A improved burner for metallurgical furnaces capable of utilizing gaseous or liquid fuels and air, enriched air or oxygen as an oxidant and adapted to accommodate rich fuel/oxidant mixtures is disclosed. The burner is capable of producing high temperatures and a reducing and non-decarburizing atmosphere without causing carbonization or other fouling of the burner or related furnace and without damaging the burner.

A process and apparatus for the production of intermediate hot metal suitable for further refining into steel is disclosed. The basic process includes the steps of heating a charge of ore in a reducing furnace having a reducing atmosphere therein comprising a mixture of reconditioned and recycled top gas from the reducing furnace and off-gas rich in hydrogen and carbon monoxide produced by a cupola melting unit to reduce the ore to iron, partially carburizing the reduced iron in the reducing fur...

Structure is disclosed for a charge-coupled device for generating reference signals indicative of black and white optical conditions and for generating an end-of-scan indicator signal. The black reference signal is generated by electrically and optically isolating one or more photosites of the CCD. A white reference signal is generated by injecting a controlled amount of charge into one or more elements of a shift register of a charge-coupled device. The end-of-scan indicator signal is generated...

There is disclosed a sample preparation chamber for a system for preparing samples of various compositions for assay by liquid chromatography. The sample preparation chamber is a container having a threaded cap and a threaded, lightweight, translucent plastic cup. A stirred/grinder shaft driven by a motor and connected to a propeller/grinder passes through the cap. The cap has a sloped bottom with a sump region, and a fill/empty pipe passes through the cap and has its outlet at or near the sump....

There is disclosed a diode snubber for the voltage transients generated in the parasitic inductance of a switched resistor when current therethrough is interrupted. Also disclosed is the use of such a diode snubber in: a series switched resistor regulator; a shunt switched resistor regulator; a hybrid switched resistor regulator and a passbank switched resistor regulator. Also disclosed is the use of a linear dissipative regulator in all these forms of switched resistor regulators to maximize th...

A new differential amplifier circuit including two current mode logic circuits, each comprising a pair of transistors whose emitters are connected to a common current source. The differential amplifier circuit receives three input signals, with a transistor in both of the current mode logic circuits being controlled by one of the input signals. The collector outputs of the two transistors controlled by a single input signal are connected together, and the collector outputs of the two transistors...

There is disclosed herein a system for providing control of multiple functions needed to perform eye surgery. A microprocessor based system controls a vacuum generation system using venturis and linear valves and a pneumatic system for driving vitrectomy probes and pneumatic scissors in either a variable frequency, multicut mode or a proportional cut mode where the cutting pressure is proportional to the position of a foot operated position sensor. The frequency of the vitrectomy probe cutting a...

There is disclosed herein a pump check valve test system embodied in a pump control system which control pump speed based upon actual pressure and upon actual pump speed and desired flow rate. The check valve test system disables the portion of the control system which controls pump speed based upon desired flow rate during the test. The test is comprised of timing the time it takes the pump to rotate through the portion of each cycle wherein the check valve is supposed to close and comparing th...

There is disclosed herein a modular, high power, flyback transformer based power supply with step up and step down capability. The power supply uses multiple flyback transformers having switching transistors which may be either connected to one terminal of the primary winding or which may be placed in the center of the primary winding. The switching transistors are driven by pulse trains which are out of phase with each other. This results in lowered RMS values for ripple current through the inp...

There is disclosed herein a system for providing control of multiple functions needed to perform eye surgery. A microprocessor based system controls a pneumatic system for driving pneumatic scissors in either a variable frequency, multicut mode or a proportional cut mode where the cutting pressure is proportional to the position of a foot operated position sensor.