Abstract: A voltage compensation system for an A.C. power line supplying one or more air conditioners, a telephone system or other telecommunication system, a battery charger, or some other utilization system that should have an input voltage within a given normal range. The voltage compensation system includes a transformer unit containing a transformer having at least two windings coupled electromagnetically by a transformer core; one of those windings preferably is in two segments that are connectable in series or in parallel. One winding is connected to an input terminal and to an output terminal. The other winding adds to the A.C. line voltage when the line voltage drops below a low voltage threshold and/or subtracts from the line voltage when the A.C. line voltage exceeds a high voltage threshold. If the A.C. line voltage is in the range required by the utilization system, the other transformer winding is effectively shorted out or otherwise disconnected.

Abstract: An electromagnetic pickup for a musical instrument, such as a guitar, strung with ferromagnetic strings, comprises an elongated laminated ferromagnetic (steel) core long enough to span all of the strings; there are at least four and usually six thin steel laminations in the core. An electrical pickup coil is wound in a coil form, usually plastic, that encompasses the core, and a vertically magnetized main permanent magnet engages the bottom edge of the core. The magnet is preferably formed of a resin impregnated with magnetic particles, is magnetized transversely, and maintains the core at a given polarity. A housing encloses the core, the coil, and the main magnet and provides for mounting the pickup in spaced relation to the strings so that the magnetic field encompasses the strings and string movement generates electrical signals to the coil. Preferably, there are additional permanent magnets to shield the sides of the core. Dual-coil humbucker embodiments of the pickup are described.