Voltage and continuity tester
US4825150A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 24, 1987 |
| Grant date | Apr 25, 1989 |
| Priority date | — |
| Expiry date | Dec 24, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/54
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A battery powered tester has an electrical testing circuit combining continuity, polarity, and voltage amplitude circuits. The testing circuit for measuring a test voltage or relative continuity has first and second inputs to which first and second test points can be respectively coupled by RED and BLACK prods. The continuity, polarity, and voltage amplitude circuits are coupled in parallel to the first and second inputs, the polarity circuit being symmetrically coupled to the inputs. The polarity circuit has first and second polarity lamps and a sensing circuit for lighting the first polarity lamp when the test voltage is positive and lighting the second polarity lamp when the test voltage is negative. The continuity circuit has a continuity lamp separate from the polarity lamps and a driving circuit for lighting the continuity lamp whenever a zero or low passive impedance is coupled to the first and second inputs. A transistorized switching circuit monitors the difference in voltage between the first and second inputs, and if the difference equals or exceeds a predetermined continuity limit voltage, the switching circuit disables the signal to the driving circuit. The voltage amp…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.