Abstract: The atomizer of the present invention serves for generating free atoms and an atomic cloud by heating a sample for analysis. The device includes a preferably tubular cuvette for receiving the sample, and the cuvette consists either of a basic body of carbon, which is enveloped by a pyrolytic graphite layer, or only of pyrolytic graphite layers. An electric supply unit for Joule heating the cuvette is in contact with the cuvette by contact members. In order to achieve a radial temperature distribution in the cuvette such that the inner wall of the cuvette is at an essentially higher temperature than the outer wall of the cuvette, the contact surfaces of the cuvette and the contact surfaces of the contact members contact each other in such a manner that the electric current applied during operation of the atomizer preferably flows through the inner wall of the cuvette.

Abstract: A gas shielded arc welding method in which a non-consumable electrode and a filler wire are respectively connected to independent DC power sources and the non-consumable electrode is located in a preceding position, feeding the filler wire from behind the electrode. The non-consumable electrode is held in a forwardly tilted position to form an angle smaller than 85.degree. with a workpiece, and the non-consumable electrode and filler wire are applied with inverse electric currents to thereby control the arc direction for formation of sound joints. A welding apparatus is also disclosed which is capable of effecting arc extension control and oscillation simultaneously.

Abstract: An automatic valve seat build-up welding apparatus for a Y-type main steam isolation globe valve used in an atomic power station is disclosed which is characterized in that the valve seat can be build-up welded on the spot by the welding torch introduced into the valve box with the welding operation being carried out remotely from the spot and viewed by an image sensor positioned near the welding torch so that the exposure of an operator to a radioactive environment is prevented.

Abstract: Apparatus and a method for generating a ramp voltage for use as a control signal in the electrode circuit of an arc welder. The generator includes an integrator whose input is coupled to a current generator by a switching network controlled by switch logic responsive to the output voltage of the integrator itself. The current generator supplies negative and positive currents alternately to the input of the integrator as a function of the actuation of the switching network so that a ramp voltage characteristic can be obtained in which the ramp voltage, once it reaches a maximum value, will fluctuate at a frequency above 20 kHz between upper and lower limits on either side of a mean value such that the mean value will be constant over time.

Abstract: A method of securing a hot wire to holder wires within a carrier body by means of heating and soldering material applied to the holder wires. In this method, holder wires are provided with a layer of soldering material and secured in a carrier body, while in a second operation each holder wire is placed in a tool between conductive poles of an electrical current circuit. In a third operation, the hot wire to be secured in place is placed at each holder wire between the conductive poles of an electrical current circuit which in the fourth operation is operative in a manner limited in duration, until the melting temperature of the soldering material has been attained. The wires are held in place until the melted solder solidifies. The method according to the invention enables the automated contacting of electrically conductive wires such that the connection is capable of withstanding both corrosion and high temperatures.

Abstract: A short circuit transfer arc welding machine including a wire electrode which is fed towards a base metal, a DC source for applying a voltage across the base metal and the wire electrode, a switching element for interrupting the voltage, a voltage detector for detecting a voltage developed across the base metal and the wire electrode, a first comparator for determining when a detection voltage outputted by the voltage detector reaches a voltage value corresponding to the short circuiting of the base metal and wire electrode, a second comparator for determining when the detection voltage of said voltage detector reaches an arc discharge voltage, and a switching element control circuit for closing the switching element in response to a signal from the first comparator and for opening the switching element in response to a signal from the second comparator.

Abstract: An arc blowing control method and apparatus for use in a pulse arc welding system for preventing the extinction of the welding arc in the presence of current fluctuations or the like, thus preventing splattering of molten welding material and resulting in a smooth and continuous welding bead. A detection circuit is provided for electrically detecting the occurrence of a so-called stepped leader phenomenon during pulse arc welding and for generating a stepped leader signal accordingly. A switching unit is operated in response to the stepped leader signal for switching from a normal arc signal output to an arc blowing blocking signal output for a predetermined time. An arc blowing blocking circuit operates in response to the arc blowing blocking signal for effecting arc blowing suppression operations.

Abstract: An arc-welding method, which comprises: arc-welding objects of welding together along the line of a groove formed between said objects of welding by continuously moving a welding electrode along the line of said groove while reciprocating said welding electrode in the width direction of said groove; characterized by: calculating at prescribed time intervals, for each one reciprocation of said welding electrode in the width direction of said groove, deviations (I-Io) of values (I) of one of arc current and arc voltage from a previously set reference value (Io), for each of left-side deviations (L) and right-side deviations (R) relative to the vertical plane which passes through the center of amplitude of said one reciprocation of said welding electrode and is parallel to the line of said groove; calculating at said time intervals, when said welding electrode moves over the left side of said groove relative to said vertical plane, differences (L-R) between said left-side deviations (L) and the immediately prece

Abstract: An infrared detector is provided with spectral filtering means for direct observation of the arc region during electric arc welding operations. The filter permits direct observation of the weld pool by suppressing almost all of the infrared radiation produced by the arc itself. Were this not the case, the electrical signal output from the infrared detector is totally obscured by the intense infrared radiation from the arc and would thus not permit sufficiently high resolution infrared measurements to be made on the weld pool and the work piece.

Abstract: The apparatus comprises a current transformer coupled to the welding tranrmer primary and connected with an analog transmitter of the welding current and with a digital transmitter of the duration of short-circuits in the welding circuit, having a memory element at the output.

