A method of and apparatus for producing a 3-D model by forming a continuous plurality of parallel layers of modeling material comprising a) producing a plurality of bead producing drops of the modeling material for deposition at desired locations b) controlling the locations and timing of deposition to produce vectors, in any and all directions required to produce an outer surface defining wall of said layer with a desired surface finish; c) adjusting the distance of the location of drop production to the location of drop deposition in preparation for the formation of a subsequent said layer; and d) repeating steps a), b), and c) as required to complete the model.

3-d model making

The 3-D Model Maker (1) of the present invention is a device that builds three dimensional models of computer generated (e.g. CAD) structures by vector plotting layer-upon-layer applications of solidifiable substances. The layers are formed by expelling minuscule beads of the substances in liquid or flowable phase onto a platform (10) from one or more jets (60), the jets and platform being relatively movable in X, Y and Z coordinate system. The beads are deposited along vectors, during X/Y relative movement, on the platform (10), one at a time, layer-upon-layer, to build the model. The jets (60) and platform (10) are moved relatively to one another in accordance with instructions from the computer (controller) (11) to form each layer in the X-Y plane (in a manner analogous to an X-Y vector plotter) and either the platform (10) or the jets (60) may move in the Z direction to allow the jets to form subsquent layers.

3-D model maker

An automatic charging apparatus comprises a rectifier circuit composed of a plurality of diodes and thyristors, said diodes and thyristors being arranged in a bridge connection, a phase control circuit for obtaining the charging voltage of a battery by controlling the phase of said thyristors, a voltage setting resistor for setting a charging voltage suitable for the state of said battery, a current setting resistor for setting a charging current suitable for the state of said battery and a current control circuit which obtains the charging current best suited to the state of the battery by controlling the pulse width of base current flowing in a transistor connected to the outputs of said thyristors. As a result, it is possible to efficiently charge the battery with charging voltage and current best suited to the state of the battery even if the battery is of large capacity.

Automatic charging apparatus

A battery charger control system and method for maximizing output power to a battery This is achieved by ensuring operation at either the maximum allowable input current or the thermal limit imposed by the battery charger using an on-line controller In the invention, the thermal limit is determined by the junction temperatures of the two main IGBT's Because direct measurement of these temperatures is impractical, they must be calculated by a computer algorithm that uses various on-line measurements Test results for a 8 kW battery charger indicate reduction in the bulk charging time from conventional battery chargers of about 26% when charging a set of NiFe batteries

Battery charger control system

The present invention is directed to a battery charger for charging a battery pack. The battery charger includes a plurality of components including a power supply. The battery charger also includes a temperature sensor that senses the temperature of at least one of the plurality of battery charger components, for example a transformer. The battery charger power supply is adjusted based on the temperature of the at least one of the plurality of battery charger components.

Battery charger and method of charging a battery

A battery charging system incorporating a unijunction relaxation oscillator circuit and an electronic current limiting control circuit for de-energizing the relaxation oscillator circuit when the battery charging current exceeds a certain minimum value. The system preferably also includes a voltage control circuit and a temperature control circuit all of which are connected in parallel with the electronic current limiting control circuit in order to de-energize the relaxation oscillator circuit when the respective voltage and temperature of the system exceeds certain predetermined minimum values. The electronic current limiting control circuit, the voltage control circuit and the temperature control circuit are included in corresponding solid state integrated circuits.

D. Bruce Randolph

Papers

Controlled battery charging system