Abstract: A method and system for controlling a fluid valve are described that avoid the effects of hysteresis. In hysteresis, the power signals associated with a valve position are different on the upstroke and downstroke. As a result, predicting the valve position can be difficult if you only know the current power signal. Instead of using upstrokes and downstrokes, a valve can momentarily be set to zero power, or a rest position when receiving a new command signal. This way the command signal is applied from a zero power or rest position, making the valve position more predictable and accurate.

Abstract: A circuit includes a reconfigurable rectifier, a voltage balancer, and a pair of converters. The reconfigurable rectifier includes an ac input port and three output ports. In a first configuration, the reconfigurable rectifier can deliver power at a first output port and, in a second configuration, to at least a second output port. The voltage balancer includes first and second ports coupled to second and third output ports of the reconfigurable rectifier and is configured to balance received voltage at the first and second ports. The first converter has an input coupled to the first port of the voltage balancer and an output at which a first converted voltage signal is provided. The second converter has an input coupled to the second port of the voltage balancer and an output at which a second converted voltage signal is provided.

Abstract: A power converter circuit rectifies a line voltage and applies the rectified voltage to a stack of capacitors. Voltages on the capacitors are coupled to a plurality of regulating converters to be converted to regulated output signals. The regulated output signals are combined and converted to a desired DC output voltage of the power converter. Input currents of the regulating converters are modulated in a manner that enhances the power factor of the power converter.

Abstract: A circuit includes a reconfigurable rectifier, a voltage balancer, and a pair of converters. The reconfigurable rectifier includes an ac input port and three output ports. In a first configuration, the reconfigurable rectifier can deliver power at a first output port and, in a second configuration, to at least a second output port. The voltage balancer includes first and second ports coupled to second and third output ports of the reconfigurable rectifier and is configured to balance received voltage at the first and second ports. The first converter has an input coupled to the first port of the voltage balancer and an output at which a first converted voltage signal is provided. The second converter has an input coupled to the second port of the voltage balancer and an output at which a second converted voltage signal is provided.

Abstract: A power converter circuit rectifies a line voltage and applies the rectified voltage to a stack of capacitors. Voltages on the capacitors are coupled to a plurality of regulating converters to be converted to regulated output signals. The regulated output signals are combined and converted to a desired DC output voltage of the power converter. Input currents of the regulating converters are modulated in a manner that enhances the power factor of the power converter.

Abstract: A shifting mechanism for a bicycle or other wheeled cycle has at least two gear wheels, of which at least one is segmented. The segments are movable into and out of a driving position. Motion of the segments occurs at a circumferential location out of the driving zone, at a location where the driving band, typically a chain, is not contacting the segment. The shifting mechanism can be provided at the front chain ring, or at the rear, gear sprocket. For a front chain wheel, the free zone is generally the rearward half of the chain ring, while for the rear gear sprocket, the free zone is generally the forward half. The moving segments can be toothed gates which flip perpendicularly to the plane in which the chain resides. The gates may be actuated by a moving mechanism powered by an actuator, such as a D.C. motor, under control of a signal processor, such as a microprocessor.

Abstract: A shifting mechanism for a bicycle or other wheeled cycle has at least two gear wheels, of which at least one is segmented. The segments are movable into and out of a driving position. Motion of the segments occurs at a circumferential location out of the driving zone, at a location where the driving band, typically a chain, is not contacting the segment. The shifting mechanism can be provided at the front chain ring, or at the rear, gear sprocket. For a front chain wheel, the free zone is generally the rearward half of the chain ring, while for the rear gear sprocket, the free zone is generally the forward half. The moving segments can be toothed gates which flip perpendicularly to the plane in which the chain resides. The gates may be actuated by a moving mechanism powered by an actuator, such as a D.C. motor, under control of a signal processor, such as a microprocessor.

