Abstract: A vehicle charging and selection system for kiosk operated electrical vehicles. The system includes a utility connected AC charging source, a battery-to-battery DC charging source, a number of vehicle charging stations, a local power bus connectable to both charging sources and each of the charging stations and a system controller connected to each of the charging stations. The system controller evaluates the vehicle battery condition of each electric vehicle connected to one of the charging stations and determines the most efficient method for charging the largest number of vehicle batteries based on current condition of the individual batteries, weather conditions, time of day, status of the utility electrical grid, etc. The system controller also selects one of the connected electric vehicles for customer use by using the battery charging information and additional information about the desired trip provided by the customer and other external data sources monitored by the system controller.

Abstract: A vehicle charging and selection system for kiosk operated electrical vehicles. The system includes a utility connected AC charging source, a battery-to-battery DC charging source, a number of vehicle charging stations, a local power bus connectable to both charging sources and each of the charging stations and a system controller connected to each of the charging stations. The system controller evaluates the vehicle battery condition of each electric vehicle connected to one of the charging stations and determines the most efficient method for charging the largest number of vehicle batteries based on current condition of the individual batteries, weather conditions, time of day, status of the utility electrical grid, etc. The system controller also selects one of the connected electric vehicles for customer use by using the battery charging information and additional information about the desired trip provided by the customer and other external data sources monitored by the system controller.

Abstract: An economical digital voltage sag compensator for overcoming sags in distributed electrical power. The voltage sag compensator employs an inexpensive micro-controller, a full wave bridge rectifier, a DC power supply, a voltage divider and an output switch. The micro-controller continuously monitors and evaluates, with respect to a setpoint measured in volt-seconds, the rectified DC voltage. At regularly spaced trigger events, as determined by the micro-controller, the micro-controller concurrently monitors the rectified DC voltage, evaluates the monitored voltage with respect to the setpoint, produces an output signal and sends that output signal to the output switch. The output switch supplies an electrical device, connected electrically in series with the full wave bridge rectifier and the output switch, with a constant average current of sufficient level to maintain the electrical device in a desired operating condition.

Abstract: An economical digital voltage sag compensator for overcoming sags in distributed electrical power. The voltage sag compensator employs an inexpensive micro-controller, a full wave bridge rectifier, a DC power supply, a voltage divider and an output switch. The micro-controller continuously monitors and evaluates, with respect to a setpoint measured in volt-seconds, the rectified DC voltage. At regularly spaced trigger events, as determined by the micro-controller, the micro-controller concurrently monitors the rectified DC voltage, evaluates the monitored voltage with respect to the setpoint, produces an output signal and sends that output signal to the output switch. The output switch supplies an electrical device, connected electrically in series with the full wave bridge rectifier and the output switch, with a constant average current of sufficient level to maintain the electrical device in a desired operating condition.

Abstract: The invention disclosed is useful in an I/O system of a programmable controller and provides a method and circuitry by which control and diagnostic information is exchanged between a control unit of an I/O module and a plurality of input/output points of the I/O module. A control signal is generated in the control unit in the form of sequential pulse frames such that the control information is defined by a series of pulse width modulated pulses. Each frame includes a no-pulse time period following the review of pulses to mark the end of a frame. Each I/O point receives a control signal of its own and generates a clock pulse in response to each pulse. The clock pulse initiates a sampling of the corresponding pulse and simultaneously initiates return of a diagnostic signal value to the central unit. Thus, the control signal provides for sampling of its own content and provides for a return of a diagnostic data bit for each control bit.

Abstract: A combined input/output circuit is provided which is configurable either as in input circuit or an output circuit for use in a programmable controller. The input/output circuit includes apparatus which detects undesired overcurrent and overvoltage external conditions and adaptively protects itself from such conditions. The circuit includes a sensing circuit which is capable of sensing overcurrent conditions and detecting input data depending on the configuration of the input/output circuit. The inherent characteristics of a switching device used to configure the circuit in either an input or output state are used to detect overcurrent and to limit fault current.

