Abstract: A docking system that allows a Teradyne J750-type tester to be mounted to both a probe station and a handler using uniform docking hardware. Any desired probe stations may be converted into an A-type configuration so that the J750 may be used on both probe stations and handlers. In one aspect, a head stage is designed to mount uniform docking hardware to convert a probe station to an A-type configuration. In another aspect, the uniform docking hardware includes two separate mounting assemblies. One of the mounting assemblies has two kinematic docking units placed thereon. The other of the mounting assemblies has a single kinematic docking unit. The separate mounting assemblies allows ease of assembly to the probe station and is less costly to manufacture.

Abstract: The invention is a welding torch with a control means on the torch itself for adjusting welding current. This control means has a thumb button which can be actuated by the welder to turn the torch on or off and to adjust the current to an appropriate value for the weld being made. A latch means at one extreme of its travel is provided to hold the thumb button in the off position. This prevents the torch from being accidentally actuated by inadvertently moving the button.

Abstract: The present invention is a tungsten inert gas or similar welding torch which is readily adjustable in length for different welding situations. The torch has a relatively conventional head with a heat shield attached at the lower end. The heat shield serves as a resilient telescopic mounting for the gas cup which surrounds the electrode. It further serves to give thermal and mechanical isolation between the torch head and gas cup. A gas diffusion screen pack is located within and bears against an inner circumference of the gas cup to provide resilient support and center the cup about the longitudinal axis of the electrode. The gas cup may be extended or retracted a limited distance within the heat shield and may also be rotated if desired. Alternatively, longer or shorter electrode collet bodies can be screwed into the head to provide almost unlimited adjustment of torch length. A gas cup of appropriate length is used with each collet body.

Abstract: An easily replaceable ventilated external insulator for a tungsten inert gas, plasma, or similar welding torch comprises a generally cylindrical member molded from a resilient heat resistant electrical material such as a silicone rubber. The inner wall of the insulator has a plurality of parallel alternating grooves and lands. The grooves communicate at each end with circumferential grooves which act as manifolds. At least one of these circumferential grooves has a vent to release to the atmosphere any gases formed between the insulator and the body of the torch head during welding operations. The vent is located so that these gases are directed away from the weld zone and do not act to contaminate the welding atmospehre.

Abstract: The present circuit controls the high current delivered to a load from a direct current (d.c.) power supply through a pair of power silicon controlled rectifiers (SCRS). For each power SCR there is also employed an associated current conduction control SCR. Each of the current conduction control SCRS acts, when triggered, to terminate the current conduction of its associated power SCR. Each current conduction control SCR is controlled by the provision of current thereto during conduction and non-conduction half cycles of an alternating current source, which operates independently of the d.c. power supply. Accordingly, the occurrence of a current (load) transient, even though it may provide an abundance of current to either of said power SCRS, will not prevent the termination of the current conduction of said power SCR for an excessive period after it should have been turned off.

Abstract: An emission control circuit for an internal combustion engine having a voltage generating circuit connected to a source of direct current energy at a first potential for generating an output voltage of a substantially higher potential, the voltage generating circuit including energy storage means coupled to the output of the voltage generating means for storing an electrical charge. A triggerable switching means is provided for coupling the energy storage means in series with the primary winding of an induction coil, and triggering means responsive to the opening and closing of ignition breaker points is provided for applying triggering signals to the triggerable switching means. The triggering signals accommodate discharging of the energy storage means through the primary winding for a certain predetermined time period. A comparator circuit is provided which includes two semiconductor amplifier circuits, each having a pair of output electrodes and a control electrode.