Abstract: A high efficiency controlled direct current source for operating high pressure mercury or metal halide lamps for use as substitutes for ordinary incandescent lamps. The circuit includes a voltage sensitive circuit for pulsed starting of the arc discharge lamp as well as for the activation of an auxiliary incandescent filament during the warm-up or hot restart of the arc.

Abstract: A weatherproof cover assembly includes a housing and a pivotally attached cover in a configuration in which no gasket is required between the cover and the housing. The housing includes a base having an aperture therethrough, an outer wall and an inner wall. The cover includes a flange which is located between the inner and outer walls when the cover is closed. The cover, the inner and outer walls, and the flange together inhibit entry of liquids into the assembly. A hinge construction for pivotal attachment of the cover to the housing includes a cylindrical opening in the cover and a pivot insert attached to the housing. A cylindrical torsion spring, having end loops on a diameter thereof, is retained in the hinge by slotted posts in the cylindrical opening and on the pivot insert. The cover pivots about sleeve portions of the pivot insert.

Abstract: A light source, including a high pressure discharge lamp and a starting pulse generator, such as a spiral line pulse generator, utilizes a generally straight elongated conductor, or starting aid, in close proximity to an outer surface of the discharge tube to provide efficient coupling of the starting pulse to the discharge lamp. The starting aid extends between a region proximate one of the electrodes and a region proximate the other of the electrodes. The starting aid provides within the discharge lamp an ionization path of minimum length free of circumferential turns when the conductor is energized by the pulse generator. The starting aid can be affixed to the discharge tube or can be mounted in one or more support brackets.

Abstract: A power supply provides high voltage for a grid controlled x-ray tube. In the supply an oscillator generates a high frequency signal which is amplified and transformed to kilovoltage. A voltage multiplier increases the kilovoltage to a potential suitable for the tube. The voltage multiplier includes a bank of series capacitors which tends to maintain a constant high voltage when the tube is not conducting.

Abstract: A method for fabricating a gate-source structure for a recessed-gate static induction transistor. The method is characterized by use of doped polysilicon to fill the recessed gate grooves after the gate grooves have been etched and diffused. The gate grooves have depth greater than width and therefore the surface of the polysilicon layer deposit is substantially planar. The planar surface allows photolithographic techniques to be used for formation of gate contact regions and for depositing of metal gate and source electrodes.

Abstract: One or more dental instruments are connected by flexible supply lines to a dental unit. A retractor is arranged to pull an extended instrument back to the unit upon being triggered. The dental instrument carries a magnet. A magnetic sensor is located near the retractor. When the instrument is passed near to sensor a signal activates the retractor which pulls in the instrument.

Abstract: In a foot control, two or more pivoted pedals have a common main spring which provides the same resistance to all pedals. A bias arrangement keeps one pedal from falling down if the other pedal is depressed. A bias arrangement may be a horizontal rod associated with each pedal. The rod is spring biased against the pedal at a location below the pivot axis.In a two pedal embodiment both pedals can control a single electrical element. A stud extends from each horizontal rod. The stud normally prevents a spring biased pivoted member from pivoting and actuating the electrical element. When a pedal is depressed, the corresponding rod and stud move to allow the pivoted member to actuate the electric element and a corresponding switch.

Abstract: A light source wherein a spiral line pulse generator, having an output coupled to one electrode of a metal halide discharge lamp and an input for coupling to a source of lamp operating power, provides high voltage, short duration lamp starting pulses. The spiral line pulse generator includes two conductors and two insulators, each in the form of an elongated sheet, in an alternating arrangement which is rolled together in a spiral configuration having a plurality of turns. The high voltage, short duration pulse is provided upon closure of a low inductance switch coupled between the conductors. A thermal switch can be utilized to bypass the spiral line pulse generator after lamp starting. The spiral line pulse generator can be enclosed within the lamp base of the light source.

Abstract: A dental delivery unit carries a number of dental instruments in nests. Upon selection, one nest is extended carrying its instrument to the dentist's group. Selection is accomplished by a priority system. Associated with each nest is a switch. Activation of any switch starts a selection period by a priority system. At the end of the selection period the nest corresponding to the last to be activated switch is extended by the priority system.If two switches are activated together the nest corresponding to the furthermost switch is extended.

