Matches 101 - 150 out of 152 < 1 2 3 4 >
Match Document Document Title
4642557 Method of and apparatus for detecting erosion  
A predetermined amount of erosion of a material conveying conduit or the like is detected by inserting a probe in the conduit wall, from the side opposite to that subjected to the wear, to a...
4550286 Onboard method of detecting electrical faults in a vehicular air suspension system  
A method of detecting electrical faults that may occur in a vehicular air suspension system utilizing height sensors and air springs mounted between sprung and unsprung components of the vehicle....
4375072 Self-calibrating overcurrent detector  
Circuit for detecting a fault current in an installation where the load (RL) varies. Total current (IS) is converted into a voltage (VS). During an initialization cycle, means such as counter (9),...
4363105 Microcomputer-controlled circuit tester  
To test the integrity of a plurality of operating circuits each including a load energizable by an associated driver under the control of a microcomputer, a capacitor charged with unipolar...
4298969 Method and apparatus for testing the impedances of geophone channels  
This application relates to seismic data gathering devices and to testing the impedances of the geophone channels of such devices. The invention includes impressing a test current on each channel...
4276619 Impedance and common mode rejection testing of a multi-channel seismic data gathering apparatus  
This relates to testing the impedance and common mode rejection characteristics of multi-channel seismic data gathering apparatuses. The apparatus embodying the invention includes a signal...
4276605 Method and apparatus for supervising a digital protective relaying system  
In a method and apparatus for supervising a digital protective relaying system, a first type of electrical quantities in an electric power system, each having a certain magnitude, are detected,...
4187504 Fault monitoring and indicator system  
A continuity monitor and indicator circuit for monitoring the continuity of a segment of a pair of control conductors along which a control current flows includes capacitors at each end of the...
4164701 Portable device for testing electrical wiring circuits and power tools and equipment  
A portable testing device is disclosed for testing the electrical circuits of power tools and cables having a general three-conductor wiring circuit including a first test station for checking the...
4155036 Apparatus for testing cooking range electrical circuitry  
A test circuit for testing electrical characteristics of heating elements and switches coupled to individual elements. The switches are manually operated and conventionally may be mounted on a...
4118690 Electrical hazard indicator  
An indicator device having a single indicator which is momentarily activated during connection of the device, i.e. to a power source, to indicate availability of electrical power and operability of...
4117397 Non-destructive insulation test apparatus  
A non-destructive insulation test method and apparatus therefor, wherein in non-destructively testing the behavior of insulation by applying a high d.c. voltage to a test piece, stepped test...
4117463 Circuit fault detection apparatus for railroad track circuit redundant connections  
Continuity detector apparatus is coupled into duplicate conductors connected in parallel between each rail of a track section and an energy source or occupancy receiver of an associated track...
4110807 Continuity monitoring system  
Disclosed is a system for monitoring the resistance in the pilot and ground conductors of a power cable and for interrupting power if the resistance exceeds a predetermined limit established for...
4037220 Circuit arrangement for monitoring interruptions in two closed-circuit loops  
A circuit arrangement for monitoring interruptions in each of two closed-circuit loops, which loops are laid in at least one cable. One end of each loop is connected, with the optional...
3955183 Alarm condition sensing and indicating circuit with test capability  
An alarm circuit includes an alarm condition indicating section having an alarm indicator, such as a lamp, and a power supply therefor, the lamp becoming illuminated in response to sensing of an...
3946573 Electrical diagnostic system for refrigeration apparatus  
A diagnostic system for use with refrigeration apparatus and the like for selectively indicating the operability condition of different electrical components thereof. The indicating apparatus is...
3878458 Electrical safety test apparatus for detecting leakage current tripping current and proper grounding  
A device for testing the safety of operating electrically powered tools, particular at building sites. A compact housing contains an ammeter or other current indicating device, electrical circuitry...
3875510 Synchro testing calibrating device  
A device for calibrating and trouble shooting servo systems. Single and tty-six speed test synchro receivers are connected to the servo systems by means of reversing switches and no external source...
3836854 ALARM CIRCUIT FOR MONITORING THE AMPLITUDE OF A-C VOLTAGES  
A circuit for rapidly and accurately indicating whether an a-c voltage has a magnitude greater than a predetermined minimum value. A two-state voltage comparing circuit establishes a first output...
