Abstract: A voltage detection circuit includes a first resistive arm receiving an internal voltage to produce a basic current, current amplification circuitry to produce a reference current proportional to the basic current, a second resistive arm to produce a reference voltage representing the reference current, a voltage source to produce a control voltage from the reference voltage and a logic circuit to produce a binary signal from the control voltage, the state of the binary signal representing the value of the internal voltage.

Abstract: A digital processing system including a first processor (11) and a second processor (21) connected in series between a first power supply node (101) and a second power supply node (103). The second processor is configured to operate at a variable processing rate, as controlled by the output of a processing rate controller (33) that is responsive to the voltage across the supply terminals of the second processor and a first reference voltage. An auxiliary shunt regulator (39) is connected across the supply terminals of the second processor and is controlled by a regulator controller (37) to prevent the voltage across the supply terminals of the second processor from exceeding a second reference voltage.

Abstract: An electrical strike sensing system for providing an alarm if the underground boring equipment encounters a potentially hazardous condition. The system senses current carried through the equipment, as well as the voltage between the equipment and a reference. The measured current is converted to a percentage of a reference current, and the voltage is converted to a percentage of a reference voltage. The current and voltage percentages are added, and if the sum exceeds 100%, the alarms are activated. The current and voltage percentages, as well as the date and time of the strike, are stored in a nonvolatile memory.

Abstract: The invention relates to a method for supervising the functioning of a plurality of valve units, a system for performing the method, a control unit and a control assembly for cooperation with the control unit. Each valve unit in the system comprises a semiconductor element (THY1-THYN) and a control unit for controlling the semiconductor element. The control unit comprises a trigger order input for receiving a trigger order (FP), an indication output for emitting a first indication signal (TP) and a trigger signal output (100) for emitting a trigger signal to the semiconductor element. The method comprises the steps: detecting a positive forward voltage (U.sub.T) across the semiconductor valve, generating a first indication signal (IP) when the forward voltage (U.sub.T) exceeds a first threshold value (U.sub.1), generating a trigger signal upon detected receival of the triggering order signal (FP), and the step: generating a second indication signal (SSTP) when the forward voltage (U.sub.

Abstract: A control system comprises a controller for controlling an actuator, for instance of an electrically power assisted vehicle steering system. An unstable circuit, such as first and second cascade connected integrators has an input connected to the controller and an output connected to a detector, which signals an error when the output signal of the unstable circuit is outside an acceptable range. During normal operation, the controller supplies a signal to the unstable circuit such that its output signal remains within the acceptable range. The error signal may be used to disable the actuator, for instance so as to remove power assistance from steering system.

Abstract: An apparatus for testing the operativeness of a squib in an active restraint system wherein the squib has a resistance value, when operative, within a predetermined range of resistance values. The squib is connected in series with a firing circuit to a first source of electrical energy. A monitoring circuit includes a second source of electrical energy and a bridge circuit. The bridge circuit includes a biasing resistor network and a reference resistor network, both networks being operatively connected to the second source of electrical energy. The biasing resistor network establishes a flow of test current through the squib, the test current being the only continuous non-actuating current through the squib. The biasing resistor network establishes a test voltage value at one terminal of the squib. The monitoring circuit further includes a comparator for comparing the test voltage value at the one terminal of the squib against the squib reference voltage value of the reference resistor network.

Abstract: An electronic circuit breaker is provided with a plurality of air coils, each of which is coupled to a main circuit and an overcurrent signal integrating circuit which receives the output of the air coil to output an overcurrent signal when the current through the main circuit exceeds a predetermined value. A current signal simulating an overcurrent in the main circuit is fed from an external testing device into a current signal receiving terminal (CST). A test voltage generating resistor (TVGR) is connected between the CST and ground. The current signal flows through the TVGR to develop a test voltage across the TVGR. Thus, the overcurrent signal integrating circuit simulates the overcurrent signal on the basis of the test voltage.

