Abstract: An improved circuit breaker with overload condition illuminated indicator having a secondary switch coupled to the movement inherent in conventional circuit breaker levers. The improved circuit breaker is self-powered with batteries thereby insulating itself from possible power failures.

Abstract: An electro-optical circuit for detecting fluid in a translucent or a transparent duct or tube, this circuit including an AC activated light emitting diode (LED) for transmitting a narrow beam of light through the tube and a photo transistor detection, sub-circuit activated by the LED light beam, the power to the LED being adjusted to operate the photo transistor of the detection circuit in its unsaturated, active region of operation.

Abstract: A portable industrial toilet cabin is provided with a smoke-sensitive alarm unit for detecting smoking by an occupant of the toilet and emitting an alarm signal responsive thereto. The unit is useful, for example, in industrial and like areas where smoking is a hazard and is therefore prohibited. The unit may be mounted around a purpose-formed opening in an inclined roof of the cabin by a specialized adapter that mounts the unit in a horizontal disposition, and which may include a security screen for preventing occupants of the toilet from tampering with the alarm unit.

Abstract: A method and device for continuously analyzing, retaining and periodically displaying the concentration of a selected component in an emission gas from a vapor recovery unit. A timing device is provided to periodically display the average concentration of the component in the off gas and the concentration is continuously monitored and supplied to first and second level alarms to be actuated at selected concentrations of the component where when the concentration reaches the first level the concentration is displayed and where if the concentration reaches the second level the vapor recovery unit may be shut down.

Abstract: A detector system for sensing the presence, or absence, of electrically-conductive liquid in contact with two probe members. The system includes switchable voltage sources to selectively establish a potential across capacitors connected to the probe members, and detection systems for sensing the magnitudes of charges on the capacitors. The magnitudes of the sampled charge at given intervals is indicative of the presence, or absence, of ionic liquid in contact with the probe members.

Abstract: A circuit for monitoring the status of electrical signals, such as those present on the control and data lines of an RS-232 interface, includes a single operational amplifier and a dual-color LED indicator. The electrical characteristics of the LED's form a significant part of the circuit parameters. The monitor design provides a predetermined circuit input impedance and positive/negative switching thresholds to effect the selective illumination of the LED's.

Abstract: A sensor apparatus cooperates with an electrical system capable of delivering power to and receiving signals from the sensor. A cable housing insulated wires is connected to the sensor and disposed in proximity to a fluid possibly containing a corrosive impurity. Corrosion detecting elements are connected to the wires and are immersed in the fluid possibly containing the impurity. Further, the elements are provided with breakable regions fabricated to corrode in the presence of the corrosive impurity. To facilitate fracture, the elements are loaded in tension so the breakable regions will fracture rapidly in the presence of corrosive impurities, to thereby send an electric signal to remote electrical equipment to indicate the presence of at least one impurity.

Abstract: A wet cell battery monitor developed to monitor both electrolyte fluid level and electrolyte fluid charge (specific gravity) of a single cell. The monitor includes a probe and appropriate circuitry. The probe is adapted for insertion into a cell for monitoring and is connected to two circuits which are interconnected. Both include resistors, preferably variable, and include induction coil type relay switches. Blocking diodes are preferably used to maintain the independent integrity of each of the two circuit, one which warns of fluid level drop off and the other of a decrease in electrolyte fluid charge. The two circuits each drop off independenly in response to specific gravity (state of charge) and to fluid level, respectively, setting off alarms, e.g. visual or audio signals.

Abstract: A smoke alarm mounted atop a Christmas tree, where an early indication of an impending fire may be generated. The alarm has built-in ionization chamber for smoke detection, control circuits for operating the ionization chamber and circuitry for processing and interpreting the output signals from the ionization chamber. In case of smoke detection, the control circuit operates a loudspeaker to generate a loud audible signal. The smoke alarm also has provisions for mounting atop a door. In an expanded version, the smoke alarm incorporates an intrusion alarm that is connected with a vibration detector with control circuits that operates the loudspeaker to produce a loud audible signal in case of tampering with the door. The alarm has provisions for self-checking the status of the built-in batteries and a light indicator shows if the batteries need replacement. A manual push button provides means for testing the smoke.

Abstract: An emergency response system in which the low battery condition of a wireless help unit is automatically detected and indicated at a receiver. The help unit provides, as part of the transmitted signal, a signal indication of battery condition. The received signal is decoded and, upon detection of a low battery signal indication, a visual and/or audible output indication denotes this condition. The low battery indication at the receiver remains on until a transmission is received from the help unit when containing a fresh battery replacement.

Abstract: A soil pollution monitoring system includes a plurality of ducts for conveying gases and air past a sensing device. The sensing device detects selected compounds in the gases and air and provides an output in electrical form which indicates whether or not the levels of certain compounds in the gases and air are greater than a threshold amount thereby indicating that a leak has occurred.

