Abstract: The cycles of an oscillator varying in frequency in proportion to the changing level of a monitored liquid are counted over a fixed period of time. A derived submultiple of the count is compared relative to an electronically stored table of numbers indicative of known liquid levels. Predetermined relationships between the count and the table initiate control functions for maintaining or varying the level of monitored liquid during a programmed series of operations such as, for example, the programmed cycles of a microcomputer controlled clothes washing machine.

Abstract: An automatic washing machine which automatically carries out the steps of washing, rinsing and dehydrating in accordance with a preselected program, comprises an indication means for indicating the occurrence of abnormal operation if it occurs in the steps of washing, rinsing and dehydrating, in such a manner that the indication mode differs from cause to cause of the occurrence of the abnormal operation.

Abstract: The liquid level within a storage tank network is continuously monitored by a transducer system of the present invention formed essentially of MSI's (Medium Scale Integrated Chips) including a differential pressure (dp) cell in circuit with a digital volt meter (DVM) which, in turn, is connected to a series of look-up ROM's (Read-Only Memories). In operation and as a function of dp cell output level, DVM is continuously applying BCD signals to the ROM's, such signals being proportional to liquid level. The ROM's retain, in memory, the Gray code translations of the BCD input. The ROM's are then periodically accessed via an analog multiplexer controlled by an oscillator/ripple counter to provide corresponding microcircuit level signals at the output of a 7-segment decoder/driver. Thereafter, the microcircuit signals are regenerated--at levels compatible with conventional MARK-SPACE tank gauging systems--using an isolation/driver network in circuit with the 7-segment decoder/driver.

Abstract: A liquid level sensing apparatus includes a housing having disposed therein circuit means and a power source for providing an indication when the liquid on a surface reaches a predetermined level. The sensing device which activates the circuit means is a disposable liquid disruptable fuse link fabricated from porous paper mounted on the arm portions of a spring means capable of activating the circuit means.

Abstract: The liquid nitrogen level in a flask is controlled by the degree of immersion of two sensing coils of copper wire in the liquid nitrogen activating a solid state switching circuit which controls a liquid nitrogen inlet flow valve. Manual override and sensor fault indication is provided.