US4403183A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Active voltage probe
Assignee: Tektronix Inc
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Filing: 1981-04-10
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Granted: 1983-09-06
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Expires: 2001-04-10
Abstract
Abstract An active voltage probe receiving a DC power voltage via an outer conductor of a coaxial cable is disclosed. The probe includes a differential amplifier with inputs connected to input and reference terminals via DC paths and a follower amplifier with an input connected to the input terminal via an AC path. Outputs currents from the differential and follower amplifiers are applied to an inner conductor of the coaxial cable.
Inventors
- 👤 Jonathan C. Lueker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 05:32
CPC Classifications
G; G01; G01R; G01R13/00; G01R13/20; G01R13/22; G01R19/00; G01R19/145; G01R19/155
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
113 words
An active voltage probe, comprising: a probe head including a differential amplifier with inputs connected to input and reference terminals through DC paths, and follower amplifier means with an input connected to said input terminal through an AC path; a coaxial cable including an inner conductor for transmitting output currents from said differential amplifier and said follower amplifier means, and an outer conductor for applying a DC power voltage to said differential amplifier and said follower amplifier means; and an output circuit connected to the opposite end of said coaxial cable, wherein said outer conductor is connected to a DC power voltage source and said inner conductor is connected to a termination resistor.
Claim 2
Dependent Claim
113 words
An active voltage probe, comprising: a probe head including a differential amplifier with inputs connected to input and reference terminals through DC paths, and follower amplifier means with an input connected to said input terminal through an AC path; a coaxial cable including an inner conductor for transmitting output currents from said differential amplifier and said follower amplifier means, and an outer conductor for applying a DC power voltage to said differential amplifier and said follower amplifier means; and an output circuit connected to the opposite end of said coaxial cable, wherein said outer conductor is connected to a DC power voltage source and said inner conductor is connected to a termination resistor.
Claim 3
Dependent Claim
26 words
An active voltage probe according to claim 1 wherein the output from said differential amplifier is applied to the input end of said follower amplifier means.
Claim 4
Dependent Claim
23 words
An active voltage probe according to claim 1 wherein said differential amplifier and said follower amplifier means are implemented as a hybrid circuit.
Claim 5
Dependent Claim
28 words
An active voltage probe according to claim 1 wherein the other end of said termination resistor receives a bias voltage to cancel bias currents from said probe head.
Claim 6
Dependent Claim
22 words
An active voltage probe according to claim 1 wherein said coaxial cable is connected to said output circuit via a coaxial connector.
Claim 7
Dependent Claim
18 words
An active voltage probe according to claim 1 wherein said follower amplifier means comprises a source follower amplifier.
Claim 8
Dependent Claim
26 words
An active voltage probe according to claim 1 wherein said follower amplifier means comprises a combination of a source follower amplifier and an emitter follower amplifier.
References Cited (Backward Citations)
US3256484A
Cited
US3533004A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-09-05 | 1987-03-07 | 1987-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-05 | 1991-03-07 | 1991-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-05 | 1995-03-07 | 1995-09-06 | $7700.00 | Window Closed / Lapsed |