A high power switching circuit is disclosed which utilizes a four-terminal Darlington transistor block to improve switching speed, particularly in rapid turn-off. Two independent reverse drive currents are utilized during turn-off in order to expel the minority carriers of the Darlington pair at their own charge sweep-out rate. The reverse drive current may be provided by a current transformer, the secondary of which is tapped to the base terminal of the power stage of the Darlington block. In one application, the switching circuit is used in each power switching element in a chopper-inverter drive of an electric vehicle propulsion system.

An inductive method and apparatus for forming detached spheromak plasma using a thin-walled metal toroidal ring are described that uses external current leads and internal poloidal and toroidal field coils located inside a vacuum chamber filled with low density hydrogen gas and an external axial field generating coil. The presence of a current in the poloidal field coils, and an externally generated axial field sets up the initial poloidal field configuration in which the field is strongest toward the major axis of the toroid. The internal toroidal-field-generating coil is then pulsed on, ionizing the gas and inducing poloidal current and toroidal magnetic field into the plasma region in the sleeve exterior to and adjacent to the ring and causing the plasma to expand away from the ring and toward the major axis. Next the current in the poloidal field coils in the ring is reversed. This induces toroidal current into the plasma and causes the poloidal magnetic field lines to reconnect. The reconnection continues until substantially all of the plasma is formed in a separated spheromak configuration held in equilibrium by the initial external field.

Patent for a gate lock that automatically locks.

Patent for an attachment that can be connected to a sewing machine to facilitate quilting.

Patent for a device that stretches wire, specifically for fence construction.

Patent for an insecticide to kill red ants and "other noxious insects" (line 9).

Patent for a water or oil well screen to keep mud and other debris out of the barrel of the well.

Patent for a weight motor. This invention is meant for the use of driving fans to circulate rooms. This "invention refers to the winding mechanism wherein a drum on which the cord is wound and the first gear wheel are independently rotatable in one direction on the winding shaft, the latter having keyed thereon two ratchet wheels which engage respectively, pawls on the drum and on the gear wheel" (line 13-20). Illustration included.

Patent for a magazine rifle. This invention consists of a combined breech block and cartridge carrier. Illustrations included.

Patent for an insect destroyer consisting of a steam-generator used with "removable drawers forming the fire-box and ash-pan of the generator, a safety-valve connected with the steam-boiler, and a novel form and construction of flexible discharge-tube, the same being provided with a cut-off device and with a socket-piece adapted to receive a handle by means of which the discharge end of the flexible tube may be elevated and conducted to any desired point" (lines 12-21).

Patent for a lifting jack for car trucks.

Patent for a seat for linemen when stringing telegraph or telephone poles, which has clamps that go around the pole.

Patent for an insertible saw tooth, which does not require the use of a separate holder.

Patent for an insecticide for boll weevils, which is made of oil of sassafras, chalk, water, and sulfate of magnesia.

Patent for a new and improved ventilating chimney. This design consists in "the combination, with the smoke-flue, of the ventilating-flue, the thimble provided with outwardly-projecting lugs and inwardly-projecting apertured lugs, the plate provided with a central aperture and with a flange having notches, and the screws passed through the plate into the apertured lugs" (lines 16-23).

Patent for a tram car. Illustration included.

Patent for a trap gun, which is placed in a trap and fires when bait is disturbed which will only go off when the bait is tampered with and can turn to follow an animals movements in the trap.

Patent for a new propelling device attached to a marine vessel, including illustrations.

Patent for a new windmill using different parts to help regulate the sails and for folding and unfolding the sails, including illustration.

Patent for a pasteboard box with flexible binding that can be used for carrying suits.

Patent for improvements to subsoilers "to provide a subsoiler which has a plurality of pivoted points which will merely loosen the under soil so that same may retain a large amount of moisture, and will not turn the under soil over" (lines 10-15).

Patent for an improvement in tobacco substitutes, by using a combination of ingredients that “will completely destroy all desire for tobacco and thus enables them to discontinue its use without any of the inconvenience or suffering,” (lines 18-21) ingredients of the compound are included. No illustration.

Patent for improvements in projectiles is to positively insure the explosion of the projectile at any desired point and the action is more reliable than is the case with time-fuses, where exact results cannot be insured, or with impact-projectiles, which explode when they come into contact with the armor. (Page 2, lines 12-18) Illustration is included.

Patent for improvements in spark-arresters for smoke-pipes by using a “combination of a bent smoke-pipe having one complete turn downward, a cinder-piper opening into the lowest portion of said turn, and a coarse wire screen titled backward and overhanging said turn, a receptacle having a slanting bottom hinged at the upper end and secured at the lower end by means of a chin passing over a suitable roller and leading to the rear of the boiler,” (p. 2, lines 20-28) illustration is included.