Abstract: In a pressure measuring system which includes a pressure transducer for generating an analogue signal as a function of pressure, circuitry for generating a non-linear error signal as a function of the difference between the input signal and a feedback signal, a feedback circuit which generates the feedback signal as a function of said error signal to null the error signal and generates a digital output signal as a function of the pressure, a pressure surge detecting circuit having an amplitude detector connected to said pressure measuring system to receive the error signal and generating an output signal when the error signal is equal to and greater than a predetermined magnitude; a timer circuit connected to receive said output signal and generate an alarm signal when the output signal continues for a predetermined period of time, a digital computing circuit connected to receive the digital output signal for computing the rate of change of pressure and the change in pressure, a memory circuit storing predete

Abstract: A system for monitoring a battery voltage level and A.C. power supply. The A.C. power supply and a backup battery are used to power a voltage regulator which provides a reference voltage to the system. A first comparator circuit senses a drop of the voltage from the monitored battery below a predetermined level and provide a signal in response thereto. A second comparator circuit senses the loss of A.C. power and produces a signal in response thereto. A backup battery provides power to the system in the event of the loss of A.C. power. The signals produced by the comparator circuits activate a timer which in turn activates an alarm to indicate a problem in the system. The timer may be automatically deactivated by a return of the battery voltage level above the predetermined value to prevent false alarms. A second timer is also provided to provide deactivation of the alarm during servicing of the system. The system is designed so that the alarm will be sounded in the event of loss of A.C.

Abstract: An emergency light and smoke alarm system comprises a smoke detector mounted in a housing for detecting smoke and producing an audible and visual signal in response to the detected smoke. A flashlight is mounted on a bracket provided on the housing such that a portion of the bracket physically and electrically separates the battery terminals of the flashlight at their normal interface. When the flashlight is removed from the bracket the battery terminals are pushed into contact by a spring which turns on the flashlight.

Abstract: This invention is a smoke or fire detector that first utilizes a signal that is indicative of a detected smoke or fire condition to operate an air moving device to purge the detectors photocell or ionization chamber and to thereafter allow an additional signal indicative of a detected smoke or fire condition within a predetermined time frame to provide an alarm signal. The smoke or fire detector avoids many false alarm situations by placing a cyclic purge switching control system between the smoke or fire detector and the alarm signal device. The cyclic purge switching control system sequentially connects the signal indicative of a detected smoke or fire condition between the air moving device such as a fan and the alarm signal device.

Abstract: A micropower DC voltage indicator is provided that is a two terminal device with a very high input impedance. An oscillator circuit is provided by a series of inverters, such as metal-oxide semiconductors (MOS) with the power inputs connected in parallel. A suitable RC circuit connects the output of one MOS inverter to the input of another MOS inverter, otherwise the output of each MOS inverter connects directly to the input of the next MOS inverter. Across one of the MOS inverters is connected a liquid crystal display which indicates if a DC voltage within a specific range is applied to the two terminals of the DC voltage indicator. The two terminal inputs to the oscillator circuit have a very high impedance and operate over a fairly broad DC voltage range.

Abstract: The invention provides an apparatus and method for monitoring the volume of material loaded into a truck body. Apparatus is provided for sensing the volume of material held in the truck body and indicating, visually or audibly, when a predetermined volumetric loading has been accomplished. Such an indication informs the appropriate personnel that, if the material being loaded is of high density, loading should be stopped. Several different embodiments for the sensing apparatus are disclosed, one of which is a plurality of horizontal holes in the side of the truck body located at a level corresponding to the maximum loading level for a high density material. A cover plate is provided for covering these holes when not being used as a horizontal sight gauge for monitoring the volume level of the material being loaded. Each of the plurality of holes includes a mechanism for preventing material flow through the holes when the cover plate is lowered to expose them to view for use as a horizontal sight gauge.

Abstract: A compact case houses a battery powered smoke detector, and an alarm clock is detachably mounted to the case. A mechanism is provided for releasably securing the case to the upper edge of a door, picture frame, or the like, so that the smoke detector is positioned close to the ceiling of a room where it more effectively detects fire. The detachable clock is removed and placed at a more convenient location apart from the smoke detector, for example, on a table in the room. A three-position switch is provided. In one position, the switch cuts off power to the smoke detector to prevent unwanted alarms. In another position, the switch causes an emergency light to turn on while the smoke detector is simultaneously deenergized. In the third position, the switch couples the light to the smoke detector circuit and engages this latter circuit such that the light automatically turns on when the smoke detector alarm sounds.

Abstract: A magnetically actuated illuminating warning device for conventional circuit breakers of the type that have a switch assembly with three possible positions for its switch lever. A battery powered illuminating device is mounted in the vicinity of the breaker and the illuminating circuit is interrupted by a magnetically actuated switch that is closed when a permanent magnet mounted on the switch lever comes within a predetermined distance. The position of the magnetic switch is selected so that it is actuated or closed when the switch lever is in the overload position.

Abstract: A fluid level sensor utilizes thick film thermistors in a four-thermistor bridge configuration. The bridge is heated by a heater to sense the presence or absence of fluid at a particular level with respect to the thermistors. Upon energizing the bridge with a power source, the middle leads thereof are monitored for voltage separation and polarity. An indicator circuit indicates when one or more of the thermistors is submerged in the fluid. The heater influences the temperature of the thermistors to a greater or lesser extent depending upon whether or not they are submerged. Detectable changes in voltages across the bridge are accordingly produced.