Abstract: A circuit and method produce a pump current (I.sub.p) at the output (31) of a charge pump (26). A switching transistor (32, 35) is coupled at a node (38, 39) to a current source transistor (33, 34) to produce the pump current at a specified magnitude in response to an input pulse (V.sub.PU, V.sub.PD). A charge is stored on a parasitic capacitance of the node. A charge conduction path (42, 43) is coupled to the node and enabled on one transition edge of the input pulse to alter the charge by routing to a discharge node (45) to reduce charge flowing to the output as an error current. The charge conduction path is disabled on the other transition edge of the input pulse to isolate the node from the output.

Abstract: A DC-to-DC converter includes a pulse width modulation circuit for modulating a switch to produce current pulses having at least a minimum pulse width to thereby control an output voltage to the load. The converter also includes a current limit determining circuit for determining when a desired peak current is no longer sufficient to maintain a desired output voltage thereby defining a current limit condition. In addition, the pulse width modulating circuit, when operating at the minimum pulse width, thereby defines a minimum pulse width condition. Accordingly, the converter preferably further includes an over-current determining circuit for determining an over-current condition responsive to the minimum pulse width condition being reached during a current limit condition. The converter may turn off the switch responsive to an over-current condition. A blanking signal may be used to clamp a comparator and established a minimum pulse width.

Abstract: A DC-to-DC converter suitable for use in light-powered electronic systems. The DC electrical output from a solar cell is stepped-up in a chopper-type inverter that is driven by a gated oscillator. The output from the inverter is then rectified and is adapted to be applied to a load through a series connected switch whose on/off state is determined by the output from a voltage regulator. Connected between the rectifier and the series switch are energy storage capacitors which become charged when the series switch is open and which provide energy to the load when the series switch is closed. Feedback from the regulator circuitry controls the on/off state of the gated oscillator and, therefore, the energy delivered by the inverter. Further circuitry is provided for signaling a light transmitting device that the fiber-optic link delivering energy to the photo cell is intact.

Abstract: An electric adjuster is so designed that, in order that an a.c. power supply or an a.c. signal as an input is arbitrarily adjusted or converted with high efficiency and outputted, the ratio of winding of a transformer can be arbitrarily adjusted or continuously adjusted. Thus the output voltage is automatically adjusted to become constant.

Abstract: A nozzle plate contains nozzles, liquid chambers and connection channels between liquid chambers and supply containers for the liquid. All the function regions are produced integrally as a microstructure body by casting from one or more microstructured mold inserts. The smallest implementable spacing of the nozzles from one another can be considerably smaller than in the previously known plates, which allows increased printing density.

Abstract: An internal AC adapter which incorporates a space efficient EMI filter is positioned within a main chassis portion of a portable personal computer having at least one energy-demanding component also positioned within the main chassis portion. The internal AC adapter, which converts alternating current received from an alternating current main to direct current for transmission to the energy-demanding components, includes a first connector for electrically connecting the internal AC adapter to the alternating current main, a bridge rectifier circuit having an AC input side electrically connected to the first connector and a DC output side and a space efficient electromagnetic interference filter having an input side electrically connected to the DC output side of the bridge rectifier circuit and an output side. The bridge rectifier circuit converts alternating current received from the first connector to direct current for transmission to the electromagnetic interference filter.

Abstract: A reference voltage generating circuit outputs a reference voltage (used for comparison of magnitude with an analog voltage) at a plurality of levels by using a differential amplifier to amplify voltages at nodes formed by mutually adjacent resisters among a plurality of resistors comprising a ladder resistor unit which is optionally selected by a decoder and an analog switch unit.

Abstract: A voltage transformer with storage reactor (15) and with at least one circuit breaker (14, 14a, 22, 22a), in which the current flowing in the storage reactor (15) establishes the turning off and turning on of the circuit breaker (14, 14a, 22, 22a). A comparator (33) compares the current flowing in the storage reactor (15) to a stipulated threshold value. The circuit breaker (14, 14a, 22, 22a) is when the threshold value is traversed. A timer (17, 17a, 17b), after a voltage jump occurs on storage reactor (15), keeps the circuit breaker (14, 14a, 22, 22a) in the existing switching state for the time fixed by the timer (17, 17a, 17b). The voltage transformer according to the invention can be built with a few discrete components in an extremely cost-favorable manner. One preferred application is given in a motor vehicle.

Abstract: Single faults in shift registers incorporated on monolithic printing heads can render inoperable large numbers of printing actuators, as data will either be stuck high or stuck low for subsequent shift register and actuator stages. This can reduce the effectiveness of other means of fault tolerance, and increase the device sensitivity to faults in individual, normally redundant, actuators. A printing head is disclosed which provides block fault tolerance in the shift registers, limiting the effect of shift register fabrication faults to small numbers of redundant actuators. This allows a high probability of defect correction by other forms of fault tolerance integrated on the chip, thereby increasing overall device yield.

Abstract: A power supply for use in a printer provides a current progressively small with increasing transfer roller impedance. A reference current section RC sets a voltage Vr indicative of a reference current Ia of an output current Iout of the power supply PS. A voltage generator VG provides an output voltage Vout of the power supply PS. A voltage monitor VM monitors the output voltage to provide a voltage-monitoring signal Vm to an operational section E. The operational section E determines a correction value of the output current Iout on the basis of the voltage Vr and the voltage-monitoring signal Vm. The correction value is progressively small as the voltage-monitoring signal Vm increases.

