Abstract: A rotor disk or color wheel received on a shaft to be sensed has an annular band of dual color (red/green) filter material having opposite circumferential gradient. A printed circuit board on one axial side of the rotor disk has the dual color LED, emitting light to a reflector on the opposite axial side of the rotor disk. Some reflected light from the LED passes through the filter which transmits, according to the amount of single color filter material present at the particular rotor station to a photodetector on the circuit board. Other rays of the emitted light are reflected directly to a second detector for ambient compensation. The amount of light transmitted by the filter causes the detector current to vary the charge rate of a capacitor charged to a reference level, and when reached the LED is switched to the other of the dual color emission.

Abstract: A planar transformer having windings on a printed circuit board coupled by a high frequency ferrite core driven by a high frequency operational amplifier based relaxation oscillator controlling a switch for pulsing a primary winding of the transformer at a set frequency. The secondary of the transformer powers a lamp circuit which is isolated from the electrical supply, and a test input is connected in a logic OR arrangement with the electrical supply.

Abstract: In an electro-optic voltage transducer utilizing a crystal exhibiting birefringence in a fast axis and a slow axis mutually orthogonal to an optic axis in the presence of an electric field produced by the voltage to be measured, the crystal is mounted for angular adjustment relative to the direction of propagation of a light beam passing through the crystal and polarized at an angle to the fast and slow axes to provide adjustment of the effective half-wave voltage of the crystal. Preferably, the crystal is a disk mounted for rotation about an axis perpendicular to the optic axis by temperature sensitive mounts extending perpendicular to radii of the disk in order to provide temperature compensation. Greater angular adjustment, which extends unambiguous voltage measurement above the natural half-wave voltage of the crystal, is provided by securing the temperature responsive mounts to a rotatable support disk.

Abstract: A transducer housing for mounting a port in a combustion chamber has a metal diaphragm exposed to the combustion gasses. The pressure of the combustion gasses deflects the diaphragm which locally deflects a simply supported beam. The beam is formed of refractory material having epitaxially grown crystalline piezoresistors formed on one surface of the beam and connected in a bridge circuit. Noble metal foil leads connect to the piezoresistors to form the bridge and provide attachment pads. The pads are noble metal welded to other noble metal foil pads provided on a ceramic substrate to form a sensor subassembly for mounting adjacent the diaphragm to form a transducer.

Abstract: Direct current can be measured by passing a conductor carrying the current through the core of a toroidal transformer having a bias winding and a sensing winding. A pulse generator send pulses of magnetization current through the sensing winding so that the magnetization current produces a magnetic flux in the core which opposes a magnetic flux produced by the direct current carried by the conductor. A sensing circuit, connected to the sensing winding, detects the level of current through that winding to produce a measurement of the direct current carried by the conductor. A constant direct current is applied through the bias winding to increase the magnetic flux produced by the direct current carried by the conductor. Biasing the magnetic flux enables even small currents flowing through the conductor to be measured. Another version of the current sensor uses two transformers to measure direct current flowing in either direction in the conductor and provides an indication of that current's polarity.

Abstract: An electric current is measured by a device that includes a magneto-optical element which acts as a Faraday rotator wherein a plane of polarization of polarized light passing therethrough is rotated as a function of a magnetic field surrounding that element. A light emitter and polarizer send a polarized light beam through the magneto-optical element. First and second light detectors are located within the single beam of light emerging from the magneto-optical element. Associated with the two detectors are separate polarizers respectively oriented at -45 degrees and +45 degrees to a polarization plane of the light beam emerging from the magneto-optical element when no electric current flows through the conductor. The magnitude of the current in the conductor is determined by comparing signals from the two light detectors.

Abstract: A system for photoelectrically sensing the color of an object includes two or more light sources having different characteristic ranges of chromaticity and one primary photosensitive element which receives light from the light sources after it has reflected off of the target object and a secondary photosensitive element which receives light from the light sources prior to reflection off of the target. A divider element divides the output of the primary photosensitive element by the output of the secondary photosensitive element to automatically align the signal representative of the color of the object for variation in the light power output of the light sources. In an alternate embodiment, the output of the secondary photosensitive receiver is used as a closed loop feedback signal to regulate the light power output of the light sources.

Abstract: At least one pair of light emitting diodes (LEDs) is disposed to direct a beam of common discrete chromaticity each to a separate target area located at different distances from a centrally disposed photodetector. Upon pulsing of the diodes at a common time, the photodetector receives the sum of the diffused light reflected from a target disposed at a location between the separate target areas to substantially reduce the affects of variation in distance of a target from the photodetector. The photodetector output is corrected for the effects on the LEDs of variations in ambient temperature.

Abstract: An optical displacement measuring system including a PSD, position sensitive device, and having a pair of outputs providing electrical current I1 and I2 satisfying the equation ##EQU1## where x is the position of a spot of light along a surface of the PSD reflected by a target from a light source which in turn gives the target distance by triangulation. A ramp generator U1A periodically generates an increasing ramp voltage periodically energizing the light source LED1 to pulse the light source between on and off states. A comparator U10 compares the Sum I1+I2 against a given threshold as the sum I1+I2 increases with increasing ramp voltage. Subtraction circuitry, U7 and U8B, samples I1 and samples I2 when the sum I1+I2 reaches the given threshold, and outputs the difference I1-I2 to provide a measure of x.

