Abstract: An enhanced variable impedance transformer is disclosed for controlling the power from an alternating input power source to a load in accordance with a direct current control signal. The variable impedance transformer comprises a first and a second annular saturable reactor core and an annular power core with a power input winding being simultaneously wound about the annular power core and the first and second annular saturable reactor cores. A power output winding is wound about the annular power core for transferring power to the load. The power input windings are connected to the alternating input power source for establishing a magnetic flux in the annular power core and in the first and second annular saturable reactor cores.

Abstract: An improved narrow profile transformer and method of making is disclosed comprising a primary winding and a secondary winding with the secondary winding being interleaved with the primary winding. The primary and secondary windings are spiral winding with all portions of the primary and secondary windings intersecting a geometric plane extending through the narrow profile transformer. The primary and secondary windings of the narrow profile transformer may be encapsulated within a polymeric material.

Abstract: An apparatus is disclosed for a combined transformer and inductor for transmitting power between a source and a load. The apparatus comprises a transformer core and an inductor core which are magnetically independent from one another. A primary winding is wound about the transformer core and is electrically connected to the source by a primary connector. A secondary winding is wound about the transformer core and is electrically connected to the load by a secondary connector. An inductor coil is wound about the inductor core and is interposed in series with one of the primary and the secondary windings. A plurality of air gaps are interposed in the inductor core for providing an inductance in one of the primary and secondary windings. The air gaps are uniformly distributed about the inductor core for uniformly distributing heat generated at the air gaps about the inductor core.

Abstract: An improved narrow profile transformer and method of making is disclosed comprising a primary winding and a secondary winding with the secondary winding being interleaved with the primary winding. The primary and secondary windings are spiral winding with all portions of the primary and secondary windings intersecting a geometric plane extending through the narrow profile transformer. The primary and secondary windings of the narrow profile transformer may be encapsulated within a polymeric material.

Abstract: An apparatus and method is disclosed for an improved variable impedance transformer for controlling the power from an alternating input power source to a load in accordance with a direct current control signal. The invention comprises a DC control winding simultaneously wound about a plurality of saturable reactor cores and a plurality of AC power input windings simultaneously wound about a power core and each of the saturable reactor cores. A power output winding is wound about the power core for delivering power to the load. A low impedance equalizing winding is wound about the saturable reactor cores for shunting any resultant alternating voltage as a result of physical variations between the saturable reactor cores.

Abstract: A phase controlled regulating circuit for a portable spot welder having an output transformer, utilizes a normally saturated transistor across one diagonal of a diode bridge circuit to interrupt the connection between the control voltage source and the regulating source, in response to a timer input.

Abstract: A battery charger in which full-wave rectified current is supplied to a battery through a silicon controlled rectifier. By controlling the gating of the SCR the average charging current is controlled. An oscillator circuit formed by a unijunction transistor with a timing capacitor in its emitter circuit provides the necessary gating pulses. The charging rate of the capacitor is controlled to alter the period during which the SCR is conductive. This control of the charging rate is provided by a circuit responsive to battery voltage and by a circuit responsive to charging current. A portion of the battery-voltage responsive circuit acts to short-circuit the capacitor to stop charging in the event that the battery is connected with reverse polarity. A high charging-rate mode is controlled by a timer circuit which overrides the normal voltage and current control circuits.