Abstract: In a process for automatically detecting the response of an electromagnetic valve, in particular an electrovalve, an increasing testing voltage is applied to the valve and the instantaneous testing voltage at which the electromagnetic valve responds is fixed and indicated in that the monetary decrease of the current flowing through the valve is detected and utilized for fixing and indicating the instantaneous value of the testing voltage. A device for automatically detecting the response voltage of the electromagnetic valve includes an indicating device (8) which is controllable in such a way that it indicates and fixes the value of the testing voltage applied to the electromagnetic valve as soon as the valve responds to the testing voltage.

Abstract: By providing two comparators, each of which have a reference voltage level source connected to one input, and separate voltage level producing/enhancing circuits connected to the contacts of a relay, so that each alternate switch configuration produces a different voltage level at the two comparators, a unique relay switch detection circuit is attained. Preferably, three separate voltage level producing/enhancing circuits are employed, with one circuit connected between the relay output and the two comparators, while the other two circuits are connected to the primary or the secondary relay contacts. Futhermore, the voltage level resulting from each particular switch configuration is pre-set relative to the reference voltage level source imputs to assure that the two comparators produce different combined outputs for each alternate switched condition.

Abstract: By providing control logic for initiating a predetermined test sequence depending upon the known state of a relay, a unique testing circuit is attained whereby the relay drivers connected to the opposed sides of the relay coil are fully evaluated without causing the relay to be activated. In the preferred embodiment, the relay comprises a latching-type relay and the relay drivers comprise separate high-power CMOS devices. In this configuration, the control logic separately activates each transistor of each of the high-power CMOS devices without causing the relay to be switched between its two alternate configurations. Furthermore, the control logic originally sets the latching-type relay into one of its two configurations and then shuts off the power until activated for initiating the test sequence. In addition, the control logic is employed to check each transistor during the test sequence and assure its operation.

Abstract: A method and system (1) for adjusting the curvature of an electrical relay armature (4), and the energizing voltage level of the electrical relay (2) in which it is contained, is disclosed. The adjustment system (1) uses a rotatable carrier (16) from which an extendable cam (22) with a shaped bearing surface (23) directly communicates with, and provides necessary adjustment to, a curved armature section (8) of a misconfigured relay armature (4). The necessary adjustment is determined and controlled by a controller in combination with an energizing level determining device.

Abstract: A visual indication system for easily providing information about the status of the output terminals of a solid state relay. A two-electrode neon glow lamp is connected across the output terminals of the relay in series with a current limiting resistor. The shunting impedance of the relay output terminals prevents voltage from inducing a glow in the neon lamp in certain modes of terminal configuration. When the terminals are ON, neither electrode glows. When the terminals are OFF, both electrodes glow. If the AC relay fails in a half-wave mode, only one of the electrodes will glow.

Abstract: The operation of an electromagnetic valve is monitored by connecting the coil of the valve to a d.c. source for a period of time sufficient to permit the current in the coil to reach its maximum steady state value then disconnecting the coil to permit the current to fall and re-connecting the coil to the source again and measuring the current which is established in the coil.

Abstract: A method for error-protected switching operation of switching devices of a high-voltage switching station. The current operational state of the station is determined from the signals provided by position indicating contacts (K.sub.I, K.sub.II, K.sub.III) of the switching devices. Using the obtained operational state, switching operation request commands (for example KA) are checked for release or blocking status by means of error-protected switching interlocking rules. In the case of changes in the topological configuration of the high-voltage switching station and/or in the case of changes of the error-protected switching interlocking rules, it is possible to adapt the basic method to these changes in a simple manner and without losing operational reliabilty. This is achieved by decoupling the topological configuration of the high-voltage switching station from the error-protected switching interlocking rules.

Abstract: An electromagnetic valve used in controlling the amount of supplementary air supplied to an internal combustion engine to control the idling operation thereof is controlled by a current controller. The actual value of current flowing through the electromagnetic valve is compared with a predetermined value when a control signal, which is applied to the controller to regulate the opening of the electromagnetic valve, and the actual value of the current do not exhibit a predetermined correlation. It is determined whether an abnormality in the current controller is a disconnection or a short circuit based on whether the actual value of the current is greater than the predetermined value.

Abstract: An apparatus for testing current sensors employing an electromagnetic coil and one or more Hall Effect switches including a microprocessor controlling a constant current source and visual and audio indicating circuits. A parameter input circuit is provided to permit an operator to select device types and to select test only, or adjustment and test sequences to be executed. The constant current source is adapted to apply a threshold, must-not-operate, and a must-operate current values to the electromagnetic coil. The visual and audio indicating circuits are adapted to provide messages, pass/fail indications, and audio signals signaling test success or failure results to an operator.

Abstract: A method of adjusting and testing for proper operation a current sensor by applying a threshold current value to the current sensor and adjusting the current sensor to a point just past the threshold of operation. Proper operation of the current sensor is tested by applying a non-operate current value followed by an operate current value to the sensor and checking for respective non-operate and operate output signals from the sensor. Messages, pass/fail indication, and audio signals are provided to signal test results to an operator.

Abstract: A digital protective relay monitoring system for testing the analog input section of the relay by application of a monitoring signal, with a frequency different from the power frequency, superimposed on the line voltage and current sensor signals. After the signals have been sampled in the form of digital data, the monitoring signal component is extracted through the digital filtering process and compared with the reference value, and a fault in the analog input section of the relay is detected on the basis of the result of comparison.