Abstract: A voltage regulator, a device driver, and a warning signal driver are provided on a single voltage regulator integrated circuit. The voltage regulator provides a regulated voltage for external logic such as a microcontroller. The device driver selectively turns on or turns off an external device such as a relay. The warning signal driver outputs a warning signal. The integrated circuit contains sensing circuits which sense if the output voltage is out of proper regulation. In the event of a malfunction, for example when the output voltage is outside a desired voltage range, the device driver shuts off the external device and the warning signal driver generates a warning signal. The integrated circuit may also receive signals from the external logic which cause the integrated circuit to shut off the device or to generate a warning signal.

Abstract: The present invention relates to a digital angle detection system, or more particularly, to provide a digital angle output that is stable and the least affected by a cable length or the like. A digital angle detection system of the present invention uses a phase signal [sin(.omega. t-90.degree.-.theta.)] produced by synthesizing a phase-shifted resolver signal cos.theta..multidot.sin(.omega. t-90.degree.), which is 90.degree. out of phase with one resolver signal cos.theta..multidot.sin.omega. t, with the other resolver signal sin.theta..multidot.sin.omega. t.

Abstract: A revenue accuracy meter and a method are provided for measuring the amount and quality of power received by a power customer across electrical power lines. The revenue accuracy meter preferably has a variation determiner for determining undesired variations in an electrical signal representative of power received by the power customer during a plurality of predetermined time periods. A power usage measurer is coupled in electrical communication with the variation determiner for measuring the power usage of a customer responsive to an electrical signal representative of a customer load. The meter further has a communications interface coupled in electrical communication with the variation determiner and the power usage measurer for communication signals representative of the power variations and the power usage.

Abstract: A device is adapted to be associated with a group of input or output channels, especially of a programmable automatic controller, to detect if the channels are subject to an open circuit and/or an overcurrent. To each channel are assigned two analog comparators connected to a processor logic circuit which connects one or the other comparator output to a control unit. Configurator logic activates or deactivates one or the other of the comparators and associated forcing devices and filters according to the operating mode selected.

Abstract: A monitoring apparatus for an alarm device for situations wherein the alarm device is provided at a location remote from the alarm device drive side, which can verify from the alarm device drive side if an audible alarm has sounded. The drive of the alarm device (1) is stopped by switching off a drive switch (12) on the alarm device drive side (A). After stopping the drive of the alarm device (1) an audible alarm generation sensed signal from the response device (2) on the alarm device side (B)is received at the alarm device drive side (A) though the feeder (a). Then, after the audible alarm generation sensed signal has stopped, and on receipt of a verification signal verifying that the alarm device drive side (B) has returned to the original condition, a verification output (F3) for the audible alarm generation is generated at the alarm device drive side (A).

Abstract: A fluid level sensing system, particularly for sensing the water level in a steam generating boiler, comprises a vessel connected to the boiler so as to contain water and steam at substantially the same level as in the boiler, a number of vertically spaced electrodes projecting into the vessel, and circuitry for measuring the electrical impedance sensed by each electrode. The circuitry, which can be multiplexed to each electrode in turn, includes a first comparator for producing an output when the sensed impedance lies between the normal maximum impedance of the water and the normal minimum impedance of the steam above the water, this output being demultiplexed to drive a vertical display to show the level of the steam/water interface. The circuitry additionally includes a second comparator for producing a further output when the sensed impedance lies below the normal minimum impedance of the water, which further output is indicative of a variety of different fault conditions and drives a fault indicator.

Abstract: A computer comprising a main body, a connector having pins for connecting an external display to the main body, a register for storing data representing a first status or a second status in accordance with the voltage of specified ones of the pins of said connector means, and a display controller for controlling the external display. The computer further comprises a data-reading section for repeatedly reading the data stored in the register and counting the number of times the data representing the first status is read from said register means, and detecting section for determining that the external display is connected to the connector when the number of times the data representing the first status is read from the register reaches a prescribed value.

