摘要:
Aluminum or aluminum alloy scraps or wastes are broken into chips and extruded under a high temperature to produce extruded structural profiles. The method is characterized by the fact that the interior of the extruder is evacuated prior to or simultaneously with the extrusion step so as to exhaust air entrapped in the body of the chips. There is also disclosed apparatus suitable for performing the method.
摘要:
Aluminum or aluminum alloy scraps or wastes are broken into chips and extruded under a high temperature to produce extruded structural profiles. The method is characterized by the fact that the interior of the extruder is evacuated prior to or simultaneously with the extrusion step so as to exhaust air entrapped in the body of the chips. There is also disclosed apparatus suitable for performing the method.
摘要:
An intrusion monitoring apparatus wherein horizontal and vertical sync signals separated from the video signal generated by a monitor television camera are used to produce window pulses having respective timings and lengths corresponding to discrete spots on the video frame screen, said window pulses being used for gating the input video signal, sudden level change of the respective gated video signal portions being detected to provide an audible and/or visual alarm.
摘要:
An apparatus for collecting shellfish and the like comprises a first fence anchored in the ground to enclose a collection area, said fence comprising wall sections of a height to be scaled by shellfish, each of said wall sections having exposed on only the inner surface thereof a pair of vertically spaced conductors spaced less than the length of the shellfish and so as to be in the advancing path of the shellfish scaling the wall section from the inner side thereof. Means are provided for applying intermittent voltage pulses continuously to the conductors which pulses are spaced apart a time interval less than the time required for the shellfish to span the space therebetween.
摘要:
A regulating transistor is connected between a constant current load and a constant voltage load. A control circuit responds to voltage variations of the constant voltage load to adjust the transistor whereby a constant current and a constant voltage and supplied to both loads. In a vidicon camera circuit a focusing coil presents a constant current load and a heater element presents a constant voltage load.