Abstract: A centrifuge rotor cover assembly for use with a centrifuge having a rotor and a housing enclosing the rotor and including a lid movable between a closed position overlying the rotor and an open position providing access to the rotor. The cover assembly includes a rotor cover removably coupled to the lid. Means are provided for engaging the rotor cover with the rotor for rotation therewith and for uncoupling the cover from the lid in response to the lid being moved to the closed position. Means are also provided for disengaging the rotor cover from the rotor and for coupling the cover to the lid in response to the lid being moved to the open position.

Abstract: A vending machine control circuit having a plurality of capacitively coupled switches for enabling a customer to indicate his choice of a product to be vended. A logic circuit is responsive thereto for controlling the vending of products by the generation of vend signals directed to a plurality of vend solenoids. Out-of-product switches are wired in series with the vend solenoids such that if a solenoid is activated, but no current flows therethrough, a current sensing circuit is utilized to detect that the product is out-of-stock. This is a significant improvement over prior art control circuits, particularly from the standpoint of decreased wiring requirements in the vending machine.The control circuit has an early power failure detecting circuit which allows critical tasks within the machine to be finished prior to removal of the power. This feature allows the machine to shut down in an orderly manner, and enables the totalizer to maintain track of sales even in the event of a power failure.

Abstract: A vending machine control circuit having a plurality of capacitively coupled switches for enabling a customer to indicate his choice of a product to be vended. A logic circuit is responsive thereto for controlling the vending of products by the generation of vend signals directed to a plurality of vend solenoids. Out-of-product switches are wired in series with the vend solenoids such that if a solenoid is activated, but no current flows therethrough, a current sensing circuit is utilized to detect that the product is out-of-stock. This is a significant improvement over prior art control circuits, particularly from the standpoint of decreased wiring requirements in the vending machine.The control circuit has an early power failure detecting circuit which allows critical tasks within the machine to be finished prior to removal of the power. This feature allows the machine to shut down in an orderly manner, and enables the totalizer to maintain track of sales even in the event of a power failure.

Abstract: A vending machine control circuit having a plurality of capacitively coupled switches for enabling a customer to indicate his choice of a product to be vended. A logic circuit is responsive thereto for controlling the vending of products by the generation of vend signals directed to a plurality of vend solenoids. Out-of-product switches are wired in series with the vend solenoids such that if a solenoid is activated, but no current flows therethrough, a current sensing circuit is utilized to detect that the product is out-of-stock. This is a significant improvement over prior art control circuits, particularly from the standpoint of decreased wiring requirements in the vending machine. The control circuit has an early power failure detecting circuit which allows critical tasks within the machine to be finished prior to removal of the power. This feature allows the machine to shut down in an orderly manner, and enables the totalizer to maintain track of sales even in the event of a power failure.

Abstract: A power angle relay to measure the power angle of a synchronous alternator. The power angle relay receives a reference voltage signal corresponding to a fixed point on a reference voltage waveform (usually a zero crossing) from some point in the power system to which the alternator is normally synchronized and an electric signal representative of the angular position of the shaft of the synchronous alternator and is operable to combine the two to provide an indication representative of the power angle between the direct axis of the synchronous alternator and said fixed point.

Abstract: A totalizer system having a first electronic device coupled to the vending machine for storing the number of vends (data) made by the vending machine, and a second device for interrogating the first device and providing a readout of said vends, e.g., in code, actual money value, or actual number of vends, or any form desired. The present system preferably includes an optical interrogation scheme using modulated light for transmitting stored vends in the first device to the second device thus eliminating human error, and an electronic memory in the first device that will store vends for a prolonged period of time even if the vending machine is unplugged.

Abstract: A totalizer for recording the income of a multiprice vending machine, the totalizer including a device to determine the value of the item selected, the fact that a sale was made, and a counter to total the value of all items selected. The totalizer preferably verifies the correctness of the value of the item selected to prevent erroneous counts and also preferably generates a coded output signal representing the price line of the vending machine providing information.