Abstract: In an electric circuit supplying AC line current to a load (30, 31) from an AC source (26) of given frequency providing repetitive cycles, arc detection is provided by sensing cycle to cycle changes in the AC line current. The AC line current is sampled with a harmonic notch filter (72) at a plurality of n phases .THETA..sub.1 through .THETA..sub.n during each of a plurality of m cycles of the AC source (26), to provide a plurality of currents I.sub.n,m, where n is the phase and m is the cycle. The differences (I.sub.n,m)-(I.sub.n,m-x), where x is a designated number of cycles, provide a plurality of current difference signals. The absolute values of these current difference signals ID are accumulated in a synchronous summer (94) over the m cycles. An arc indicative signal is generated in response to given conditions and given combinations of conditions (116) of the cumulative absolute current difference signals ID.

Abstract: An automatic power line monitor system is disclosed for use in monitoring the electrical voltage supplied to an electrical system or appliance by monitoring the supplied electrical voltage and preventing the supplied electrical voltage from reaching the electrical system or appliance when the supplied electrical voltage is not within a predetermined range and for automatically restoring the supplied electrical voltage to the electrical system or appliance when the supplied electrical voltage is within the predetermined range.

Abstract: In a circuit arrangement to detect a voltage (U), the voltage is applied to the input of a voltage detector (VD) through a voltage divider (R1, R4), the voltage detector (VD) comprising a Schmitt-Trigger with reference voltage and an output driver. The output signal of the voltage detector (VD) is applied to the base of a transistor (T1) whose collector-emitter circuit, together with a series-connected capacitor (Cl), is connected in parallel with the voltage (U) to be detected. The junction of the capacitor (C1) and the transistor (T1) is connected to the input of the voltage detector (VD) through a resistor (R5, R6). The output of the voltage detector (VD) is further applied to the input of a component (C) delivering different output signals in dependence upon whether its input receives a constant signal level or a varying signal level.

Abstract: A detection and alarm circuit for protection of electronic components includes a fan motor current sensing resistor for producing a pulse that is amplified and introduced to a frequency-to-voltage converter for generating a filtered and processed voltage level for application to a voltage comparator. A reference voltage circuit supplies a voltage level to the comparator for matching with the filtered and processed voltage level and depending on the mismatch, an output signal is introduced to a transistor switch for operating an alert alarm device.

Abstract: In a voltage drop detecting circuit, when voltage Vcc being monitored is at a steady-state value, reference voltage B is classified by divided voltages Va to Vc from detection voltage generation circuit group for classification of reference voltage. In accordance with the result of that classification, one of the divided voltages Va to Vc from detection voltage generation circuit group for detection of a drop in the voltage being monitored is selected as detection voltage A. Since the resistance ratio can be expressed fairly correctly in ICs, the circuit structure of the voltage drop detecting circuit is capable of reducing the apparent range of variation of reference voltage B, whereby the precision of detection is improved.

Abstract: The present invention relates to an LED traffic signal light containing numerous LEDs and a voltage compensation circuit which allows the traffic light to operate over a wide range of input power voltages, while generating sufficient light intensity to control traffic at a highway intersection. The voltage compensation circuit achieves these objectives without substantially increasing the power consumption, overall cost, or failure rate of the LED traffic signal light. In the preferred embodiment, the voltage compensation circuit disables or rearranges a first and then a second set of LEDs in the traffic light, as the input power voltage drops below a first and then a second threshold voltage, so that the remaining LEDs will be driven by an increased current and generate a greater overall light intensity than if all of the LEDs were driven by the decreased current that would result from the decreased input power voltage.

Abstract: In an electric circuit supplying AC line current rent to a load (30, 31) from an AC source (26) of given frequency providing repetitive cycles, arc detection is provided by sensing cycle to cycle changes in the AC line current. The AC line current is sampled with a harmonic notch filter (72) at a plurality of n phases .THETA..sub.1 through .THETA..sub.n during each of a plurality of m cycles of the AC source (26), to provide a plurality of currents I.sub.n,m, where n is the phase and m is the cycle. The differences (I.sub.n,m)-(I.sub.n,m-x), where x is a designated number of cycles, provide a plurality of current difference signals. The absolute values of these current difference signals ID are accumulated in a synchronous summer (94) over the m cycles. An arc indicative signal is generated in response to given conditions and given combinations of conditions (116) of the cumulative absolute current difference signals ID.

