| Patents for G01R 19 - Arrangements for measuring currents or voltages or for indicating presence or sign thereof (29,850) |
|---|
| 04/24/1990 | US4920311 User selection of meter ballistics |
| 04/24/1990 | US4920310 Voltage detector |
| 04/24/1990 | CA1268220A1 Voltage sensitive switch |
| 04/19/1990 | WO1990004186A1 Repetitive wave sampler |
| 04/18/1990 | EP0363830A1 Electrical installation with a galvanic signal-carrying conductor, and an interference indicator therefor |
| 04/18/1990 | CN1041505A Computerized tester of x-ray apparatus |
| 04/17/1990 | US4918392 Polarity tester for devices incorporating socket means for power transmission to active elements |
| 04/11/1990 | CN2055940U Colour changing logic pen |
| 04/11/1990 | CN2055939U Electronic test pencil for car |
| 04/10/1990 | US4916570 Voltage comparator circuit for monitoring a process output voltage within a preset range |
| 04/10/1990 | US4916385 Inverter circuit |
| 04/05/1990 | WO1990003582A1 Voltage, current and frequency measuring of non-standard waveforms |
| 04/05/1990 | WO1990003581A1 Current sensor circuit |
| 04/04/1990 | EP0361868A2 Liquid crystal display device |
| 04/03/1990 | US4914680 Signal distinction circuit |
| 03/28/1990 | EP0360574A1 Current sensor having an element made of amorphous magnetic metal |
| 03/28/1990 | EP0360348A2 Process and device for measuring small electrical signals |
| 03/28/1990 | CN2055258U Weak current clamp-on ammeter |
| 03/28/1990 | CN1040868A Voltage tester with segmental light indication and manufacturing method thereof |
| 03/27/1990 | US4912774 Instantaneous voltage drop detector |
| 03/27/1990 | US4912729 Phase-locked-loop circuit and bit detection arrangement comprising such a phase-locked-loop circuit |
| 03/27/1990 | US4912052 Method of testing semiconductor elements |
| 03/27/1990 | EP0226631A4 Method and apparatus for editing particle produced electrical pulses. |
| 03/27/1990 | CA1267193A1 Transit system third rail warning signal |
| 03/22/1990 | DE3831678A1 Circuit arrangement for measuring peak values |
| 03/21/1990 | EP0359666A1 Fibre-optical measuring system, gyrometer, navigation and stabilization system |
| 03/21/1990 | EP0359633A1 Logarithmic envelope detector for an analog signal |
| 03/21/1990 | EP0359326A2 Full-wave rectifier circuit |
| 03/21/1990 | EP0359171A2 Circuit for sensing the transistor current waveform |
| 03/21/1990 | EP0358757A1 Measurement of the variation in time of a periodic signal |
| 03/21/1990 | CN2054907U 试电笔 Test pencil |
| 03/20/1990 | US4910458 Electro-optic sampling system with dedicated electro-optic crystal and removable sample carrier |
| 03/20/1990 | US4910455 Non-intrusive current measuring circuit |
| 03/20/1990 | US4910454 System for electrical signal sampling with ultrashort optical pulses |
| 03/14/1990 | EP0358189A2 Level determining circuit generating output signal at first or second output terminal according to level of input signal |
| 03/14/1990 | EP0357707A1 Current fault protection system |
| 03/14/1990 | CN1040457A 功能开关 Function Switch |
| 03/14/1990 | CN1007181B Micro-electric current meter |
| 03/13/1990 | US4908753 High-tension power supply for an image recorder |
| 03/13/1990 | US4908575 Circuit for measuring diffusion-limited current |
| 03/13/1990 | US4908569 Transformerless line powdered digital AC voltmeter |
| 03/13/1990 | US4908568 Mechanical probe for optical measurement of electrical potentials |
| 03/13/1990 | CA1266703A1 Fault indicator having improved trip inhibit circuit |
| 03/07/1990 | EP0357591A2 Charge amplifier circuit |
| 03/07/1990 | EP0357438A2 Ultra-high-speed digital test system using electro-optic signal sampling |
| 03/07/1990 | EP0357285A2 Power supply for outdoor lighting systems |
| 03/07/1990 | EP0357111A2 Detection circuit for several voltage ranges |
| 03/07/1990 | EP0356696A1 Device for measuring the currents of phases in a three-phase system |
| 03/07/1990 | EP0356555A1 Method and circuit arrangement for determining the presence or not of at least one frequency of a known value in an input signal composed of multiple frequencies |
| 03/07/1990 | CN2054167U Active high-voltage electroscope |
