Abstract: The low-frequency, low power switching voltage switching pre-regulator is operable to propagate The pre-regulator is comprised of a chopping circuit, a pre-driver switching circuit and a feed back circuit. The output of the chopping circuit defines the output of the voltage pre-regulator and an input voltage is received at the input of the chopping circuit. The feedback circuit senses the magnitude of the voltage at the chopping circuit and derives a feedback signal in response thereto. The PWM interface circuit receives the feedback signals and a PWM signal of the type generally derived from a microprocessor. The PWM interface circuit switches the chopping circuit in response to the feedback and the PWM signals.

Abstract: The low-frequency, low power switching voltage switching pre-regulator is operable to propagate The pre-regulator is comprised of a chopping circuit, a pre-driver switching circuit and a feed back circuit. The output of the chopping circuit defines the output of the voltage pre-regulator and an input voltage is received at the input of the chopping circuit. The feedback circuit senses the magnitude of the voltage at the chopping circuit and derives a feedback signal in response thereto. The PWM interface circuit receives the feedback signals and a PWM signal of the type generally derived from a microprocessor. The PWM interface circuit switches the chopping circuit in response to the feedback and the PWM signals.

Abstract: A low side line driver (10) includes a slew rate limiter (12) providing current to a pre-charge reference circuit (16). The pre-charge reference circuit (16) generates a constant voltage at the input of a pre-drive circuit (18). Upon a transition to the active state, the pre-charge reference circuit (16) is disabled and current from the slew rate limiter (12) flows to pre-drive circuit (18) which becomes enabled without undue propagation delay or high instantaneous slew rate due to the pre-charge voltage generated by the pre-charge reference circuit (16) before turn on. The pre-drive circuit (18) provides base current to an output driver (22) from a negative voltage created in a charge pump (28). At turn off, an active turn off circuit (26) produces a short output pulse causing rapid discharge of base capacitance of the output driver (22) in order to minimize turn off propagation delay.

Abstract: A method and apparatus is used in a motor vehicle to serially communicate data between two or more communication nodes coupled to a data bus. Each communication node receives and transmits information on the data bus. Signals representative of operation of the vehicle are received directly by nodes and encoded for transmission to one or more other nodes via the data bus. The signals, which may for example originally be in parallel format, are encoded into serial digital data for data bus transmission. Each bit of the serial digital data is formatted into subbits of unequal duration. A designated module then receives and decodes the serial digital data for information or control purposes. Preferably the subbits progressively increase in duration with one working embodiment having three subbits of seven (7), eight (8) and nine (9) microseconds, respectively, to define a bit time of twenty four (24) microseconds.

Abstract: A vortex valve includes a housing having a cylindrical side wall and opposite ends to define a vortex chamber. The sidewall of the housing has a primary tangential inlet through which liquid may enter the vortex chamber in a manner to promote swirl within the vortex chamber and an outlet at one axial end of the vortex chamber. The outlet represents at least 50% of the area of the end of the vortex chamber in which it is situated and in the vortex chamber has a length which is at least one and a half times the diameter of the outlet. The vortex valve requires only a low head to initiate vortex flow.

Abstract: A bus driver circuit for a multiplex communications system is configured from a limited number of components to withstand short circuiting of a connected bus circuit to voltage levels from ground potential to double conventional voltage levels encountered within a motor vehicle, i.e. twenty four (24) volts. The bus driver circuit does not interfere with bus operation if local power or ground is lost by one or more system node including the circuit, and can operate at relatively high frequencies, for example of approximately 83.3 to 166.7 kilobits per second (KBPS). Each line of a two-line bus is driven by a transistor whose current flow is limited by emitter degeneration and, in the case of the transistor which sinks current from the bus, a separate current control transistor which monitors current flow through its associated bus driver transistor and reduces its base drive at high temperatures to limit current flow therethrough and compensate the circuit for temperature variations.

Abstract: A method for specifying characteristics of an integrated circuit wherein complementary output signals of the integrated circuit are required to cross or equal one another within a signal transition box during transitions of the complementary output signals. The signal transition box is defined by a maximum output signal level as a high side, a minimum output signal level as a low side, a minimum delay time as a leading side and a maximum delay time as a trailing side. A maximum allowable slew rate preferably is also defined.

Abstract: A switching module having a plurality of switching channels responsive to a microcontroller for coupling electrical power to a load, and decoupling electrical power in the event an undesired operating condition is sensed. Each switching channel includes a switching transistor and transistor driver. Monitoring circuitry senses the actual voltage drop across the load to provide the controller with an indication of undesired operation. A limiting resistor limits the transistor drive such that the transistor is forced out of satuaration during a high power condition, thereby avoiding undesired power dissipation which would otherwise occur if operation in the saturated condition continued.

Abstract: A tool for assembling press-in tube connections which comprises pivoted plier elements having an L-shaped nose with two pairs of opposed recesses at right angles to each other to grip tubes in the plane of the pliers, or perpendicular to the plane, with in-turned ends on the handle to limit the closure to prevent crushing of the tube while providing both a palm rest for application of pressure. The gripping jaws are made with cutters below the jaws and are also designed to facilitate the application of pressure to releasable couplings to assist in the removal of tube.