Abstract: Apparatus for use in draining, cleaning and refilling an aquarium tank including an elongated flexible hose having first and second opposite ends, a tube including an upper distal end for connection to the first end of the flexible hose, and a lower distal end adapted to be immersed in the aquarium tank such that the lower end may be placed near the bottom of the aquarium tank, a first device attachable to the second end of the flexible hose and for connection to a flowing water source for creating a flow of water from the tank through the tube and the flexible hose, and a grille, defined by a chamber and including a plurality of apertures formed in the walls thereof that are narrower than the width of the gravel particles, the grille and chamber attached to the lower distal end of the tube for contact with the gravel for moving the gravel about the floor of the tank such that the gravel particles are forced by the movement to bump and rub against each other outside the tube to dislodge the sediment and impur

Abstract: A coring circuit for an input signal in the form of a differential input current having two components in phase opposition. A first pair of cascode transistors biased by a first reference voltage applies a first fraction of each of the components of the differential current to respectively first and second resistors. A second pair of cascode transistors biased by the first reference voltage provides a second fraction of each of the components of the differential current to a differential current output of the coring circuit and respectively to first and second branches of a differential stage that also receives voltages across the first and second resistors. Two coring current sources respectively connect first and second outputs of the differential stage to a supply voltage and are connected to each other through a third resistor.

Abstract: An auxiliary video data slicer for extracting auxiliary video information from a video signal includes a peak detector. The peak detector determines a peak amplitude of horizontal sync pulses that are included in the video signal and a peak amplitude of a run-in-clock (RIC) waveform that is included in an auxiliary information component of the video signal. A variable threshold level for the peak detector is varied in a first range to detect the peak amplitude of the sync pulses. A threshold voltage for detecting the leading edge of sync pulses is derived from the peak amplitude of the sync pulses. The location of the RIC waveform within a video line interval is determined in response to detection of a sync pulse edge. The variable threshold level of the peak detector is varied in a second range to detect the peak amplitude of the RIC signal. A data slicing threshold level for extracting auxiliary video information is derived from the peak value of the RIC signal.

Abstract: An auxiliary power supply system includes an internal combustion engine driving an alternator the output of which is rectified and supplied to DC bus lines across which a storage battery is connected. The DC bus lines may supply a consuming device such as an uninterruptible power supply or telecommunications system. The voltage across the bus lines is sensed and when the voltage drops below a selected value, indicating that the consuming devices is drawing power from the battery beyond a desired limit, the engine is turned on for a period of time to warm it up, during which the power from the generator is not supplied to the DC bus lines. Thereafter, the generator supplies power to the DC bus lines to supply the consuming device and partially recharge the battery until the consuming device is no longer drawing power, after which the engine is shut off.

Abstract: An auxiliary power supply system includes an internal combustion engine driving an alternator the output of which is rectified and supplied to DC bus lines across which a storage battery is connected. The DC bus lines may supply a consuming device such as an uninterruptible power supply or telecommunications system. The voltage across the bus lines is sensed and when the voltage drops below a selected value, indicating that the consuming devices is drawing power from the battery beyond a desired limit, the engine is turned on for a period of time to warm it up, during which the power from the generator is not supplied to the DC bus lines. Thereafter, the generator supplies power to the DC bus lines to supply the consuming device and partially recharge the battery until the consuming device is no longer drawing power, after which the engine is shut off.

Abstract: In a color television receiver having first and second chroma amplifiers, a chroma overload detector uses a differential amplifier for peak detection of a chrominance signal over a predetermined threshold level, and in response thereto, for generating a control signal and applying it to the second chroma amplifier to control the gain of the amplifier.