Abstract: A high frequency amplifier utilizes series-connected transistors to achieve high voltage class C operation. High frequency input power is coupled to the gate of a first FET which is normally biased off. The source of a second FET is coupled to the drain of the first FET. The drain of the second FET, which forms the output of the amplifier, is coupled through a radio frequency choke to a supply voltage. The gate of the second FET is dc biased at about one half of the supply voltage. A capacitor coupled between the gate of the second FET and ground controls the level of high frequency power applied to the second FET. The amplifier can be operated at a dc voltage which is approximately equal to one half the sum of the individual breakdown voltages of the serially connected FET's.

Abstract: Energy-saving circuitry for a rapid-start fluorescent lighting system includes a reactance-modifying capacitor coupled in series with first and second fluorescent lamps and includes a filament switch which is operative to conduct filament heating current during starting of the first lamp. The filament switch is coupled between filaments at opposite ends of the first fluorescent lamp and triggers to a low impedance state in response to the lamp starting voltage. A capacitor bypass switch can be coupled in parallel with the reactance-modifying capacitor to reduce the impedance of the series circuit during lamp starting.

Abstract: A method of manufacturing glass-lined tube. An undercoat of glass is fused onto the surfaces of nozzle-shaped flange-pieces, from their outer peripheral edges to their molded and curved inner faces, welding flange components then welded to either end of the metal tube to form a complete flange at each end. The inner faces of the weld zones are then shaped by grinding and polishing. A glass tube that is greater in length than the metal tube is fitted loosely into the latter tube. The glass tube is supported at either end within the wells of conical caps which are fitted around the flanges by air-permeable spacer-rings, with the ends of the glass tube extending beyond the outward faces of the flange joints and with the glass tube being securely positioned at the center line of the metal tube.

Abstract: A power supply provides direct current to electrodes attached to a patient. The positive electrode is at least partially silver and releases silver ions as a result of the electric current. Silver ions have known bactericidal properties and may be used to treat infected living tissue. Tissue may, however, be damaged by voltages in excess of 1.1 volts. Accordingly, the power supply has two modes. Under normal conditions the power supply has a constant current output. If the voltage between the electrodes reaches a reference voltage of not more than 1.1 volt, the output is changed to a constant voltage mode, abruptly limiting the output voltage. A mode indicator may be incorporated in the supply.

Abstract: The heating of a tunable-acoustic optical filter (TAOF) results in a drift in the calibration of the TAOF as the acoustic-optical medium temperature varies. In practicing the invention, the TAOF is periodically locked to a reference wavenumber and a calibration correction is then derived and employed to keep the TAOF consistently accurate.

Abstract: A voltage supply for an X-ray tube provides both high and low voltages to the tube. A high voltage transformer using split primary and secondary windings is employed. The high voltage is switched on and off by selectively phasing the voltage across the transformer's secondary coils. Low voltage is coupled from one of two primary windings.

Abstract: A controller for process control has an adaptive gain. The controller is used as part of a closed feedback loop, and will, in response to different variables, maintain a constant loop gain regardless of non-linearities in the system.Signals representing the variables are transformed into corresponding active gain factors. The active gain of the controller is computed as a function of the product of the active gain factors and then translated to an output signal. One or more active gain factor is defined as having a first gain factor, at least one breakpoint, and a second gain factor. If two breakpoints are used, a base gain is interposed. Furthermore, one or more variables may have a step function as an active gain factor.

Abstract: In an electrosurgical device, a RF generator is pulse modulated during coagulating procedures. Pulse repetition rate is varied allowing the occasional interjection of relatively wide pulses of RF energy while still allowing sufficient cooling time to avoid cell volatilization. The result is efficient coagulation with minimal cutting.

Abstract: The transmission characteristics of an etalon are varied by changing the angle of incidence of the light beam on the stationary etalon. As examples of the invention, the etalon may be preceeded by a rotatable mirror or a Bragg cell, either of which is arranged to deflect the light beam. The stationary etalon may be used as an optical element in an instrument.

Abstract: A combination process sensor for use in electrically non-conducting lined steel vessels has a tantalum body containing a temperature sensitive element. One end of the body is positioned to be in contact with a product undergoing a process in the tank. Upon this end of the body there is fabricated an electrode, which allows the galvanic sensing of any faults which may occur in the glass lining.

Abstract: A circuit for use with a X-ray tube applies filament power to preheat the tube prior to the application of high voltage. The preheat duration is made to be in inverse relation to the line voltage. The desired result is when the tube starts to conduct the tube current and tube voltage is held within acceptable limits regardless of line voltage variations.