Abstract: A rapid increase in motor current (di/dt above a predetermined threshold) causes the motor control system to enter pulse mode operation in-which the motor current is pulsed on and off rapidly to dislodge the workpiece obstruction or binding condition that would otherwise lead to a motor stall. When the workpiece obstruction or binding has been cleared, the motor resumes normal operation.

Abstract: A programmable system controller is disclosed which is particularly suited for monitoring a correctly responding to user commands initiated by telephone and switch activations. The switch activations may be generated by switches of the two or three wire maintained type or momentary switches. The switch inputs are routed to a switch conditioning circuit that compensate for such problems as switch bouncing or noise levels associated with the switches. The telephone commands, in the form of an electrical signals, are routed directly to the programmable device of the system controller. The programmable system controller comprises the programmable device which responds to the switch conditioning circuit to determine the particular type of switch generating the switch command and the validity of the switch command. The programmable device in response of the valid commands and telephone commands provides a digital quantity to a sequencer, which, in turn, activates output devices such as one or more banks of relays.

Abstract: A voltage surge suppression circuit for a low voltage coaxial cable comprises a gas tube connected across the signal and shield conductors and an MOV connecting the shield conductor to a ground. In the case of a balance signal line comprising two conductors, a first gas tube connects one line to ground and a second gas tube is connected across both conductors. A third gas tube may connect the other conductor to ground in which case the second gas tube may be optional. The ground is preferably a ground associated with a power line voltage surge suppression means.

Abstract: A voltage surge suppression circuit employs two series connected metal oxide varistors and a power interrupter to provide suppression of all modes of voltage surge while providing protection against failure of either metal oxide varistor. An indicator is provided to indicate the status of the circuit to the user.

Abstract: A power supply for providing multiple operating potentials to a load switching controller is capable of providing constant voltage d.c. outputs from any of a plurality of a.c. voltage sources including the full range of power supply voltages and frequencies commonly used in various geographic locations throughout the world. The power switching element on-time is controlled by sensing the output voltage levels and providing feedback control of the switching element. A status circuit provides an indication of either an overvoltage of an undervoltage condition.

Abstract: In a retrofit dimming installation for a fluorescent lighting system with a conventional ballast, filament power is maintained, even when the lamps are dimmed, by providing a high frequency component to the ballast voltage. The selected high frequency component allows heating of the filaments without adding to the light output of the lamps, thereby practically eliminating the shortened lamp life usually resulting from operating the lamp in a dimmed condition.

Abstract: An improved switch input arrangement for a system that remotely controls distributed electrical loads. The switch input arrangement is part of a transceiver decoder that receives commands from central controller for controlling the state of latching relays for controlling the power circuits of the loads. The improvements include: monitoring the state of contact closure inputs to the transceiver decoder, selectively enabling/disabling specific contact closures to control the masking of switch inputs, inclusion of an accumulated switch buffer to store the last actuation state of all relays, an answerback to insure that action occurs responsive to a switch input, a shifting threshold and multiplexing technique for more accurate reading of contact closure switch inputs, and the inclusion of a power-up reset message annunciated to the central controller to alert it that certain commands may have to be issued in order to reestablish the desired states of the transceiver.

Abstract: An improved relay actuating processor for a system that remotely control distributed electrical loads. The relay module is a part of a transceiver decoder that receives commands from a central controller for controlling the state of latching relays for controlling the power circuits of the loads.

Abstract: A clear channel detector for use in a binary digital data transmission system in which collisions are possible between simultaneously transmitting stations all connected to a common transmission medium. The detector receives the output from each of a pair of different binary symbol detectors in the station receiver. The voltage difference between the binary symbol detector outputs is amplified, and the resulting bipolar voltage is converted to an absolute amplitude. After further amplification, a threshold adjustment is provided at a trigger subcircuit having at least one output signal indicating the presence of a clear transmission channel which is not presently in use.

Abstract: In a digital data communications system having a plurality of slaved data transceivers transmitting data to, and receiving data from, a master station, the master station classifies a received signal, in each of a multiplicity of bit time intervals, as one or the other of the pair of binary signal states. The received binary signal state is echoed to all of the slaved stations, to cause those stations which did not previously transmit that binary state to cease transmitting data. Those slave stations which transmitted the echoed previous bit binary state then transmit the next bit of data, which is again echoed. Slaved stations receiving bit echoes which are different from the previous bit sent will know that there has been a collision and that the master station did not receive their bit of data, whereby the number of slave stations transmitting is reduced, in successive bit time intervals, until only one slave station remains transmitting.

Abstract: A power supply, for providing operating potential to a load switching controller, is connected in series between an A.C. source and at least one power-consuming load, and in parallel with the controller to which operating potential is provided. The power supply operates by connection of the source to charge an output capacitor only during a single polarity half-cycle of the source; the connection is terminated when the output voltage, across the capacitor, reaches a predetermined magnitude.

Abstract: Intelligent load control and switching circuits for facilitating the switching and control of the power consumption level of at least one power-consuming load, responsive to a signal, having a programmable amplitude or programmable pulse-width, provided thereto. The load control and switching circuit not only controls the coupling of a power source to a power-consuming load, but also controls the portion of the source waveform cycle during which the load is coupled to the source, to control the average power consumption thereof. Several embodiments of load control and switching circuitry, as well as power supplies for providing operating potential thereto, as disclosed.

Abstract: Apparatus facilitating the switching and control of the power consumption level of at least one power-consuming load remotely located from a central facility. Load switching and power-consumption control commands are sent from the central facility to each of the remote locations to provide an analog signal having a programmable amplitude or programmable pulse-width thereof to an intelligent load control and switching circuit. The load control and switching circuit not only controls the coupling of a power source to a power-consuming load, but also controls the portion of the source waveform cycle during which the load is coupled to the source, to control the average power consumption thereof. Several embodiments of load control and switching circuitry, as well as power supplies for providing operating potential thereto, are disclosed.