Abstract: A voltage level detector circuit comprises an amplifier for amplifying the electrical output signal from a detection device, a pair of comparators for comparing the amplified electrical output signal with a respective threshold signal, wherein each comparator is adapted to change its output state when the amplified electrical output signal exceeds the respective threshold signal, and a pair of threshold processors responsive to a superimposed noise or interference component of the electrical output signal from the detection device, or of an amplified version thereof, and adapted to provide the comparators with respective threshold signals which vary with the superimposed noise or interference component, so as to maintain a relationship between the amplified electrical output signal and the threshold signal which is substantially independent of the superimposed noise or interference component.

Abstract: A monitoring system is shown to include a connector, having an input path and a current return path, for connecting a two section wrist strap to said connector, said two section wrist strap, when affixed to an operator's wrist, would complete an electrical path between the input path and the current return path of the connector across the wrist skin surface. The monitoring system further includes a current source for providing an electrical current to the input path and a comparator for comparing a voltage at the input path to a high limit value and a low limit value and for providing an alarm signal whenever the voltage at the input path is not between the high limit value and the low limit value. With such an arrangement, an operator is ensured that a proper connection between the operator and ground is maintained thus significantly reducing the possibility of an electrostatic discharge harming an electronic component handled by the operator.

Abstract: A system for continuously monitoring electrical conduction of an AC power system comprises at least one measuring module connected between two conductors of the power system. A measuring cycle is divided into two periods. During the first period, the module measures a first DC voltage component, representative of the stray DC components, applied to its terminals. During the second period, the measuring module inputs a DC current component to the power system and measures a second DC component of the voltage applied to its terminals. The difference between the second and first components is used to detect a conduction fault, the line resistance upline from the measuring module being proportional to this difference. The first and second components are obtained by computing the mean value, weighted if necessary, of DC voltage samples measured during measuring periods of a duration lower than or equal to the first and second periods.

Abstract: The contact between a device under test (DUT) and a measuring terminal is accurately judged with a simple circuit for impedance measurement. The conduction detecting means injects a judging current into the voltage terminal (L.sub.P) for low voltage. When the device under test (DUT) and both the current terminal (L.sub.C) for low voltage and the voltage terminal (L.sub.P) for low voltage are normally contacted with each other, since the inverting input terminal of the inverting amplifier is virtually grounded, and the L.sub.C and L.sub.P are substantially kept at the ground potential, the contact judgment for L.sub.C and L.sub.P is made by detecting the potentials of L.sub.P. In addition, when the impedance measurement value is larger than the predetermined lowest limit value and the current measurement value is lower than the predetermined lowest limit value, the DUT and the current terminal (H.sub.C) for high voltage are considered to have improper contact with each other.

Abstract: Aircraft systems and sensors are monitored by pre-wiring a plurality of mating connectors to each system. Each mating connector has a positive voltage pin, a zero voltage pin and a reference pin. For those systems and sensors that emit zero voltage, the system is connected to the positive voltage pin while a jumper is used to connect the zero voltage pin to the reference voltage pin. For those systems emitting positive voltage, the system is connected with the zero voltage pin while a jumper is used to connect the positive voltage pin to the reference voltage pin. For each system or sensor monitored, there is a voltage comparator having both a positive and a negative input connected with a rear-mounted connector for connection with the pre-wired mating connectors. The rear-mounted connectors have identical pin arrangements with the mating connector for proper connections.