Abstract: A threshold detection circuit is provided for determining when a data input signal exhibits an amplitude which exceeds a first programmable threshold level, is less than a second programmable threshold level or between the first and second levels. Respective scaling circuits scale down the data input signal and a line voltage signal which is supplied to the circuit to generate a scaled data input signal and a scaled line voltage signal. The threshold detection circuit scales the first and second threshold levels by a predetermined factor. The scaled data input signal is compared with the scaled first and second threshold levels. In response to this comparison, the output of the circuit assumes a first logic state when the data input signal exceeds the first threshold level and assumes a second logic state when the data input signal exhibits an amplitude less than the first threshold level. The comparison is repeated for the second threshold level.

Abstract: The invention disclosed is useful in an I/O system of a programmable controller and provides a method and circuitry by which control and diagnostic information is exchanged between a control unit of an I/O module and a plurality of input/output points thereof. A control signal is generated in the control unit in the form of sequential pulse frames such that the control information is defined by a series of pulse width modulated pulses. Each frame includes a no-pulse time period following the review of pulses to mark the end of a frame. Each I/O point receives a control signal of its own and generates a clock pulse in response to each pulse. The clock pulse initiates a sampling of the corresponding pulse and simultaneously initiates return of a diagnostic signal value to the central unit. Thus, the control signal provides for sampling of its own content and provides for a return of a diagnostic data bit for each control bit.

Abstract: Input/output circuitry is disclosed for use in an I/O system of a programmable controller. The circuitry is protected against overcurrents without the use of fuses or circuit breakers, and is automatically restored to normal operation following correction of an overload condition. Diagnostic signals are produced for monitoring the operating condition of the circuitry. The invention includes an insulated gate transistor (IGT) having a main current section carrying a majority of the load current and an emulation section which carries a fractional portion of the load current. The emulation section current tracks the total current at all times. A current sensor monitors the emulation section current and provides a signal representing the instantaneous load current. This signal is continuously compared with preselected reference levels to derive a set of diagnostic signals that are indicative of the operating condition of the circuit, and whether output loads are open or shorted, for example.

Abstract: The invention disclosed provides circuitry which is selectively operable either as an input point or as an output point in a programmable controller having multiple input and output points for exchanging signals between a central processing unit (CPU) of the controller and a process being controlled. Preferably, operation as an input point or as an output point is under control of the CPU. The invention includes a common input/output terminal for terminating both input and output devices; an input return terminal for terminating a return conductor from the input device; an output return terminal for terminating a return conductor from the output device; a preload resistor connected between the input/output terminal and the output return terminal so that a status signal is developed across the preload resistor indicating the status (generally, open or closed) of the input device; and an insulated gate transistor (IGT) connected between the input/output terminal and the input return terminal.

Abstract: A two-stage electrical braking system for a variable speed alternating current induction motor powered from a variable frequency, variable voltage power source utilizes capacitance connected across a primary winding of the motor in a first stage of braking and short-circuits the primary winding in a second braking stage. The system is arranged such that the control of the two braking stages is independent of the motor terminal voltage and braking can be initiated by either a braking command or automatically upon interruption of power to the system. The control system uses a fixed time delay to initiate the second stage of braking a predetermined time interval after the first stage is initiated.

Abstract: A single phase AC to DC power converter is provided which accepts a single AC line input voltage and provides a DC output voltage. Input current feedback is used to control the converter and to provide high quality sinusoidal line currents in phase with the applied line voltage. In another embodiment, a three phase AC to DC converter is realized as a delta connection of three isolated single phase AC to DC converters. Reduction in peak transistor currents of the switching transistor in each single phase converter is accomplished by the introduction of third harmonics to each of the single phase AC to DC power converters. Each of the three single phase AC to DC converters are synchronized so that the current pulses at the outputs of the three AC to DC converters are staggered in time reducing the amount of filtering required at the load.