Abstract: An apparatus for and method of control of a switch (102) in an electrical power converter (100) using pulse width modulation to regulate output voltage (112) and current. The method allows precise output voltage regulation to be achieved whilst accurately controlling the proportion of load-current supplied by multiple modules connected in parallel. A ramped waveform (408), consisting of a component representing the instantaneous current and a component representing the input voltage applied since the switch (102) switched on in the current PWM cycle, is compared with an error signal (406) to determine the width of each PWM pulse.

Abstract: A mask (110; see also 160, 210, 260, 310, 408, 500, 702, 802, 904) having a plurality of openings (cells) is disposed on, or nearly on, the surface of a substrate (102), the openings (112) of the mask being aligned over a corresponding plurality of pads (104) on the substrate. The openings in the mask are filled with solder material (114). A pressure plate (120) is disposed over the mask to capture the solder material in the cells. Heat is directed at the mask (through the pressure plate) to reflow the solder. This is done in an inverted or partially inverted orientation. The stackup (assembly) of substrate/mask/pressure plate may be un-inverted prior to cooling. Mask configurations, methods of mounting the masks, and solder material compositions are described. The methods are robust, and are well suited to fine pitch as well as coarse pitch ball bumping of substrates.

Abstract: Methods of providing and breeding trees having more easily extractable lignin due to the presence of a cinnamyl alcohol dehydrogenase (Cad) null gene are presented.

Abstract: A method and apparatus for measuring a physical quantity, property or condition and for transmitting a code representing the measured physical quantity, property or condition. The method includes the steps of developing a first signal in response to a physical quantity, property or condition, sampling the first signal to produce an instantaneous first signal value, assigning a first code to the instantaneous first signal value, and transmitting the first code for reception by a receiver. The method and apparatus are explained in connection with a vehicle tire monitoring apparatus wherein plurality of tire units measure tire pressures and temperatures and transmit values representing pressure and temperature to a central receiver located in a cab portion of the vehicle.

Abstract: A method and apparatus for measuring a physical quantity, property or condition and for transmitting a code representing the measured physical quantity, property or condition. The method includes the steps of developing a first signal in response to a physical quantity, property or condition, sampling the first signal to produce an instantaneous first signal value, assigning a first code to the instantaneous first signal value, and transmitting the first code for reception by a receiver. The method and apparatus are explained in connection with a vehicle tire monitoring apparatus wherein plurality of tire units measure tire pressures and temperatures and transmit values representing pressure and temperature to a central receiver located in a cab portion of the vehicle.

Abstract: A method of attaching a semiconductor chip to a mounting surface is disclosed. A solder barrier is applied to the mounting surface, and a preform of solder is located within the solder barrier. The preform is heated and then cooled in a vacuum to preflow the solder and secure the solder to the mounting surface substantially without voids. The semiconductor chip is then placed over the preflowed solder, which is reheated and then recooled in a vacuum to secure the chip to the mounting surface.

Abstract: In one aspect, the present invention consists in a heat absorber for a solar heating system, said absorber including a support member, a flexible heating bag having inlet and outlet connections and arranged to be supported in use by said support member, and a retaining member positioned in use on the opposite side of said bag from said support member so as to control the depth of said heating bag therebetween when said heating bag is filled with fluid, said retaining member being adapted to allow at least a substantial portion of the face of said heating bag adjacent thereto to be exposed to sunlight in use.

Abstract: A method of growing monocrystalline bismuth rare earth iron garnet, either as a single crystal or as an epitaxial layer, from a solution containing composing components of the garnet together with a flux. The flux consists essentially of a mixture of Bi.sub.2 O.sub.3 and RO.sub.2, wherein R is at least one of the elements Si, Ge, Ti, Sn, Zr, Ce and Te, wherein the system Bi.sub.2 O.sub.3 --RO.sub.2 includes a eutectic composition having a eutectic temperature which is below the melting temperature of pure Bi.sub.2 O.sub.3. By using these Bi.sub.2 O.sub.3 --RO.sub.2 fluxes, the monocrystalline garnets produced have lower optical absorption coefficients at, for example 5100 A and 5600 A than similar garnets grown using lead-containing fluxes. Furthermore higher growth rates and higher growth temperatures are possible when using the Bi.sub.2 O.sub.3 --RO.sub.2 fluxes rather than lead-containing fluxes.

Abstract: An improved ignition distributor breaker contact point set is provided which includes an electrically conductive plate member including a first breaker contact in electrical contact with the plate member; an electrically conductive, pivotably mounted breaker arm having at one end thereof a second breaker contact, the breaker arm being spring loaded by affixation to an electrically conductive leaf spring; and a condensor having a first electrically conductive terminal in electrical contact with said plate member and a second electrically conductive terminal which is insulated from said plate member. An electrically conductive, elongated support strap is provided, said support member spanning directly between and physically and electrically connecting the second electrically conducting terminal of the condensor and the leaf spring art.