Abstract: A new method and apparatus for recursive parameter estimation which closely approximates actual values is taught. Briefly stated, the within invention estimates impedance parameters of network branches in both on-line and off-line modes, providing accurate estimation of branch parameters in the presence of noise in measurements and rejecting gross measurement errors, by use of a Kalman type Markov filter scheme using maximum likelihood estimation.

Abstract: A flash-on reduction circuit for use in the binary state output circuitry of an industrial controller employs a current conductor to charge parasitic capacitances of the output circuitry when the industrial controller is first turned on and a current limiter for preventing high current flows through the output power stages of the output circuit when the industrial controller is first turned on. The current limiter is deactivated by a timing means after the parasitic capacitances have been charged by the current conductor. In a first embodiment, the current conductor and current limiting means are provided by a current source applying increasing power to the output circuit.

Abstract: The invention relates to a fault recognition circuit for at least two power supplies feeding in parallel a user at an output side. The power supplies each have an electronic switch, a power transformer and a rectifier portion with a following filter element. In order to achieve short repair times, the respective down power supply is immediately identified after the outage of one of the parallel power supplies. For this purpose, a current transformer is provided which lies between the electronic switch and the power transformer. The load voltage of the current transformer is supplied to first a rectifier unit and the ac voltage component of the unfiltered dc voltage at the rectifier portion of the power pack units is supplied via a high pass filter to a second rectifier unit. The outputs of the rectifier units are connected to inputs of first and second comparators, and the other inputs of the comparators are connected with comparison voltages.

Abstract: A comparator for sensing a small voltage differential at, or close to, the operating voltage rails includes first and second means for producing first and second currents and for producing a third current which is indicative of the difference between the first and second currents. The first current varies as a linear function of first (e.g. V.sub.IN) and second (e.g. V.sub.O) voltages, the amplitude of the first current being proportional to that one of said first and second voltage having the largest amplitude. The second current varies exponentially as a function of the difference between the first and second voltages. Comparator means embodying the invention are particularly useful in circuits where a transistor-switch couples an input voltage (V.sub.IN) to an output terminal and the transistor-switch is to be turned-off when V.sub.IN drops below the voltage (V.sub.O) at the output terminal.

Abstract: Apparatus can limit power by limiting the duty cycle of current carried by a pair of lines. The lines intermittently conduct electrical power. The apparatus has a clock, a converter and a switch system. The clock can provide a timing signal. The converter is driven by the lines and can convert its intermittent electrical signals to uninterrupted power and can supply this uninterrupted power to the clock. The switch system responds to the timing signal and can periodically interrupt at least one of the lines.

Abstract: An energy conservation schedule is followed automatically in response to production activity in a plant facility. The demand of power from the utility company is used as an indicator of actual production activity. The ON/OFF ratio of non-production loads is reduced to conserve energy and such adjustment is automatic in relation to actual demand of power. In one embodiment of the invention, a higher level of constraint is imposed on the non-production loads as soon as the demand has passed a critical threshold downward. In a second embodiment of the invention, control of the demand is installed in the plant in order to meet a demand limit at the end of a period of control involving the production loads as well as non-production loads under constraints. In the latter situation, whenever demand control is ineffective for a full control period to affect switching of the production loads, the system goes to energy conservation with a higher level of constraints applied to the non-production loads.

Abstract: The supply of power to cyclical, separately controllable loads is controlled without interrupting the operating cycle of the loads. A controllable power supply switch interrupts the power supply circuit to the load only when signalled by a load cycle switch. A power demand monitor and limiter senses the total power being consumed by all of the loads, and generates signals indicating that the supply of power to one or more of the loads is to be interrupted when the total power consumed approaches a given maximum. A load cycle switch generates a signal when an operating cycle of a load is completed. A load gate allows the power demand monitor and limiter to pass a control signal to the power supply switch to cause it to interrupt the power supply circuit to the selected load, only after the load gate has received a signal from the load cycle switch indicating the completion of an operating cycle.