Abstract: A self-contained float switch for use in conjunction with water pumps and the like. The float switch operates to actuate and de-actuate such a pump at particular depths of water (L.sub.1) and (L.sub.2) which define an adjustable pumping range (R). In one embodiment the float switch consists of a cylindrical water-tight float (24) having an electrical cable (26) coming out of one end and terminating at a piggy-back plug (29) for insertion between a power output (20) and electric pump plug (18). The float contains six mercury switches (70-80) disposed obliquely to the axis of the float and equally spaced around the axis. Further circuitry including a relay (48) is provided to switch the heavier current load of the pump (12) in response to the electrical state of the mercury switches.

Abstract: A resistive fluid or boiler water type of detecting system has been disclosed. A single conductor type of probe having a plurality of conducting regions that are capable of conducting a bidirectional electric current in either a full bidirectional mode or in a unidirectional mode has been disclosed. The single probe element is capable of three separate and distinct states of operation. The first state is when there is an absence of current, the second is when there is a unidirectional portion of the bidirectional current flowing, and the third state is when the full bidirectional electric current is allowed to flow. An output device is responsive to these three states to provide different types or levels of control.

Abstract: Liquid level in tanks is gauged an can be controlled as follows. Liquid communication is provided from near the bottom of the tank to a liquid reservoir containing a liquid which is of different density and immiscible with the tank liquid. The reservoir is in liquid communication with a vertically elongated vessel having a relatively small horizontal area compared to the tank, communication being near the top of the reservoir if the reservoir liquid is less dense than the tank liquid and being near the bottom of the reservoir if the reservoir liquid is more dense than the tank liquid. The elongated vessel, which can be transparent or translucent so that the liquid level therein corresponding to the liquid level in the tank can be readily determined, can contain a float containing a proximity sensor triggering element.

Abstract: An improved system for sensing and controlling the level of fluent material in two reservoirs when material is transferred from one reservoir to the other. In electrically conducting materials, levels are sensed by direct current conduction between electrode pairs placed in each reservoir at desired "high" and "low" control levels which send D.C. digital logic sensing signals from these four sensors over connecting wires to four high resistance input circuits of a digital signal processing circuit; in electrically nonconducting materials, levels are sensed by suitable transducers which upon immersion send D.C. digital logic sensing signals to the digital signal processing circuit.

Abstract: A fluid level control circuit with a safety test function for a boiler water level probe of a fail safe type is connected to a field effect transistor controlled amplifier having a well defined threshold of operation. A safety test switch means is provided to pull the amplifier's input down below the threshold point, but not to a shorted condition. By observing the output of the system it is possible to determine whether the fluid level detector is properly installed, and whether the amplifier has had any type of unsafe operating failure.

Abstract: The Automatic Memory and Environmental Security System is a solid state electronic device to be employed in a motor vehicle for the specific purpose of closing any and all electrically operated windows, and roof panel, and locking any and all electrically operated door locks, which may have been left open or unlocked purposely or inadvertently. The system is also designed to close any and all electrically operated windows and roof panel left open when the surrounding humidity reaches 100% (the appearance of rain, drizzle, etc.). The unit is designed so that there is no interference with the normal operation of the above-named electrical device(s) after being employed in the said vehicle.

Abstract: A wireless form of humidity control for residential and other uses and comprising; a carrier current type of transmitter and receiver used in combination and within a conventional electrical wiring system for a building, said transmitter including a step-down transformer and a humidity sensing device disposed in compact and close proximity and with the latter provided in the power supply line for said transformer for intermittent actuation of said transformer and consequent minimal heat generation therefrom, said transmitter and receiver having an operating frequency of at least half again that of the carrier wiring and said receiver having capacitance in the signal receptive connections thereto sufficient to provide an impedance low enough to pass a given high frequency signal and high enough to block the line potential frequency and variations incident thereto.

Abstract: An automatic control circuit is provided for diluting a chemical concentrate in a container by the proper proportion, dispensing the mixture, indicating that the container is empty, and repeating the process. The container has a plurality of conductive probes which extend to different depths within the container. A pair of relays having contacts which control drain and fill solenoid valves in the container are controlled by the probes, depending on the level of the liquid in the container. Both visual and audible alarms are provided to indicate when the tank is empty and needs concentrate to be added thereto.

