Abstract: An adapter for electrical power that includes a rectifier coupled to a transformer with a primary coil and a secondary coil. The secondary coil includes a first end tap, a second end tap, and a center tap. A first switch is coupled between the first end tap and a primary side ground. A second switch is coupled between the second end tap and the primary side ground. A controller is coupled to the first switch and to the second switch so that during one or more intervals, the first switch and the second switch are alternately open and closed a predetermined number of times, wherein the initial switch closed each interval alternates between the first switch and the second switch, and after the predetermined number of times, both the first switch and the second switch are opened for a predetermined time period.

Abstract: Embodiments of an adapter are disclosed that include a transformer with a primary coil coupled to an H-bridge. The H-bridge is controlled by a control circuit that controls a voltage across the primary coil using the H-bridge, and the control circuit is configured to control the H-bridge so that during each of one or more intervals, a first voltage pulse is applied across the primary coil in a start direction, wherein the start direction alternates between a first direction and a second direction each interval. Then, a direction of subsequent voltage pulses across the primary coil is alternated between the first direction and the second direction a predetermined number of times. After the predetermined number of times, a last voltage pulse is applied across the primary coil; then, voltage across the primary coil is reduced to zero for a predetermined time.

Abstract: Embodiments of a power supply are disclosed that include a first voltage converter having a first feedback controller and a first regulated output, and second voltage converter having a second feedback controller and a second regulated output electrically coupled to the first regulated output. The power limit of the first voltage converter is lower than the power limit of the second voltage converter, and a reference voltage for the first feedback controller is higher than the reference voltage for the second feedback controller.

Abstract: One embodiment of a display backlight driver integrated circuit can be configured for operation in at least two different ways. A first method transfers data from an EEPROM to hardware registers prior to regular operation. A second method also transfers data from an EEPROM to registers. However, hardware registers can be overwritten with data accepted from a control bus, prior to regular operation. A keyboard driver IC can detect the presence or absence of a cable to an LED. If the cable is absent, the driver IC will not supply power for the LED. One embodiment of a keyboard and display backlight control system can be configured to allow substantially independent operation.

Abstract: One embodiment of a display backlight driver integrated circuit can be configured for operation in at least two different ways. A first method transfers data from an EEPROM to hardware registers prior to regular operation. A second method also transfers data from an EEPROM to registers. However, hardware registers can be overwritten with data accepted from a control bus, prior to regular operation. A keyboard driver IC can detect the presence or absence of a cable to an LED. If the cable is absent, the driver IC will not supply power for the LED. One embodiment of a keyboard and display backlight control system can be configured to allow substantially independent operation.

Abstract: Methods and apparatus, including computer program products, implementing and using techniques for providing a computer peripheral including one or more keys. Each key has several light emitting diodes disposed on a face of the key. Each of the light emitting diodes can switch on or off in response to a data signal received from an application specific integrated circuit dedicated to the key. A corresponding key and manufacturing method, as well as a computer system including one or more such keys are also described.

Abstract: A method is disclosed for fabricating a low cost, elevated-temperature resistant part with a serrated surface and elevated-temperature structural properties similar to (within fifty percent (50%)) a superalloy material comprising the steps of: forming a master tool having the desired serrated surface; electro-forming the elevated-temperature resistant part by depositing three alloying elements comprising nickel, cobalt and manganese onto the master tool in the amounts of about 60%-70% nickel, 40%-30% cobalt and 0.05%-0.10% manganese; and separating the elevated-temperature resistant part from master tool.

Abstract: An electro-pneumatic brake control system for a railroad car including application and release solenoid valves having a fail-safe configuration in which full emergency brake pressure is delivered in the event of a power loss due to a train break-in-two for example. The present invention discloses a pressure limiting valve for the purpose of limiting the maximum pressure capable of being delivered in accordance with the existing car load weight sensed by an electric load sensor at the time a bower loss is experienced.

Abstract: An electro-pneumatic brake control system for a railroad car including application and release solenoid valves having a fail-safe configuration in which full emergency brake pressure is delivered in the event of a power loss due to a train break-in-two for example. The present invention discloses a pressure limiting valve for the purpose of limiting the maximum pressure capable of being delivered in accordance with the existing car load weight sensed by an electric load sensor at the time a power loss is experienced.

Abstract: A test connector for connecting an air brake test device to access ports of an air brake control valve device where such access ports are normally closed by check valves. A plurality of actuator devices corresponding in number to the access ports are provided in the test connector to unseat the check valves and conduct test air to the test device via central passages in the actuators. The actuators are piston operated in response to a pilot pressure received from a source of compressed air remote from the connector.

Abstract: A hydraulic brake actuator including a hydraulic parking brake that can be applied by mechanically locking up either a normal service brake application or a hand pump operated brake application. The lock-up mechanism includes a friction collar that surrounds the piston push rod and a hand pump actuated locking member that surrounds the friction collar. The friction collar and locking member have complementary conical surfaces that are engageable when hydraulic hand pump pressure is applied to a piston face of the locking member to wedge the friction member into pressure engagement with the piston push rod, as a means of locking up the push rod to obtain a parking brake. The locking member also includes a plurality of spring-like fingers that project axially from the periphery of the locking member and are provided with latching tabs adapted to enter a recess in the body to prevent return-movement of the locking member when the hydraulic hand pump operation is terminated.

Abstract: A combined hydropneumatic brake cylinder/air reservoir device having a hydraulic piston formed on the end of a push rod through which interconnected, different sized, pneumatic pistons operate to transmit the desired brake force. The hydraulic piston operates in a hydraulic cylinder having a slack adjuster piston arranged to supply or reduce the hydraulic fluid in the braking circuit in order to compensate for overtravel and undertravel of the pneumatic piston assembly due to brake shoe wear and brake shoe replacement respectively. The double-acting slack adjuster action results in the stroke of the pneumatic piston assembly being maintained constant to assure continued optimum operating efficiency.

Abstract: A hydro-pneumatic brake actuator arranged with a slack adjuster piston and one-way check valve device in the hydraulic path between a hydro-pneumatic actuator and a power piston, to which a friction brake element is connected for engagement with a vehicle wheel tread or brake disc during a brake application. During a brake release, the one-way check valve closes a passage through the slack adjuster piston to cause the piston to shift from its one extreme position to the other extreme position with the fluid flow, as the hydro-pneumatic actuator is moved from its application position to its release position. This in turn draws hydraulic fluid from the power piston chamber into a clearance volume created by shifting of the slack adjuster piston, and accordingly forces the power piston to retract a predetermined distance corresponding to the capacity of the clearance volume and the effective area of the power piston, thereby maintaining a constant brake shoe clearance during brake release.