Abstract: A rail-to-rail voltage-to-current converter converts a variable differential voltage signal having first and second voltage signal components, to an output current signal. The converter includes a first voltage-to-current converter configured to receive a voltage signal component and a reference voltage signal to provide a substantially linear output current signal. A second voltage-to-current converter receives the other one of the voltage signal components and the reference voltage signal to provide a second substantially linear output current signal. An adder combines the first and second output current signals to provide a substantially linear voltage/current characteristic over a wide range of available voltage signals generated by a power supply.

Abstract: A high power factor electronic ballast for operating a high pressure gas discharge lamp comprises a boost converter function and a buck function. The boost converter function and the buck function have common components. The combination boost-buck converter reduces parts count, as compared to the parts count required for the separate boost and buck circuits of the prior art, by making some components of the single circuit act simultaneously in both the boost and buck functions. The rigid forcing of the ac input current waveform to follow the ac input voltage waveform is relaxed, to give performance priority to the buck function for the common components. Harmonics are allowed to enter the system in moderation in return for a less expensive and more reliable system that does not compromise lamp power control.

Abstract: A quickly restartable power supply apparatus which can quickly restart with a power-saving integrated circuit in power-saving mode by utilizing the reference output signal of the power control circuit as a restarting control signal thereby rapidly restarting the power supply apparatus in power-saving mode with lower circuitry complexity and cost and good reliability. Further, the quickly restartable power supply apparatus can also decrease the power dissipated by the starting resistor by using the reference voltage signal to control the switch control circuit and the second switching means such that after the power supply control circuit is activated, the current in the starting resistor is cut off and no power is dissipated by the starting resistor.

Abstract: A multi-deck power converter module assembly for connection with a substrate (e.g., a host board) having connection regions disposed on its surface includes a second circuit board positioned over a first circuit board, the second circuit board having apertures extending from an upper surface to a lower surface of the second circuit board. At least two rail members are positioned over the second circuit board, each rail member having a first and a second plurality of holes. A pair of spacers are disposed between the first and second circuit boards, each spacer extending through one of the apertures of the second circuit board and received within one of the first plurality of holes of one of the rail members. Terminal pins are attached to the first circuit board, at least one terminal pin extending through the second circuit board and a corresponding one of the second plurality of holes for connection to one of the connection regions on the substrate.

Abstract: A line powered supply for a wall mounted lighting load control system includes a power MOSFET in series with a load control relay and a second MOSFET in parallel with the load control relay. When the lighting load is off, the MOSFET in parallel with the load relay is selectively opened to charge a capacitor feeding a regulator used to provide control system power. When the lights are on, the capacitor provides control system power. The MOSFET in series with the load control relay is open circuited to provide AC to recharge the capacitor whenever the regulator drop out voltage is reached. The MOSFET conducts for all but a very small portion of the AC cycle so that substantially all the AC power is applied to the lighting load. A second AC to DC power converter uses similar MOSFET switching to use partial AC voltage cycles to charge a capacitor and provide low voltage DC power from higher AC voltages.

Abstract: A power supply control circuit for conditioning an electronic circuit's input voltage at ground or at the operation voltage of an external power supply so as to permit the electronic circuit to receive a supply voltage at ground potential until the power supply transitions above a threshold voltage level and thereafter to provide operation level voltage of the power supply to the electronic circuit. The circuit comprises a transconducting means having its high current node coupled to an external power supply, its controlling node coupled to a voltage reference means. The transconducting means has its controlled high current node coupled through a power input node to the power input for the electronic circuit to condition the voltage received thereby. The power input node is in turn coupled through a pull down means to ground potential.

Abstract: An electronic printing device is disclosed which uses flexible whiskers to transfer a charge corresponding to an image to a dielectric recording surface. The recording surface preferably has areas of differing conductivity so that microfields form on the dielectric surface. Ink, preferably non-charged, may then be attracted to the recording surface through dipole forces and later transferred to paper.

Abstract: The present invention provides a method and apparatus that selectively connects a voltage source to a plurality of groups of resistive printing elements, arranged substantially in a single row, in a thermal print head. The power available at printing elements selected to print is greater than that available at printing elements not selected to print.

Abstract: A voltage control temperature compensated circuit for coupling to a supply that provides a supply voltage at first (102) and second supply nodes (103) and the voltage control circuit for generating and regulating an output voltage (VREG). The voltage control circuit includes an output device (18) coupled to the first and second supply nodes for generating the output voltage and a base coupled bipolar pair controller (15 and 14) coupled to the first and second supply nodes for generating an internal high-side (106) voltage reference (104) and for regulating the output voltage to compensate for changes from the desired response between the output voltage and the internal reference voltage.

Abstract: A method for cleaning nozzles in an ink jet printer includes the steps of: ejecting ink from a first plurality of the nozzles that are not frequently used in printing every first period; and ejecting ink from a second plurality of the nozzles which are frequently used in printing every second period, wherein the first period is different from the second period.