US3633016A
Expired / Lapsed
US
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Apparatus and method for testing electrical systems having a plurality of terminals
Assignee: Digital General Corp
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Filing: 1970-03-04
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Granted: 1972-01-04
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Expires: 1990-03-04
Abstract
Abstract Apparatus and method are provided for diagnostically testing electrical systems, such as printed circuit boards and integrated circuits. In testing electrical systems having a plurality of input terminals a test signal is applied to each input terminal and a comparison is made to verify whether or not any signal actually present on each input terminal corresponds with the applied test signal. In testing electrical systems having an output terminal which would normally provide a pulse signal in response to a test signal applied to an input terminal thereof, a test signal is applied to the input terminal and a signal comparison is made to verify whether any response occurring at the output terminal corresponds with a signal representative of the anticipated pulse signal response. Other features are disclosed including circuitry for selectively rendering various terminals of an electrical system as either input or output terminals, depending upon the types of tests to be made on the electrical system.
Inventors
- 👤 Jerome F Walker
- 👤 Stuart F Daniels
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 16:46
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/28; G01R31/2801; G01R31/2806
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
106 words
Apparatus for testing an electrical system having a plurality of input terminals and comprising a test circuit for each said input terminal, each said test circuit including: a test output circuit adapted to be electrically coupled to a said input terminal; means for applying a test signal to said test output circuit and, hence, to said input terminal; and input verification means coupled to said test output circuit and, hence, to said input terminal for receiving both said test signal and any signal actually present at said input terminal for electrically verifying whether said test signal corresponds with any signal actually present at said input terminal.
Claim 2
Dependent Claim
106 words
Apparatus for testing an electrical system having a plurality of input terminals and comprising a test circuit for each said input terminal, each said test circuit including: a test output circuit adapted to be electrically coupled to a said input terminal; means for applying a test signal to said test output circuit and, hence, to said input terminal; and input verification means coupled to said test output circuit and, hence, to said input terminal for receiving both said test signal and any signal actually present at said input terminal for electrically verifying whether said test signal corresponds with any signal actually present at said input terminal.
Claim 3
Dependent Claim
62 words
Apparatus as set forth in claim 1, wherein said test signal applying means includes binary signal means for selectively applying a binary ''''1'''' or binary ''''0'''' test signal to said input terminal and said input verification means serves to verify whether the binary level of said test signal corresponds with the binary level of any signal actually present at said input terminal.
Claim 4
Dependent Claim
49 words
Apparatus as set forth in claim 2, wherein said input verification means includes binary signal comparator means for providing an error output signal when the binary levels of said test signal provided by said binary signal means and any signal actually present at said input terminal do not correspond.
Claim 5
Dependent Claim
74 words
Apparatus as set forth in claim 3, including signal isolation means interposed between the output of said binary signal means and said test output circuit, said signal comparator means having one input for receiving said test signal from a circuit point between the output of said binary signal means and said signal isolation means and a second input coupled to said test output circuit for receiving any signal actually present at said input terminal.
Claim 6
Dependent Claim
162 words
Apparatus for testing an electrical system having a plurality of terminals and comprising for each said terminal: binary signal means for providing a test binary signal of a selected binary level; actuatable switching means adapted to be interposed between the output circuit of said binary signal means and a said terminal, said switching means having a first condition wherein a circuit is completed between the output circuit of said binary signal means and said terminal so that said terminal serves as an input terminal for receiving said test binary signal and a second condition wherein an open circuit is obtained between the output circuit of said binary signal means and said terminal so that said terminal serves as an output terminal; and signal verification means for receiving a said test binary signal and any signal actually present at said terminal for verifying whether the binary level of any signal actually present at said terminal corresponds with that of said test binary signal.