Abstract: A test device for testing an actuator circuit without operating an actuator in the circuit to determine whether the circuit is operating normally comprises a relay input and a relay output which are electromagnetically coupled or optically coupled. The relay input is connected in series with a test circuit power supply for initiating the test and operating the relay output which is connected with an actuator power supply and an actuator. A voltage limiting device is connected in series with the relay output for limiting the magnitude of the voltage supplied to the actuator at testing time so that the actuator is not operated. The test circuit power supply further includes a pulse generating circuit for generating a signal pulse having a pulse width less than a predetermined pulse width normally required to operate the actuator.

Abstract: A programmable controller system is taught which uses an oscillator to provide a relatively low frequency low duty cycle series of digital ones and zeros to the gate logic of a load control device regardless of whether the device is in the ON or OFF state. These signals are electrically passed through the system which controls the load for such a short time that the load cannot change state because of electrical momentum and/or inertia thereof. The series of digital ones and zeros nevertheless do pass through the system and sensing means serve to test the correct operation of the output devices. As long as the oscillator generated signals continue to pass through the gate, the capacitor controlled sensing devices will be held in a state such as to provide no indication of failure.

Abstract: An arrangement for detecting faults in automatic test systems of the type wherein test points in a unit under test are connected to test instruments by the programmed closure of electromechanical relay contacts. Respective contacts of the relays are connected to each other and, during periods intermediate of the closure of the relays, a detector circuit is coupled to the interconnected relay contacts. The detector circuit compares a voltage or resistance present on the interconnected relay contacts to a threshold. In one embodiment, if a difference between a signal on the interconnected relay contacts and the threshold persists for a predetermined period, an interrupt signal is generated which prevents further closures of the relays. In this manner, catastrophic failures of the unit under test and the test instruments are prevented.

Abstract: Equipment is provided to test an electrical device, e.g. solenoid, or heater that effects an operation, e.g. movement of a valve, heating etc. To perform a test, the equipment actuates the device to cause the operation to commence. When the operation has proceeded to a predetermined extent, or after a predetermined time, whichever occurs first, a signal is produced which causes de-actuation of the device thus stopping the operation. A signal is also produced to indicate whether it was the elapse of the specified time or the operation proceeding to the specified extent that caused de-actuation. The equipment is particularly suited for testing a device forming part of a trip system.

Abstract: A testable physically isolated control circuit includes a first unit 10, a second unit 40, and an optical coupler 30 to couple units 10 and 40 together. The functional portion 10a of the first unit includes an input terminal 11 and an oscillator 12 for controlling a first transmitter 17. Signals from the first transmitter are received by a receiver 44 in unit 40 to control the relay 48. Each unit 10 and 40 also includes a testing portion 10b and 40b for monitoring the condition of the functional portions. The testing portion 40b detects the state of the receiver 44 and the relay 48 and transmits this information via transmitter 65 to a receiver 22 in first unit 10. This receiver 22 controls input terminals 29 and 15 to provide control information concerning the proper functioning of the circuit.

Abstract: The invention relates to a testing and evaluating circuit for a proximity itch suitable for testing and provided as an element of a machine control means; associated with the proximity switch is a control circuit, by which the proximity switch is alternately switchable between its two operating conditions to generate a timed output signal with a given frequency, an evaluating circuit being provided, by which a clear signal indicating fault-free operation is producable for the duration of a timed output signal from the proximity switch and by which a blocking signal for the machine control means, indicating a fault, is producable in the absence of changes in the potential of the output signal from the proximity switch. The evaluating circuit preferably comprises a relay circuit, to which the output signal from the proximity switch or a signal derived from this is fed via a transformer.

Abstract: In a relay tester, analog signals to be supplied to a relay under test are processed with digital circuits so that the concerned frequency, phase, voltage and current are set and adjusted with high frequency.

Abstract: Relays and similar devices are tested by applying electric power to the coil to actuate the armature, measuring armature travel and comparing the measured travel to a datum to produce a percentage relationship. Datum values for the armature travel required to actuate each contact are connected by this produced percentage relationship to produce new datum values for each contact. The armature travel at actuation of each contact is measured and compared to the new or connected datum values. Output signals are desired for the actuation of each contact indicative of the relationship between actual actuation travel and the new datum values.

Abstract: An apparatus for testing enclosed electromagnetic relays includes a probe displaceable into the relay enclosure to engage the movable contact thereof. The probe is associated with a force transducer and a displacement transducer which provide inputs to a circuit including microprocessor unit which operates to detect the probe force required to break contact between the movable contact and the normally closed contact and to detect the position of the probe when such break occurs and when the normally open contact is made and to calculate the contact travel from the position signals it receives. Contact over travel is also measured by applying current to the relay winding and measuring probe displacement required to re-engage the contact.

Abstract: A method of automatically plotting the loci curves of multi-stage distance relays. The comparison impedances, required for the measurement, are automatically provided for given impedance angle by adjustable currents and voltages. During the determination of the loci curves there is started with a defined, predetermined impedance value which is either greater or smaller than that which is sought to be found. By taking the half of this impedance value or by doubling with subsequent halving, when starting with smaller impedance values, it is possible to incrementally approach the sought of impedance value as a function of whether or not, for the corresponding timing stage of the distance relay, its measuring element responds or does not respond.

Abstract: A test apparatus for checking test objects, such as protective relays, especially voltage, current and/or frequency relays for the protection of a generator of a power supply network, comprising a first circuit for generating and converting test signals or magnitudes to be delivered to the test objects and a second circuit for pre-programming the test signals or magnitudes to be delivered to the test objects. The first circuit comprises a first test signal generating circuit for supplying the voltage relay and the current relay with voltage and current test signals, respectively, and contains a first secondary winding of a test transformer. A static potentiometer is connected in parallel with this first secondary winding. The potentiometer supplies test signals in finely stepped or graduated values to the test objects. The first circuit further comprises a second test signal generating circuit for supplying the frequency relay with frequency test magnitudes.