US5608329A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit test device
Assignee: Yokogawa Electric Corp
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Filing: 1995-02-24
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Granted: 1997-03-04
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Expires: 2015-02-24
Abstract
Abstract A circuit test device for carrying out a DC Test and a Function Test on a test object without using a relay, wherein a first differential circuit receives a signal from a test object; a current source supplies a current to the test object; a second differential circuit receives an output from the first differential circuit and supplies a current to the test object; a current measuring circuit measures the current flowing through the second differential circuit; and a control circuit controls the current source and the current in the second differential circuit while applying a voltage to the first differential circuit and provides a set voltage to the first differential circuit for the test object when carrying out the DC Test, and provides a set current in the second differential circuit when carrying out the Function Test.
Inventors
- 👤 Makoto Imamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 09:54
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/28; G01R31/30; G01R31/3004; G01R31/317; G01R31/3181; G01R31/319; G01R31/31917; G01R31/31924
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
174 words
A circuit test device comprising: a first differential circuit comprising two input terminals, said first differential circuit receiving a signal from a test object; a current source for supplying current to said test object; a second differential circuit comprising two output terminals, said second differential circuit receiving an output signal from said first differential circuit and supplying a current from one of said two output terminals thereof to said test object; a current measuring circuit for measuring a current flowing through said second differential circuit using the other of said two output terminals of said second differential circuit; and a control circuit for controlling said current source, said first differential circuit, and said second differential circuit, and for providing at an input terminal of said first differential circuit a set voltage for said test object when carrying out a DC test on said test object, and for setting a current in said current source and said current in said second differential circuit to 0 when carrying out a Function Test on said test object.
Claim 2
Dependent Claim
174 words
A circuit test device comprising: a first differential circuit comprising two input terminals, said first differential circuit receiving a signal from a test object; a current source for supplying current to said test object; a second differential circuit comprising two output terminals, said second differential circuit receiving an output signal from said first differential circuit and supplying a current from one of said two output terminals thereof to said test object; a current measuring circuit for measuring a current flowing through said second differential circuit using the other of said two output terminals of said second differential circuit; and a control circuit for controlling said current source, said first differential circuit, and said second differential circuit, and for providing at an input terminal of said first differential circuit a set voltage for said test object when carrying out a DC test on said test object, and for setting a current in said current source and said current in said second differential circuit to 0 when carrying out a Function Test on said test object.
Claim 3
Dependent Claim
17 words
The device of claim 1, wherein said first differential circuit comprises an input circuit of a comparator.
Claim 4
Dependent Claim
17 words
The device of claim 1, wherein voltage applied to said test object is measured through a buffer.
Claim 5
Dependent Claim
18 words
The device of claim 3, wherein said buffer comprises an input circuit of a comparator, and an amplifier.
Claim 6
Dependent Claim
36 words
The device of claim 1, wherein a driver is provided which adjusts a leak current on the basis of a voltage at a measuring terminal of said test object when said DC Test is carried out.
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) | 2000-03-03 | 2000-09-02 | 2001-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-03-03 | 2004-09-02 | 2005-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-03-03 | 2008-09-02 | 2009-03-04 | $7700.00 | Window Closed / Lapsed |