摘要:
A chopper for adjustably controlling the average value of the voltage supplied from a D.C. battery source to a motor load for adjustable speed control. The chopper comprises manually-operable spring-biasing means for applying force to close a contact to energize the motor and electromagnetic means simultaneously energized for re-opening the contact. This occurs at a high repetition rate so that the average value of the voltage across the motor determines the motor speed. This average value of voltage is proportional to the closed-to-open time ratio of the contact and is adjustable by manual control. Two versions are disclosed. In the first version, the spring-biasing force is applied to the contact by depressing a trigger. In the second version, the spring-biasing force is applied to the contact by rotation of a knob. Both versions may use either tension or compression spring force.
摘要:
A cam disc has a dual row of ratchet teeth on the periphery for dual rate of advancement by either of two oscillating motorized advance pawls. The disc has alternating high and low concentric cam tracks formed on one face. A plate is registered on the cam disc hub and has integrally formed plural resilient cam follower arms with each arm having a plastic cam track follower tip molded over the tip. The molded tips make contact with a stationary portion of the plate to limit follower travel when the cam is retracted by user movement of the shaft for setting the cam position. The high and low cam tracks engage adjacent follower arm pairs to effect a drop-to-make and drop-to-break action to each of a plurality of SPDT switches disposed for actuation by the cam followers.
摘要:
An electronic control circuit (10) for a gas oven including a hot surface igniter (24) which is heated through the application of electrical current to a temperature sufficient to ignite gas supplied through an electrically actuable gas valve (26). The applied current is regulated by a micro-controller (20) which controllably gates on a triac (14) while taking into consideration a sensed current level.
摘要:
Various circuits and combinations of radiant energy responsive transducer means such as photovoltaic diodes connected to the gate of a depletion mode FET whose source and drain are connected to the gate and cathode of a thyristor, are disclosed to provide a semiconductor switch which is triggered into conduction solely by a small amount of radiant energy, without the need for a second triggering energy source, and which also affords immunity to unwanted dv/dt and temperature induced turn-on. Various modes of operation are disclosed, including the thyristor self-triggering into conduction, and/or being of the light-activated type itself and being directly triggered by impinging light, and/or being triggered by the light-responsive diode bias, and/or being triggered by a small bias supplied from a second set of photovoltaic diodes connected to the thyristor gate. Other combinations are disclosed providing zero-cross firing.
摘要:
A system is provided for producing plasma pinch X-rays usable in X-ray lithography. Ionized heated plasma is repeatably generated in a first area directly from solid material without exploding the latter. X-rays are generated in a second area by passing high current through the plasma causing radial inward magnetic field pinching. Accurate control and improved intensity performance, and greater flexibility in selection of X-ray emitting materials, are provided by the separation of the plasma generating and the X-ray pinch generating functions. Common electrode structure is provided for plasma generating and for plasma pinching, which common electrode also provides a cylindrical plasma communication passage from the first to the second area, and provides an X-ray emission passage of desired axial orientation.
摘要:
A gate turn-off device is formed by the integration of a power transistor with a lateral thyristor. The thyristor has a split emission path from its emitter, part of the emitter current completing a regenerative loop to maintain conduction after removal of a gating signal, and the remainder of the emitter current supplying base drive to the power transistor to render the latter conductive. In the ON state of the device, most of the load current flows through the power transistor, with only a small holding current flowing through the thyristor. Because of the low level of holding current, the thyristor is easily turned off by a small negative gating signal, breaking the regenerative loop, thus terminating emitter current whereby there is no base drive for the power transistor and hence the device is OFF.
摘要:
A gate turn-off device is disclosed having a load current carrying power transistor regeneratively collector-base coupled with another transistor, and includes a third, shunting transistor providing high gain turn-off. The device is turned ON by signal current of one polarity applied to the base of the power transistor driving the latter into conduction to carry load current, and the device remains ON upon removal of the signal due to base drive supplied by the collector of the other transistor in the regenerative loop. A third transistor is connected to one of the collector-base junctions to shuntingly break the regenerative loop when the third transistor is biased into conduction, thus providing higher gain turn-off. A single ON-OFF control terminal is disclosed, as well as separate ON and OFF control terminals.
摘要:
A system is provided for producing plasma pinch X-rays usable in X-ray lithography. Ionized heated plasma is repeatably generated in a first area directly from solid material without exploding the latter. X-rays are generated in a second area by passing high current through the plasma causing radial inward magnetic field pinching. Accurate control and improved intensity performance, and greater flexibility in selection of X-ray emitting materials, are provided by the separation of the plasma generating and the X-ray pinch generating functions. Common electrode structure is provided for plasma generating and for plasma pinching, which common electrode also provides a cylindrical plasma communication passage from the first to the second area, and provides an X-ray emission passage of desired axial orientation.
摘要:
A Hall effect semiconductor device is provided with means for clipping or focusing emitted carriers to form a centralized columnated beam, and trimming means for accurately controlling the amount of magnetic deflection due to Lorentz force. Emitters from an emitter region travel through a base region under influence of an externally applied drift field toward a pair of spaced collector regions. The polarity of a perpendicularly applied magnetic field determines deflection of the carriers toward one or the other of the collector regions. The columnating means comprises a pair of spaced auxiliary collector regions intermediate the emitter region and the primary collector regions for collecting carriers not within a central angle or cone. A columnated beam is provided by carriers passing between the auxiliary collectors within the central angle or cone. Trimming of the beam is provided by a selectable electric field applied in the same direction as deflection of the carriers to thus control the amount of beam deflection and insure that the beam is directed toward the one or other primary collector.
摘要:
A gate turn-off device is formed by the integration of a lateral SCR and a vertical power transistor operating in parallel, with the latter carrying most of the load current whereby the former may be easily turned off which in turn terminates base drive to the transistor and thus the device is turned OFF.