Abstract: An intelligent test head which can be plugged into an existing computer-controlled automatic test system that is adapted to carry out certain tests on integrated circuits and discrete devices, the test head making it possible for the system to execute special tests which the system is otherwise incapable of performing. The existing system includes a main frame computer associated with a programmer. A device under test is linked by a pin electronics board to the computer through a relay interface board which acts to selectively couple a forcing supply, a function generator or other testing sources to the device, which sources are appropriate to the normal test capabilities of the system. When plugged into the system, the intelligent test head is interposed between the pin electronics board and the device then under test.

Abstract: A voltage source adapted to excite a gas-ionization electrode so as to generate copious amounts of ionized gas without, however, producing measurable amounts of undesirable reactive or toxic chemical by-products. Yielded by the source is a unipolar voltage wave having a steady state DC component which, though below the ionization potential, serves to condition the gas to promote ionization. Imposed on the steady-state component is a gas-ionization component in the form of low-frequency surges, each composed of a short series of high-frequency pulses having a brief duration and an extremely high peak amplitude. The duration of the surge pulses is insufficient to break down the gas chemically, but the amplitude thereof is such as to effect intense gas ionization. The steady-state component prevents the electric field from collapsing completely in the intervals between pulses, thereby keeping the gas at a level approaching its ionization potential.

Abstract: An ion projection head designed to provide a fairly uniform cloud of ions over a wide area for use in therapeutic and industrial applications, among others. The head, although being relatively small, generates a large ion cloud in a very efficient manner. A point electrode is located in a cup having a spherical internal surface of curvature. This cup causes the ions to move in a relatively common direction. An iris plate over the mouth of the cup causes the ions generated in the cup to be propelled away from the iris plate.

Abstract: A filter cassette is disclosed, for use in an air filtering system, which has a central supporting frame, inside of which an electrostatic filtering device is mounted, and on each side of which are carrier flanges adapted to receive separate removable filtering elements. The entire filtering cassette is designed to be removed from the air filtering system for servicing; and the filtering elements supported by the carrier flanges may be varied in different installations to suit the specific filtering needs.

Abstract: A blower is mounted in an enclosure; having a first opening covered by a filter media and a second opening; in such a way that the rotating axis of its blower wheel, or rotor, is: (a) located at or near the vertical midway point between the top and bottom of the enclosure, or duct, in which the blower is mounted, and (b) angularly displaced from the usual horizontal orientation (i.e., horizontal axis of rotation of the blower) by a substantial angle, preferably 15.degree. to 75.degree..