Abstract: A phase-difference detector for use with an auto-focus detecting apparatus of a camera, the detector is capable of performing an arithmetic correlation process for detecting a phase-difference at a high speed with high accuracy. This detector uses an analog correlation arithmetic device for carrying out an analog correlation arithmetic process which generates correlative values associated with a pair of analog electric signals outputted from a pair of optical sensors. An A/D converter converts the generated correlative values outputted from the analog correlation arithmetic device into digital signals. The correlation arithmetic operation is done by directly using the analog signals generated during a photoelectric conversion, and the correlative values obtained by this computation are converted into digital signals, thereby allowing the arithmetic process to be performed at a high speed.

Abstract: A method and apparatus for enhancing digital signal transmission is provided for (1) converting a digital signal to an enhanced analog signal having a specified polarity and angular velocity; (2) transmitting that enhanced analog signal from one electronic component to another electronic component; and (3) converting the enhanced analog signal back to a reconstituted digital signal. The enhanced analog signal comprises a smooth non-periodic function of voltage, current and time which preferably has the waveform of a versine function signal with specified polarity. A method of supplying power to remote locations of the apparatus for enhancing digital signals is also presented.

Abstract: A diversity receiving apparatus includes first and second antennas and circuitry for selecting one antenna or the other. Control circuitry analyzes signal strength received from the selected antenna and determines when the antennas should be switched.

Abstract: A test circuit for testing all lamps in a system monitor for a hot water heater. The comparator includes a amplifier having a reference input connected to a reference voltage and a second control input connected to power through a plurality of different circuit elements in a voltage coupling network. A timer is connected in the circuit to the control input to provide a timed drive signal to a power switch unit connected to the comparator amplifier for energizing all of the lamps. The timer is a simple resistor-capacitor network with the comparator connected to the signal control input. The signal branch circuit includes components selectively inserted to produce a test signal to the timer and comparator amplifier. A thermostat monitor is connected by a diode to the comparator amplifier and a demand for hot water creates a turn-on signal to the comparator for the period of the timer to energize all lamps for a short period at the initiation of the demand.

Abstract: The present invention is a liquid sensing device used for in determining the presence or absence of liquid in a container by the presence or absence of electrical current flow between two conductive probes. Moreover, the present invention prevents the false indication of liquid as can result from the presence of foam, or from bridging of the probes at the proximal ends thereof. A main body portion is formed of an electrically conductive material and has a probe channel extending therethrough. A non-conductive plug is inserted into the proximal end of the probe channel and provides for the retaining of a conductive probe that extends along the central axis of the probe channel. An end cap is secured to the distal end of the main body and covers the distal end of the probe channel for preventing foam access into the probe channel.

Abstract: The low battery level indicator is provided for a smoke detector. When the battery in the smoke detector becomes so weak that its voltage drops below a pre-determined value, an elongated, flexible signal member such as a tape or cord is released from the smoke detector so that it hangs down into the room below to persistently remind the occupant to replace the battery with a fresh one. The elongated signal member can be used together with a conventioanl device which emits audible periodic beeps or has a periodically flashing light to indicate the low battery condition. However, the long flexible signal member continues to hang down and remind the occupant that the battery must be replaced, even after the battery has gone completely dead and the horn and lamp no longer function. This invention constitutes a potential life-saving device.

Abstract: A plug-mounted wriststrap detector and ground monitor includes hot, neutral and ground input terminals which are connected to corresponding terminals of a power outlet when the circuit is plugged in. A jack is provided to plug a wriststrap into the circuit to provide electrostatic protection to the user. Means are provided to detect that the user is wearing the wriststrap and that the wriststrap is properly connected to the circuit as a function of whether an a.c. signal of sufficient amplitude is detected coupled to the circuit by the wriststrap and/or user. Lamps and an audible alarm warn the user if the wriststrap is not properly connected. A precision ground integrity circuit is provided to detect whether an unsafe ground condition exists and to alert the user accordingly. The ground integrity circuit uses a constant current source and voltage comparator to determine that the ground impedance does not exceed a predetermined limit.

Abstract: A circuit breaker assembly incorporating a light emitting diode as an indicator when an overload condition is present and the circuit has been blown and further wherein the assembly includes an integral, internally placed load in the form of a capacitance sufficient to energize the light emitting diode when the load normally present in the circuit has been removed. The capacitance is connected in series with the light emitting diode as well as an external ground contact for providing the ground return for energizing the light emitting diode.

Abstract: A flow sensor for detecting the absence of a minimum fluid flow in a sprinkler system. The fluid acts upon a vane positioned in the fluid path. Movement of the vane controls the position of a slider. The slider's surface has reflective and non-reflective ends which, in response to the vane's movement, reflect or absorb light from a light emission and detection means. The voltages from the light emission and detection means are monitored for indications of the fluid flow. The sensor uses a two wire signal transmitting system.

