Abstract: In an electrical load control system, an analog signal representing the actual rate of power being consumed by a plurality of loads has a nominal level when the actual rate is at a desired rate, or set point. As the level of the analog signal deviates from its nominal level, the electrical load control system functions to add or shed one or more of the loads to maintain the actual rate at the set point. During times of low power consumption, the electrical load control system may not act to optimize energy usage if the set point is not lowered. A set point control circuit is provided which senses the on/off status of one of the loads, or control load, and which provides a set point modification signal whose level represents a desired reduction in the set point and which varies in a predetermined range between minimum and maximum levels representing, respectively, no reduction in the set point and a maximum reduction in the set point.

Abstract: To maintain power consumption within predetermined limits, the ON/OFF states of a plurality of electrical loads are controlled by a digital load control circuit that forms part of a closed-loop control system. The power consumed by the ON loads is monitored and compared with a reference and in response to such comparison command signals are produced that instruct the digital circuit to add or shed loads as required, to increase or decrease, respectively, the power consumption. Inputs to the load-control circuit are in the form of one or more add or shed command pulses wherein the former instructs the circuit to add a load, and the latter instructs the circuit to shed a load. To execute these commands, the load-control circuit includes a reversible, recycling address generator that successively addresses a bank of addressable latches, one for controlling the ON/OFF state of each load.

Abstract: In a closed loop control system for monitoring and regulating the rate of electrical power delivered to a plurality of electrical loads, an improved circuit is disclosed that is responsive to an analog input signal representing a measured power rate and has a digital pulse output for conditioning a digital switching circuit to add one or more loads when the measured power rate falls below a predetermined rate and to shed one or more loads when the measured power rate exceeds such predetermined rate. The analog input signal is compared with a reference signal to produce an analog error signal that is first compensated for certain types of power rate deviations and is then fed to an analog to digital conversion circuit which includes a threshold detection circuit and a pulse generator circuit and produces one or more output pulses in response to a predetermined threshold magnitude of the compensated error signal.

Abstract: In an electrical load control system, method and apparatus are provided for selectively, individually connecting and disconnecting a plurality of loads to and from a power source. The loads are selectively connected (added), disconnected (shed), and reconnected (restored or added), in a predetermined sequence, wherein the ranking of the loads in such sequence is selectively rotated in a manner which results in a sharing of on and off time and an equalizing of wear among all of the loads. As an example of this operation, a load control system is disclosed in which the consumption of electrical power is varied by periodically shedding and adding individual loads in order to maintain the level of power usage below predetermined limits and yet make full use of the available power within such limits.