Abstract: The invention relates to a wafer transfer system that achieves high efficiency, as measured by throughput rate. This is accomplished in one instance by the combination of reliable transfer of single wafers between ports while being simultaneously rotated to accomplish notch alignment. Another instance allows for simultaneous tilting of a multitude of wafers, such as changing the entire load of a transfer cassette between horizontal and vertical orientations, rather than operating on individual wafers serially. Furthermore, the design of this system renders it usable in both left-handed and right-handed workflow arrangements, not requiring construction of mirror-image systems and thereby achieving an economy of scale in production and inventory of the wafer transfer system itself.

Abstract: The invention relates to a wafer transfer system that achieves high efficiency, as measured by throughput rate. This is accomplished in one instance by the combination of reliable transfer of single wafers between ports while being simultaneously rotated to accomplish notch alignment. Another instance allows for simultaneous tilting of a multitude of wafers, such as changing the entire load of a transfer cassette between horizontal and vertical orientations, rather than operating on individual wafers serially. Furthermore, the design of this system renders it usable in both left-handed and right-handed workflow arrangements, not requiring construction of mirror-image systems and thereby achieving an economy of scale in production and inventory of the wafer transfer system itself.

Abstract: A circuit for indicating the approximate energy content of the most significant transient appearing on an electrical power line within a predetermined interval is disclosed. An input to a first threshold comparator (326) may be set by the user to mark the nominal minimum amplitude (V.sub.2 ) of voltage transient whose energy content (volt-second area) is to be recorded. The transient impulse voltage integrator (401) is turned on when the impulse amplitude exceeds a preliminary threshhold (V.sub.1) lower than the nominal amplitude (V.sub.2) under control of a second comparator (325) and flip-flop (423). When the transient impulse amplitude equals the nominal amplitude (V.sub.2), a latch (431) reading a digital converter (430) at the output of the integrator (401) is clocked to permit display of the accruing integrator. While the integration proceeds the threshold of the second comparator (325) is increased from V.sub.1 to V.sub.