Abstract: An apparatus including a plug detector mechanism mounted adjacent an interior surface of a drain plug aperture directed through a transom of a boat. The detecting means includes a spring-biased switch positionable from an extended position in the absence of a plug to a retracted position in the presence of a plug directed through the transom. The switch is cooperative with an audible member to effect alarm in the absence of the plug.

Abstract: The two wire device tests the continuity of conductors in a monitoring circuit having an open circuited apparatus. The device has a switch which is controlled by a sequencer and a clock. Upon the application of power, the device is energized if the continuity of the conductors is present. The clock provides a train of pulses that alternately opens and closes the switch. When the switch is closed, continuity across the conductors is provided to illuminate an indicator lamp. When the switch is open, a power storage unit charges from the monitoring circuit power supply. The power storage unit provides operating power to the sequencer and the clock. The output of the clock has a long duty cycle so that the time when the switch is open is very brief, thus causing the lamp to be perceived by a human as unaffected. The sequencer counts the number of oscillations produced by the clock and when a predetermined number has occurred, turns off the clock and leaves the switch open.

Abstract: A level indicator for blood reservoirs, in particular of medical apparatus, having a level-responsive component to be provided on the wall of the blood reservoir is provided with an oscillator set to an operating frequency of greater than or equal to 50 MHz and having integrated into its circuit the level-responsive component which, when a preset limiting value is passed, changes the phase condition or amplitude condition decisive for the oscillation of the oscillator.

Abstract: A readout circuit for use with a focal plane array that employs a single transistor in each unit cell and a single capacitive feedback transimpedance amplifier to process the outputs of each column of detector elements of the array. The capacitive feedback transimpedance amplifiers extract the signals associated with the pixels along a particular row of the array. The present invention permits high performance readouts to be constructed with very little circuitry in the unit cells. Only a single minimum sized transistor switch is required in each unit cell to perform readout and reset functions for the array. In the disclosed embodiment, the readout circuit comprises an array of unit cells, each cell comprising a detector input circuit, a single transistor and a single charge storage capacitor. Row address circuits are coupled to the cells in each row of the array. A plurality of capacitive feedback transimpedance amplifiers are coupled to the cells in each column of the array.

Abstract: A reservoir, provided with a device for warning when the level of an operation fluid to be supplied to a fluid pressure master cylinder drops below a given level, comprises a fluid tank for storage of the operation fluid and a float chamber with an upper wall provided on the side portion of the fluid tank. A reed switch for the fluid level drop warning device is provided at the lower portion of the float chamber, and a float having a magnet is retained in the float chamber. A partition for restricting the movement of the float is detachably mounted at the communicating section between the fluid tank and float chamber. This arrangement facilitates the mounting and replacement of the float and reed switch.

Abstract: A peak level detecting apparatus for image sensors by which the maximum light value of a remote object is detected effectively utilizing the dynamic range of image sensors. The peak level detecting apparatus realizes a detection of the remote object patterns without any saturation in photoelectric devices by adjusting the exposure time with the detection of induced signal change in at least one of the photoelectric devices reaching the predetermined peak level, in order to improve the dynamic range and the signal to noise ratio.

Abstract: A system for automatically controlling the brightness of an optical image which is translated into digital signal samples corresponding to the pixels constituting the image includes a variable area aperture through which the image is transmitted for digitization into the samples, a device for varying the area of the aperture, a device for detecting peak values of the samples, and a device for operating the aperture area varying device until the percentage of the peak values which are above a certain peak value is a certain percentage.

Abstract: A UV exposure mointoring system for measuring UV radiation impinging on an object, the system comprising apparatus for measuring incident solar UV radiation in a weighted manner corresponding to the erythemal action spectrum of human skin, whereby the accuracy of the measurements is substantially unaffected by the amgle of incidence of incoming radiation over a wide range of angles.

Abstract: A connector has a male connecting member and a female connecting member. A monitor element comprising a resistor and a switch which are connected in series is provided in the male connecting member. The switch is provided to be opened when the connector is in a completely connected state. A monitoring circuit including the monitor element having a pair of output terminals at ends of the circuit is provided for detecting voltage across the output terminal. A change of the voltage upon the disconnection of the connector is signaled.

Abstract: A portable ground fault detector for use on tanker trucks to provide visual and audible warning of unsafe conditions. Closing of a grounding circuit operating at low voltage permits energizing of a circuit to show safe grounding conditions and interruption of continuity of the grounding circuit provides visual and audible warning of unsafe conditions.

Abstract: A television camera has an imaging device and a drive circuit. The imaging device is an interline transfer CCD further having a storing section between column of vertical CCDs thereof and a horizontal CCD thereof. The storing section having first and second vertical CCDs for receiving charges from photodiodes via the vertical CCDs. The drive circuit reads out the charges generated at photodiodes such that during a vertical blanking period of a frame, charges at the horizontal odd lines of photodiodes are transferred in response to a V SYNC pulse are transferred to the second vertical CCDs via the first vertical CCDs; then charges at even lines are transferred similarly to the third vertical CCDs; and then horizontal CCD reads charges from the second and third vertical CCDs alternately.