Abstract: A system for rapidly soldering wire to terminal pads of a printed circuit board. A soldering tool is heated to a high temperature above 1000 degrees F., and preferably between 1600 to 2000 degrees F., and has a predetermined effective mass for holding a quantum of heat just sufficient to make an effective solder joint over a broad range of terminal pad conditions.

Abstract: Three parameters represent speed, current and voltage are combined to produce an electrical signal representing a desired uniform heat for an operation in which a movable workpiece is involved. A set of electrical signals are developed during the actual operation and combined with the electrical signal representing the standard heat. A resulting error signal and feedback circuit maintain the heat at the workpiece substantially at the desired uniform heat.

Abstract: A method, timing control circuit, and power supply are described for initiating arc discharge between the cover gas delivery shroud and lead wire held in the bonding tool of a lead wire bonding machine for melting and forming a ball at the end of the lead wire. An arc discharge timing control pulse controls duration of the arc discharge within an empirically determined time window between the shortest and longest durations of arc discharge which result in optimal ball formation of a substantially spherical ball at the end of the lead wire without necking of the lead wire above the formed ball. The timing control circuit also provides an initial cover gas movement delay before ball formation for displacing oxygen from the shield and the end of the lead wire, and a subsequent cooling delay for solidifying and cooling the formed ball in the cover gas stream prior to ball bonding.

Abstract: A pulse arc welding apparatus in which pulse current and base current are alternately supplied a welding unit 13 comprises a series circuit of a transistor 2, a reactor 3 and a current detector 4 connected between a single power source 1 and the welding unit, and a control circuit 20 for switching the transistor on and off in response to inputs from the current detector, pulse current upper and lower limiters 7, 8, and base current upper and lower limiters 21, 22.

Abstract: During a weld period the weld parameters are monitored and data representing the weld resistance curve and the power curve are acquired and stored for analysis by a suitably programmed computer. The derivative of R, R is calculated and stored and the function is divided by power P to obtain R/P. The resistance curve is searched to obtain the maximum value R.sub.m which occurs during the heating phase and the function R/P is searched prior to the time of R.sub.m to find the maximum of that curve representing the highest rate of resistance increase. Then the R/P curve is searched subsequent to its maximum to determine when the function reaches a specified percentage of the maximum. That value occurs at the knee of the resistance curve and approximates the onset of melting in the weld.

Abstract: An adaptive control system for welding which senses the lateral profile of a weld joint while the welding electrode moves laterally across the joint, compares a first portion of the sensed lateral profile to a second portion of the sensed lateral profile, and then adjusts a welding parameter, such as the center of oscillation for tracking, the width of oscillation, and constant fill control, in response to the results of the comparison. One disclosed signal processing technique matches an average of data samples for the left portion of the weld seam to an average of data samples for the right portion. Another disclosed technique involves comparing an integrated signal corresponding to the leftward portion of the sensed lateral profile to an integrated signal corresponding to the rightward portion.Another disclosed technique involves comparing an integrated sensed profile signal to a predetermined reference value which is based upon a reference signal.

Abstract: In an arc welding operation seam tracking is accomplished by determining the level of infrared radiation in a selected bandwidth, from at least two points lying in a direction forward of the arc torch travel and on opposite sides of the seam. Signal levels from the infrared detectors are compared and the difference signal is used to laterally position the arc torch. In this way, automatic seam tracking is accomplished thus facilitating robotic welding processes.

Abstract: Apparatus and method are described for rapid ball formation at the end of lead wire retained in the capillary wire holding tool of a ball bonding machine. A circuit is coupled between the cover gas shroud and lead wire for establishing controlled electrical discharge between the end of the bonding wire and the shroud, for melting and forming a ball. The circuit includes a DC power supply for delivering a positive polarity to the shroud and negative polarity to the lead wire for drawing a discharge of electrons from the end of the lead wire to the shroud. A capacitor is coupled in series with the DC power supply for receiving the electrical discharge. An impedance is also coupled in series for limiting the electrical discharge current. Charging of the capacitor limits and shapes the electrical arc discharge to a controlled pulse profile of short duration for rapid ball formation. An electronic gate is also used to control pulse duration.

Abstract: A wire bonder apparatus for use in connecting a conductor wire to a conductive element on a work piece, such as a microelectronic chip or wafer. The bonder apparatus includes a work piece support station adapted to support a work piece observable through a microscope viewing arrangement, and a bonding head having a support arm on which is mounted a bonding tool and selectively movable wire clamping arms adapted to incrementally feed a bonding wire to the bonding tool. The support arm is caused to undergo a ramped movement so as to effect a predetermined progressively increasing contact force between the bonding tool and the work piece. In one embodiment, the clamping arms are adapted for cooperation with actuator means so as to effect incremental stepped arcuate movement of clamping fingers along the path traversed by the conductor wire whereby to lineraly advance the bonding wire when gripped by the clamping fingers.

Abstract: A method and apparatus is disclosed for forming a ball at the end of bonding wire or lead wire held in a capillary wire holding and bonding tool for ball bonding of the lead wire to an integrated circuit chip. The method of ball formation is of the type in which the end of the bonding wire is enclosed in a shroud or shield and the shield and the end of the bonding wire are flooded with an inert cover gas. Ball formation is accomplished by electrically discharging an arc between the bonding wire and the shroud for melting and forming the ball at the end of the wire. A passageway is provided for delivering and mixing hydrogen gas into the inert cover gas delivery line at a location upstream from the shroud sufficient for complete mixing. The rate of flow of hydrogen gas is metered and controlled for adjusting the percent by volume of hydrogen in the cover gas mixture to a desired range.