Claim 7
Dependent Claim
162 words
Apparatus for testing an electrical system having a plurality of terminals and comprising for each said terminal: binary signal means for providing a test binary signal of a selected binary level; actuatable switching means adapted to be interposed between the output circuit of said binary signal means and a said terminal, said switching means having a first condition wherein a circuit is completed between the output circuit of said binary signal means and said terminal so that said terminal serves as an input terminal for receiving said test binary signal and a second condition wherein an open circuit is obtained between the output circuit of said binary signal means and said terminal so that said terminal serves as an output terminal; and signal verification means for receiving a said test binary signal and any signal actually present at said terminal for verifying whether the binary level of any signal actually present at said terminal corresponds with that of said test binary signal.
Claim 8
Dependent Claim
45 words
Apparatus as set forth in claim 5, wherein said signal verification means includes binary signal comparator means for providing an output error signal when the binary level of any signal actually present at said terminal does not correspond with that of said test binary signal.
Claim 9
Dependent Claim
114 words
Apparatus as set forth in claim 6, including isolation means interposed between the output of said binary signal means and said terminal for, when said terminal serves as an input terminal for receiving said test binary signal, preventing the binary level of said test signal appearing at the output circuit of said binary signal means from being degraded as a result of a circuit malfunction within said electrical system being tested, said binary signal comparator means having one input for receiving said test binary signal from a circuit point between the output of said binary signal means and said isolation means and a seconD input for receiving any signal actually present at said terminal.
Claim 10
Dependent Claim
144 words
Apparatus as set forth in claim 5, wherein said electrical system being tested has a first terminal for providing a pulse signal in response to an input signal applied to a second terminal; control means for actuating said switching means for said first terminal to said first condition so that said first terminal serves as an output terminal and for actuating said switching means for said second terminal to said second condition so that said second terminal serves as an input terminal, whereby said input terminal receives said test binary signal from the binary signal means for said input terminal as an input signal and said signal verification means for said first terminal serves to verify whether the binary level of any signal actually present at said output terminal corresponds with said test binary signal from the binary signal means for said output terminal.
Claim 11
Dependent Claim
78 words
Apparatus as set forth in claim 8, including bistable means having an input circuit for receiving any actual signal present at said output terminal and an output circuit for providing a response binary signal when said actual signal is a pulse signal of a given polarity; and said signal verification means includes binary comparator means for providing an output error signal when the binary levels of said response binary signal and said representative binary signal do not correspond.
Claim 12
Dependent Claim
63 words
Apparatus as set forth in claim 9, including pulse signal inverting means interposed between said output terminal and said bistable means for inverting the polarity of any said actual pulse signal at said output terminal so that if said actual pulse signal is of the wrong polarity it will be presented to said binary signal comparator means as being of said given polarity.
Claim 13
Independent Claim
111 words
A method for testing electrical systems having a plurality of input terminals and comprising the steps of: utilizing binary signal generating means for selectively providing for each input terminal a test binary ''''1'''' or test binary ''''0'''' signal for application to said input terminal; for each said input terminal, utilizing a selected test circuit for applying a said selected binary signal to said input terminal; and for each said input terminal, utilizing said selected test circuit having signal verification means for providing an error indication when said test binary signal for said input terminal is of a different binary level from that of any signal actually present at said input terminal.
Claim 14
Independent Claim
111 words
A method for testing electrical systems having a plurality of input terminals and comprising the steps of: utilizing binary signal generating means for selectively providing for each input terminal a test binary ''''1'''' or test binary ''''0'''' signal for application to said input terminal; for each said input terminal, utilizing a selected test circuit for applying a said selected binary signal to said input terminal; and for each said input terminal, utilizing said selected test circuit having signal verification means for providing an error indication when said test binary signal for said input terminal is of a different binary level from that of any signal actually present at said input terminal.
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) | 1975-01-03 | 1975-07-05 | 1976-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-03 | 1979-07-05 | 1980-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-03 | 1983-07-05 | 1984-01-04 | $7700.00 | Window Closed / Lapsed |