Abstract: A rate of change comparator uses an RC charging circuit and a separate RC discharging circuit to follow a transducer output. The resistor component of each RC circuit is shunted by a diode, each biased in a different orientation so that the charging circuit charges quickly through its diode but discharges slowly through its resistor and the discharging circuit discharges quickly through its diode and slowly through its resistor. The difference in output between the charging and discharging circuits is detected with a comparator, biased off by a threshold bias voltage developed from one of the circuits. The comparator is unaffected by slow changes in transducer signals due to drift, ambient condition and similar changes because the differential voltage between the circuits is minimized for transducer signal changes below the level set by a threshold bias level.

Abstract: A circuit is described for monitoring of loads having measuring resistors in the load circuit. The circuit evaluates the measuring voltage drops obtained at the measuring resistors. The circuit comprises at least one comparator stage made up of a reference current section and a comparator section. A temperature-dependent reference current is formed in the reference current section and supplied to the comparator section, with the temperature-dependent reference current comprising a voltage-independent component and a voltage-dependent component. The comparator section comprises one or more input branches, corresponding comparator branches, and a reference branch. The comparator branch compares the reference current flowing in the reference branch with the input currents flowing in the input branches and representing a measure for the measuring voltage drops obtained at the measuring resistors and applied to the inputs of the comparator stages.

Abstract: A fault detection circuit for a plurality of DC loads uses a reference load as a benchmark. The voltages at the centerpoints of the loads to be monitored are monitored and compared with the voltage of the centerpoint of the reference load. The comparison is affected by faults which do not affect all loads equally (as by a short or open) and is unaffected by faults which do affect all loads equally (as by changes in voltage of the source).

Abstract: An apparatus for monitoring current through a lamp circuit that uses a series resistance shunt in the circuit with one end connected to a current source and the second end connected to the lamp. The apparatus includes a comparator that is connected across the shunt and has a threshold switching voltage wherein a voltage across the shunt that is larger than the threshold switching voltage will switch the comparator on and a voltage across the shunt that is smaller than the threshold switching voltage will switch the comparator off. A biasing circuit, connected to and controlling the comparator, temperature compensates the threshold switching voltage such that the threshold switching voltage changes proportionally to absolute temperature and controls a sensitivity of the threshold switching voltage to changes in a supply voltage of the circuit. In a preferred embodiment, the shunt is a portion of the printed board trace.

Abstract: A drive current for driving actuators is generated based on a first digital signal comprising n-bit binary data which is supplied from a microprocessor and it is applied to an excitation coil. The drive current is supplied to the exciting coil and is converted into a voltage which is then converted into a second digital signal comprising n-bit binary data. The binary data of the second digital signal is compared with the digital data of the first digital signal to detect an alarm condition. Furthermore, the second digital signal is compared with first and second reference value to set plural alarm conditions.

Abstract: A system is provided for monitoring signals from a linear or rotary encoder or scale to provide a warning of a malfunction of the encoder or to be able to predict a future malfunction. The system includes a feedback circuit for comparing the output of the detector in the encoder with a voltage reference and for either raising or lowering the voltage to the light source for maintaining constant maximum detected light amplitude regardless of dirt build-up on the scale with the amount of voltage correction to the light source being an indicator of the level of functioning of the encoder. The system also assures constant amplitude output signals from reflectance-type encoders in which the light source and detector are on the same side of the scale and in which the subject servo system maintains a constant amplitude reflected beam.

Abstract: An instrument for measuring voltage harmonics and current harmonics on AC (alternating current) power systems. The instrument includes the ability to determine when threshold limits have been exceeded for harmonics. The instrument also includes timing thresholds whose inputs are activated when the harmonic thresholds are exceeded. A single harmonic threshold is applied to measurements from multiple phases on poly-phase systems by comparing the square rot of the sum of the squares of measurements from each phase to the harmonic threshold. Three indicators show when voltage harmonic limits are exceeded, current harmonics limits are exceeded, or both voltage and current harmonic limits are exceeded simultaneously.