Abstract: An apparatus for monitoring and controlling the liquid level in a storage tank which involves placing at least two magnetically operated switches, e.g., magnetic-reed switches, at different levels in the tank and causing a magnet-containing float to move in response to the liquid level to activate these switches. A relay operates upon activation of the higher of these switches to start electrical current flowing to operate a discharge pump, thereby controlling the liquid level in the tank. In a preferred embodiment, a third magnetically operated switch is employed so that when the magnet activates the third switch at least one indication, e.g., sound and/or light alarm, is given that the liquid level is at least at a predetermined level.

Abstract: An amplifier system includes an operational amplifier having a reference applied to one input terminal. A voltage above or below the reference voltage is applied to the other input terminal by way of an interface circuit. The interface circuit adapts the input for use with a switch or, alternatively, the interface may be disabled to permit use of a variable resistor input such as a thermistor. The output of the operational amplifier may be a switching circuit. The amplifier system is adapted for use in a fluid level system to permit the alternate use of a switch type or thermistor level sensor.

Abstract: An electric circuit for energizing a fire-suppressing foam generator includes a switch that is opened and closed by means operated by electric control circuits, one of which contains a pair of laterally spaced lower electric probe contacts mounted in the protected area and adapted to be bridged by a rising level of foam to close that circuit. The other control circuit contains a pair of laterally spaced upper electric probe contacts above the level of the lower contacts and adapted to be bridged by a rising level of foam to close the last-mentioned control circuit.

Abstract: Apparatus for feeding compressed air to an automobile carburetor including a compressor, a compressed air holding tank, an electric air regulator control switch, a manually operated air regulator valve, a solenoid controlled flow valve, tee connections to idler jets, a cylinder and an air line connecting all of the aforesaid devices in sequence. The cylinder has a piston therein connected to a lever plate mounted on the throttle valve shaft in the cylinder of the automobile. The lever plate is connected by linkage to the accelerator pedal of the automobile.

Abstract: A solid state fluid sensitive switching member which utilizes fluid contained in a cavity to conduct the heat generated during high current switching operations away from the temperature-sensitive solid state elements of the switching member. A heat sinc tab thermally connected to the solids state elements is positioned in the cavity where the presence or absence of a fluid is to be monitored. When fluid is present in this cavity, the solid state elements which produce heat are in a closed circuit configuration and the heat sinc tab directly conducts heat from the heat-producing solid state members into the fluid being monitored. When no fluid is present in the monitored fluid cavity, the heat sinc potentials of such fluid are absent. However, in this configuration the solid state circuit elements are in an open circuit configuration and do not produce substantial amounts of heat, so that no heat sinc is required.

Abstract: A hazard prevention control circuit is provided for an electric heater having heating coils enclosed in a quartz tube immersed in a tank of solution. A circuit breaker is connected in series with a contactor coil controlling a set of contacts connecting the main lines of a power supply to the heating coils of the heater. Upon sensing a hazard condition, the control circuit causes excess current to flow through the circuit breaker to open the circuit and deenergize the contactor coil so as to open the contacts connecting the power to the heating coils. Transformers are provided for coupling power supplied by the main lines to the control circuit and the contactor coil and for coupling the pulse output of the control circuit to trigger a triac which conducts the excess current through the circuit breaker.

Abstract: A first inductive coil in the form of a bifilar winding is wound on a ferrite ring core with the two sections of the bifilar winding connected in series, the junction of the two sections forming the center tap of the coil. A capacitor is connected across the first coil to form a parallel resonant circuit therewith. The two ends of the first coil are respectively connected to a predetermined capacitance and to an electrode adapted to form a capacitative element whose dielectric includes a fluid under test. The center tap of the first coil is connected to the output of an amplifier whose input is connected to a second, detector coil comprising a separate winding on the ferrite ring core located substantially at the mid-point between the ends of the bifilar winding. The second coil is arranged to be inductively coupled to said first coil such that the mutual inductance between the first coil and the detector coil completes a feedback loop for the amplifier.

Abstract: In apparatus for monitoring the liquid level in a tank which includes a resistance bridge supplied with d-c current having two bridge arms arranged inside the tank, one of which is electrically heated, with the output of the resistance bridge followed by a signal stage with a binary indication and by a current regulator for the heating current, and a testing arrangement for simulating a given filling level, the resistance bridge is supplied from a constant current source whose current is switched from one current value to another upon the operation of the testing device in order to preclude operating disturbances during the testing.

Abstract: A leakage field capacitor has two adjacently located surface electrodes placed on an essentially plane support surface. A signal source is connected to one of the electrodes, so that this electrode, which may then be termed the transmitting electrode, will provide an electrical field which is sensed by the other, receiving electrode, which is connected to an evaluation circuit which evaluates disturbance of the field generated by the transmitting electrode. A metallic shield which is electrically floating i.e.