Abstract: A power supply system includes a plurality of power supplies having their outputs connected in parallel to provide a common voltage to an electrical load. Each power supply is self-regulating and capable of automatically turning off under power supply malfunction and overload conditions and turning back on after the condition is removed without affecting the operation of the other power supplies or interrupting the common voltage.

Abstract: In a turbine powered generating system the rate of fuel flow for auxiliary firing of a steam turbine is automatically controlled to control the generation of steam for the turbine in accordance with turbine operating parameters and system power demands. Fuel flow rates are controlled within program selected limits to minimize stresses on the steam turbine, thus increasing the performance and life expectancy of the turbine.

Abstract: A self-tuning filter is provided through the employment of a voltage tunable filter circuit which simulates a series resistor-inductor-capacitor (RLC) circuit and which is tunable to vary or adjust its resonant frequency in response to the value of an input control voltage. The filter is made self-tuning through the provision of suitable circuitry, responsive to simulated inductance and capacitance voltages, to generate the input control voltage and hence render the voltage tunable filter circuit resonant at the frequency of an applied input signal.

Abstract: A circuit for the simulation or synthesization of the equivalent voltage of a supply comprised of at least one voltage source and one impedance includes means to develop signals proportional to the instantaneous values of the voltage at the terminals of the supply and to the rate of change, with respect to time, of the current supplied to a load from the supply. The two signals thus developed are appropriately scaled and then combined to provide a simulation of the equivalent voltage of the supply.

Abstract: A generating system employing a generator having a self-excited field winding the excitation of which is achieved by supplying a bridge circuit with signals which are, respectively, proportional to the generator terminal voltage and the load current further includes means to selectively short-circuit the field winding during each cycle of normal generator operation. The system further includes a feedback path or loop for controlling the time during which the field winding is short-circuited which feedback path develops a control signal by comparing a signal representing the voltage supplied to the bridge circuit with a reference signal to develop an error signal which is then modified by a further signal proportional to the Thevenin equivalent voltage of the bridge circuit to thus linearize the feedback loop.

Abstract: A programmable data processor or controller serving as the main control in a control system contains an executive program for controlling the transfer of information between the processor and system equipment, updating that information during on-line control of the equipment and modifying the executive program to change operating parameters of the system while the data processor is controlling the system equipment. Modification of the executive program and displaying of system parameters related to the executive program and the system equipment is accomplished through the use of an operator's console which communicates with the data processor and system equipment as a result of operator intervention.

Abstract: A programmable data processor or controller serving as the main control in a control system contains an executive program for controlling the transfer of information between the processor and system equipment, updating that information during on-line control of the equipment and modifying the executive program to change operating parameters of the system while the data processor is controlling the system equipment. Modification of the executive program and displaying of system parameters related to the executive program and the system equipment is accomplished through the use of an operator's console which communicates with the data processor and system equipment as a result of operator intervention.

Abstract: A data processing system employing a pyramidal hierarchical scheme of control flow in which instruction words identifying operations to be performed include defined portions prescribing the path of control flow through the system and in which lower level elements identify to those elements in the control flow path at higher levels the ability of the former elements to perform the next in a sequence of operations.

Abstract: An adaptive filter circuit using a time modulated dead band for suppressing the effects of spurious noise associated with an error signal used in controlling a position drive motor associated with process controlling elements. The circuit includes means for restricting all signals, including both control signals and spurious noise, to a positioning motor during those periods of operation when little positioning is required. However, in those instances where a relatively large amount of repositioning is required, the system provides means for switching to a nonrestrictive mode of filtering which thereby permits maximum control over motor operation.

Abstract: A motor control circuit of the type in which the effective power supplied to the motor is controlled to govern motor operation includes a fast acting current limit circuit responsive to the motor current and operative to limit the power supplied to the motor to thus prevent excessive motor current. The current limit circuit compares a signal indicative of the motor current with a reference signal having a value which varies with respect to time and which is reset in response to prescribed control circuit conditions.

Abstract: A regulator for a direct current motor including both current limit and speed feedback paths further includes a speed control circuit for controlling a controllable power supply the output of which governs motor speed. The speed control circuit is designed to provide a desired transfer characteristic having extremely high gain at low frequencies while maintaining a substantially unity gain at higher frequencies to thereby enhance the stability of the motor operation throughout a wide range.

Abstract: In a turbine powered generating system the rate of fuel flow for auxiliary firing of a steam turbine is automatically controlled to control the generation of steam for the turbine in accordance with turbine operating parameters and system power demands. Fuel flow rates are controlled within program selected limits to minimize stresses on the steam turbine, thus increasing the performance and life expectancy of the turbine.