Abstract: An electrical contact avoidance device comprises an inductor plate directly or capacitively coupled to the user and coupled to a detector circuit which derives a DC signal corresponding to a voltage induced in the user's body by a radiated high voltage electrostatic field. A comparator compares the DC signal with a reference signal representing the potential difference between the inductor and reference plates, and activates an alarm if the detected signal exceeds a preselected reference level.

Abstract: A hand tool driven by a DC battery comprises a tool driving section having a motor, a DC source connected to the tool driving section, a plurality of LEDs connected to the DC source, an LED turning-off section for sequentially turning off the LEDs in accordance with the power remaining in the DC source, and an LED flickering section for causing flickering of at least one illuminated LED, when the driving section is overloaded.

Abstract: A testing device for single-pole voltage testing comprises, between a test electrode (1) and a ground electrode (2), a high impedance dropping resistor (R1) and a measurement resistor (R2) connected in series. The ground electrode (2) is capacitively coupled to earth through the body of the user. The value of the dropping resistor (R1) is at least 10 times greater than the maximum variation which occurs in the capacitively coupled reactance (C1, C2) of the user relative to the ground, so that the total impedance is almost constant. The voltage drop across the measurement resistor (R2) is amplified, rectified and compared in a comparison circuit with predetermined reference voltages in order to control a light emitting diode indicator (D2, D3, D4, D5) corresponding to the measured voltage. The test device can also be constructed for contactless voltage testing or can also be used as a continuity tester.

Abstract: A voltage detector to sense deviations of instantaneous value of a monitored voltage from a desired value is provided. The system includes a reference voltage source for providing a reference voltage. A divider responsive to the monitored voltage and the reference voltage divides the reference voltage by the monitored voltage. Thereafter a window comparator responsive to an output of the divider produces an indication when the output of the divider is either higher than some predetermined high value or lower than some predetermined low value.

Abstract: A portable resistance tester comprises a pair of regulator circuits used to drive a bridge circuit and a detector circuit when measuring the resistance values of "in-circuit" test nodes. The tester produces an audible signal when the resistance of a measured test node falls within, or without, a predetermined resistance range.

Abstract: A system for protecting an engine equipped with an electronically controlled fuel injection apparatus, in which a battery voltage is detected. When the detected battery voltage is smaller than a predetermined reference value, performance of the engine is degraded, and when the detected battery voltage is smaller than a reference value, that is smaller than the predetermined value, the engine is stopped.

Abstract: The condition of signal lamps (R1, R2) in a traffic light system is monitored by compiling a table of power consumption levels at different levels of applied voltage. The table is then used to adjust measured levels of power consumption at intervals during the service life of the traffic light system. A fault condition is signalled if the adjusted values differ by more than a predetermined amount.

Abstract: A fire detector system including ionization smoke detectors (7) is provided with improved false-alarm protection. The system includes an ionization chamber (1) with a radioactive source (10), connected in series with a resistor (2) between power supply lines (8, 9), and circuitry (11, 28) for switching the operating voltage of the ionization chamber between a normal operating value (Ut) chosen for maximized detector sensitivity, and an elevated value (Uh) for operation at current saturation. Comparisons involving the ionization currents through the ionization chamber at the two operating voltages are used not only to recognize a condition of partial shielding of the radio-active source (due to condensation, for example), but also to detect smoke under such conditions.

Abstract: A circuit including a sender providing a sender output signal responsive to a vehicle parameter, circuitry for providing an adjustable reference, circuitry for comparing the output signal to the adjustable reference and providing a comparison output signal therefrom, an up/down counter for filtering the comparison output signal, and circuitry for providing an indicator control signal in response to the filtered output signal and for controlling the adjustment of the adjustable reference, provides a signal to a vehicle operator that is both filtered and has hysteresis to minimize repeated switching of the signal between two states.