3796966 NOISE-REDUCTION AMPLIFIER  
A noise-reduction amplifier in an optical-sound recording system for motion pictures wherein the noise-reduction amplifier furnishes a variable bias signal to a galvanometer, the magnitude of the...
3795858 INVERTER RATIO FAILURE DETECTOR  
A failure detector which detects the failure of a DC to AC inverter is disclosed. The inverter under failureless conditions is characterized by a known linear relationship of its input and output...
3746981 ELECTRICAL FAULT MONITORING WITH MEMORY  
Means for monitoring electronic equipment and detecting faults including memory means whereby transient or intermittent faults may be identified and corrected after an interval of time.
3737769 AUTOMATIC INSULATION CHARACTERISTIC ANALYZING DEVICE  
A rectifier and integrator circuit is provided for rectifying an alternating current voltage corresponding to that applied across a specimen to be tested and obtaining the mean value V of the...
3727105 FAIL-SAFE POWER CUT-OUT DEVICE  
A circuit is disclosed in which one or more power line fuses are automatically blown in the event of an open circuit or other interruption in the power circuit so as to prevent electric shock to...
3725636 AC-DC SHORT CIRCUIT WELDING INDICATOR  
A circuit for indicating the occurrence of a short circuit between an electrode and a workpiece including an oscillator; a transformer having tertiary windings, the primary winding being connected...
3714455 INSULATION TESTER  
An insulation tester comprising a down-the-hole switching element and an out-of-the-hole switching element using a parallel-opposing combination of a rectifier and a thyristor, a control unit, a...
3704411 PORTABLE DEVICE FOR TESTING ELECTRICAL APPLIANCES  
A device operable as a torch or a testing device to test the circuitry of an electrical appliance for safety. The appliance is plugged into the device whereby the device can indicate the continuity...
3693077 ELECTRIC DRILL  
An electrical drill for drilling oil and gas wells is disclosed. The electrical drill comprises a housing which accommodates a three-winding-phase electric motor with a cable lead-in powered...
3657602 METHOD AND MEANS FOR DETECTING INCIPIENT CAPACITOR FAILURE  
Incipient failure of a capacitor operating as a part of an induction furnace circuit is detected by monitoring the capacitor to determine the presence of high-frequency signals generated by the...
3617886 TRANSDUCER OPEN-CIRCUIT FAILURE DETECTOR  
A high-impedance, open-circuit detector having a thermocouple generating a voltage proportional to the temperature level established by a controllable heater. The detector circuit voltage is...
3590373 STRAY VOLTAGE AND CONTINUITY TEST DEVICE  
A test device adapted for measuring AC voltage, DC voltage, and resistance n missile circuits without changing the interconnection between the missile circuits and the test device. The test device...
3579103 ANALOG-TO-DIGITAL CONVERTER TESTER  
Apparatus for automatically testing an ADC for open and short circuits. A tester is connected to the contacts on the ADC shaft. The ADC motor turns the ADC shaft to a specific setting and in...
3543111 VENDING MACHINE OPERATION SIMULATOR AND TESTER  
3535638 ELECTRICAL UNIT FOR USE IN TESTING OR REPAIRING TELEVISION RECEIVER SETS INCLUDING MEANS FOR DETACHABLE FASTENING TO THE SET  
3480863 RECEIVER SYSTEM HAVING VISUAL INDICATOR FOR CHANGES IN ELECTRICAL STATE  
3467867 APPARATUS FOR DETERMINING THE OPERABILITY OF VEHICLE RADIO COMPONENTS  
3447079 MONITORING CIRCUIT FOR SEQUENTIALLY TESTING HOT SIZING PRESS RESISTANCE HEATERS CONNECTED IN PAIRS DURING ENERGIZATION OF THE MATE HEATER  
3417326 Test unit for checking electric circuitry of a pumping machine  
3368146 Electrical safety tester having a plurality of switches for setting up tests  
3339113 Electric control system with means for adjusting potential of accidental ground  
3305772 Timer sequence tester having plural lamp indicators and template means  
3158806 Apparatus for performing a ground line continuity test at reduced voltage  
3111613 Synchro rotation malfunction translator  
2994819 Electrical power tool tester  
2991397 Protective system for detecting breakdown resistance that would cause a short or ground of a power circuit  
2957109 Overcurrent protection devices  
2858507 Electric testing device  
2806993 Tool tester  
2805387 High voltage tester for television receivers  
Matches 101 - 150 out of 152 < 1 2 3 4 >