Abstract: An adjustable frequency ON/OFF delay circuit 2 is provided by ON and OFF delay counters 6 and 14 and respective adjustable frequency oscillators 4 and 20. The ON delay counter 6 is enabled by an input ON signal and clocked by its oscillator 4 to a given count for outputting a delayed output ON signal. This counter 6 is disabled by an input OFF signal and outputs the OFF signal without delay. The second counter 14 responds to the first counter 6 for outputting the delayed output ON signal without further delay, and for delaying the output OFF signal. Circuit 2 is ideal for proximity switch applications, particularly photoelectric type proximity switches, for providing a delayed output signal following a given sensed condition.

Abstract: A delay circuit 2 utilizes two comparator timers 4 and 6 and a minimum of logic to achieve a combination ON/OFF delayed function. The comparator timers 4 and 6 are resettable independently of each other such that each respective ON or OFF delay function may begin retiming without waiting for the other delay function to time out if the input signal transitions back and forth before the end of the respective ON or OFF delay. The delayed circuit 2 is ideal for proximity switch applications, particularly photoelectric type proximity switches, for providing a delayed output signal following a given sensed condition.

Abstract: A one-shot delay timer 4 is provided by a pair of comparator timers 14 and 18. The first comparator timer 14 responds to an input signal and provides a delayed output initiating the output pulse. The second comparator timer 18 provides a delayed output terminating the output pulse. The delayed output pulse of controlled length is generated for each input signal except when a second input signal occurs before the termination of the one-shot output pulse. The delayed output pulse is generated regardless of the duration of the input signal, even if the input signal lasts longer than the termination of the output pulse. Timer 4 is ideal for proximity switch applications, particularly photoelectric type proximity switches, for providing a delayed output signal following a given sensed condition.

Abstract: An adjustable frequency oscillator 2 is provided by a comparator timer 4 having a potentiometer 6 at its output 8 for concurrently changing both charging current and threshold trip voltage to control the frequency of oscillation of the comparator output. The oscillator is ideal for proximity switch applications, particularly photoelectric type proximity switches, for timing a delayed output signal following a given sensed condition.

Abstract: A comparator timer 2 is disclosed in which charging current and threshold trip voltage are both adjusted with a single potentiometer 6. Moving the pot wiper 8 in one direction increases the threshold trip voltage at the reference input terminal 12 of the comparator 4, such as the minus terminal of an operational amplifier, and at the same time decreases the capacitor charging current to the comparing input terminal 16, such as the plus terminal of the op amp, to lengthen the timing interval. Moving the pot wiper 8 in the other direction decreases threshold trip voltage and concurrently increases capacitor charging current to shorten the timing interval. The circuit affords expanded timing range, reduced power consumption and improved adjustment resolution, which are ideal for proximity switch applications, particularly photoelectric type proximity switches.

Abstract: A transistor circuit (18) is series connected with a solid state switching device (14) and a load (4) controlled by that device (14) to protect that device (14) from overcurrents resulting from short circuits such as across the load (4). The transistor circuit (18) detects the overcurrent and switches to a high impedance state in response to that detection. The circuit (18) is self-resettable to restore to the low impedance state each half-cycle of applied voltage, thereby to automatically restore the switching device (14) to normal operation immediately upon removal of the short, and is set to initially respond to a level of current sufficiently high to preclude switching in response to inrush currents. Initial switching of the circuit (18) to its high impedance state latches a reduced level detection circuit (R1-R2-Q4) in the transistor circuitry (18) whereby the latter switches to its high impedance state upon detecting lower overcurrent values for each successive half-cycle until the short is removed.

Abstract: A universal 3-wire switch module is provided for normally open and/or normally closed load control modes. The universal switch module is field convertible from P type DC to N type DC to P type AC to N type AC configurations as programmed by installation wire connection, without internal changes to the switch module. A single switch module replaces the prior dedicated switch modules used for the various configurations. The switch module is further characterized by its versatile application to a wide range of voltage.

Abstract: A circuit for a switch which receives an input from a sensor head (18) such as a proximity sensor, limit switch, or other type of condition-responsive sensor. In its most complex form the circuit includes a power supply/regulator (24), an output load current source (12), an output load current sink (14), input logic (16) to receive the signal from the sensing head, a selector (10) to determine whether the source and sink will be normally open or normally closed, and a device (26) for checking the outputs for faults and indicating the presence of such. Other circuits include certain combinations of these parts or variations of these parts.

Abstract: An on-delay timer of the solid state type incorporating integrated circuit (IC) modules including a five-transistor array in a dual-in-line package (DIP), a multiple-transistor monolithic triggering comparator circuit used as a timer, and a bidirectional thyristor or Triac. All voltages are referenced to one power line to afford simplicity of circuitry wherein the load current does not flow through the pilot switch. A leaky switch detector circuit using a simple voltage divider is incorporated in the pilot switch circuit.