Abstract: AC line monitoring is provided for uninterruptible power supplies to detect AC power system line faults by comparing the presently received cycle of the AC power line signal with a reference waveform. The reference waveform is formed of a composite of waveforms from prior cycles which adapts over time to the shape of the AC power line waveform, so that waveforms other than pure sinusoids can be accepted without triggering false fault conditions. The composite reference waveform may be formed of essentially all samples from prior cycles with exponentially decaying weighting. An excessive deviation of the current waveform from the reference waveform results in a fault being detected which causes switching of the uninterrupible power supply to provide backup power.

Abstract: The apparatus of the invention includes a collapsible antenna for detecting the electric field associated with the individual. A current-to-voltage operational amplifier is coupled to the antenna. The amplifier includes an inverting input, a non-inverting input, and an output. A magnetic feedback path is provided for the amplifier. A magnetic filter is positioned between the amplifier output and the inverting input of the amplifier. An optical coupler is connected to the output of the amplifier. An intruder indicator, such as a signal display apparatus, a signal processor, or an audio indicator is connected to the optical coupler. The intruder indicator may simply provide a signal that an intruder is present or it may provide additional data defining the nature of the intruder.

Abstract: A temperature limit circuit has a pair of comparators for producing an output signal when a sensed temperature either exceeds of falls below a permissible range. A common impedance circuit uses a single output pin to establish both the upper and lower temperature limits and a hysteresis level at each end of the range. A hysteresis circuit includes two branches, one of which directs a hysteresis current in one direction to a hysteresis resistor at a common input to the comparators to set the hysteresis at one end of the temperature range, and the other of which directs the hysteresis current through the hysteresis resistor in the opposite direction to set the hysteresis at the other end of the temperature range; the oppositely directed current flows establish hysteresis differentials of opposite polarities. A voltage reference circuit that includes a feedback circuit is preferably used for both temperature sensing and to establish a reference current upon which the hysteresis current is based.

Abstract: An arrangement monitors a consumer in combination with an internal combustion engine or motor vehicle especially for monitoring an electric drive which is driven by an output stage in the form of a bridge circuit. Potentials are compared in the area of the consumer or of the output stage to pregiven threshold values derived from the normal operation. From this comparison, an alarm signal is generated in a time-delayed manner with the time delay being dependent upon the magnitude of the drive signal.

Abstract: A magnetic-field monitor includes a Hall sensor of the kind having a voltage reference terminal and a signal output terminal for being energized by applying a DC voltage across the output terminal and the reference terminal, and generates through the output terminal a low value current when the ambient magnetic field strength is low and a high output current when the magnetic field is high. The Hall sensor is connected via a pair of conductors to a Hall-sensor decoder circuit that is energized by a DC voltage source and in turn energizes the sensor via the pair of conductors. The decoder includes a current mirror circuit that mirrors the Hall-sensor current into a voltage divider. Three voltage comparators having different threshold voltages are connected at three points in the voltage divider.

Abstract: A programmable spike detector is designed to detect spikes in a test signal in a device under test. The spike detector includes a differential amplifier which provides a difference signal representing the difference in voltage between the test signal and an offset signal, which is the drive voltage for the device under test. A first comparator determines if the difference signal exceeds a first reference signal, and if so, provides an indication of a spike condition. A second comparator provides a second spike indication if the difference signal is less than a second reference signal. In one form of the invention, the reference signals are established under control of a programmable processor.

Abstract: A detector circuit for detecting a phase signal of a polyphase alternator for a battery charge regulator in a motor vehicle. The circuit includes differential signal amplitude discriminator means for discriminating between at least one pair of phase signals delivered by the alternator. The circuit is applicable to multifunction or to dual-purpose battery charge regulators in motor vehicles.

Abstract: Disclosed is a battery condition monitoring system that monitors the condition of batteries connected in parallel in order to determine that each battery is generating the necessary power. The system determines the difference in voltages that are proportional to the currents generated by the batteries. The system compares the voltage difference between the currents that is a positive value to a predetermined reference voltage which is the maximum allowed difference in the battery currents. If the positive difference value is greater than the reference voltage, one or more LEDs will illuminate indicating that one or more of the batteries is weak or defective, uniquely identifying the battery or batteries.