connected with the secondary winding of the current transformer, the amplifier having a first, high output level if the said voltage is of a first value, and a second, low output level if the said voltage is of a second, low value; and opposite ends of said secondary winding being connected with a first input of the operational amplifier and a center tap of the secondary winding being connected with another input of the operational amplifier.
Claim 3
Dependent Claim
64 words
An arrangement according to claim 1, wherein the oscillator comprises first and second transistors connected as an astable multivibrator, the load of the first transistor comprising a first primary winding of the current transformer and a first low impedance proof impedance and the load of the second transistor comprising a second primary winding of the current transformer and a second low impedance proof impedance.
Claim 4
Dependent Claim
20 words
An arrangement according to claim 1, wherein the or each low impedance proof impedance is a low resistance proof resistor.
Claim 5
Dependent Claim
40 words
An arrangement according to claim 1, wherein a filter network including a resistor and a capacitor is provided for filtering an alternating current component in the said voltage, the said resistor of the network being a low resistance proof resistor.
Claim 6
Dependent Claim
22 words
A circuit arrangement according to claim 1, in an interlocking system for use in controlling a controlled element of a railway system.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-07-22 | 1995-01-21 | 1995-07-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-07-22 | 1999-01-21 | 1999-07-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-07-22 | 2003-01-21 | 2003-07-23 | $7700.00 | Window Closed / Lapsed |