| 03/06/1990 | US4907121 Comparator with extended common-mode input voltage range |
| 03/06/1990 | US4906901 Power supply for outdoor lighting systems using high frequency |
| 03/06/1990 | US4906055 Voltage level judging device |
| 02/28/1990 | EP0356273A1 Main and secondary optical sensor device |
| 02/28/1990 | EP0356248A1 A current sensor |
| 02/28/1990 | EP0355506A1 Arrangement for measuring local bioelectric currents in biological tissue |
| 02/28/1990 | EP0355461A2 Monitoring device for electric storage battery and configuration therefor |
| 02/28/1990 | EP0355197A1 Voltage probe for the stepwise optical display of a voltage, and process for producing it |
| 02/27/1990 | US4904945 Apparatus and process for detecting direct current magnetic flux deflections in an electrical transformer employing Fourier analysis |
| 02/27/1990 | US4904925 Apparatus for recovering an alternating variable of a controlled semiconductor |
| 02/27/1990 | US4904888 Sense amplifier circuit |
| 02/22/1990 | DE3827758A1 Device for monitoring a predetermined current strength in at least one electrical conductor |
| 02/21/1990 | CN2053346U Four-purpose electricity test pencil |
| 02/21/1990 | CN2053345U Multipurpose electricity test pencil |
| 02/21/1990 | CN2053344U Digital voltage test pencil |
| 02/21/1990 | CN1006950B Method and apparatus for editing particle produced electrical pulses |
| 02/20/1990 | US4902913 Analog comparator |
| 02/20/1990 | US4902910 Semiconductor device |
| 02/14/1990 | EP0354841A1 Appliance for monitoring the electric power disequilibrium in electric network lines or in an internal triphase installation |
| 02/14/1990 | CN2052905U Trouble alarm for on-load automatic voltage-regulating transformer |
| 02/14/1990 | CN1039665A Bidirectional dc power controller with fault protection |
| 02/13/1990 | US4901006 Method and apparatus for AC signal comparison, calibration and measurement |
| 02/13/1990 | US4901005 For a three phase power system |
| 02/13/1990 | US4900952 Voltage comparison apparatus |
| 02/13/1990 | CA1265844A1 Line mounted apparatus for measuring line potential |
| 02/08/1990 | WO1990001170A1 Device with main and secondary optical sensors |
| 02/08/1990 | DE3826551A1 Method for measuring power factors and/or reactive current |
| 02/07/1990 | EP0215810B1 Circuit for obtaining an average value |
| 02/06/1990 | US4899068 Comparison circuit with error compensated mos switches |
| 02/06/1990 | CA1265584A1 Directional current finder |
| 02/06/1990 | CA1265583A1 Apparatus for measuring low currents with high dynamics |
| 02/06/1990 | CA1265582A1 Current sensing alarm arrangement for monitoring the presence of high voltage |
| 01/31/1990 | EP0353039A1 Compensated current sensing circuit |
| 01/31/1990 | EP0352734A1 Circuitry for monitoring a voltage source relative to two reference voltages |
| 01/31/1990 | CN2052157U Leakage-indicating plug |
| 01/31/1990 | CN2052125U Multifunctional test pencil for vehicle |
| 01/30/1990 | CA1265197A1 Potential indicating device |
| 01/25/1990 | WO1990000849A1 A real-time signal processing circuit |
| 01/25/1990 | WO1990000741A1 Improvements relating to electric current measuring devices |
| 01/25/1990 | WO1990000740A1 Adjustment circuit and method for solid-state electricity meter |
| 01/25/1990 | DE3825160A1 Measuring instrument for radio-frequency signals |
| 01/24/1990 | EP0352155A1 Threshold measuring process for a noisy signal, and appliance for automatic measuring according to this process |
| 01/24/1990 | EP0351900A2 Logic analyser with configurable multi-levels |
| 01/24/1990 | EP0351833A2 Plant fault diagnosis system |
| 01/24/1990 | EP0351601A1 Detection circuit for small amplitude high-frequency signals |
| 01/23/1990 | US4896118 Variable gain current-to-voltage amplifier with gain independent test mode operation |
| 01/23/1990 | US4896104 Digital peak and valley detector |
| 01/23/1990 | CA1264810A1 Cable mounted capacitively-coupled circuit condition indicating device |
| 01/23/1990 | CA1264809A1 Voltage loss detector |
| 01/17/1990 | EP0350662A2 Process and appliance for determining pulse currents in lightning conductors or similar devices |