Abstract: Remanent ground response is induced by rapid high current in a transmit coil. The transmit coil remains at zero current for a sufficient time for the remanent ground response to be sensed in a receive coil. A rapid high voltage and a sustained low voltage establish and maintain a stable current in the transmit coil followed by a zero current period. The sequence is repeated with a stable negative and followed by positive currents and a zero current. The receive coil is repeatedly interrogated at zero current between switch closings connecting in the transmit coil. Combined ground remanence and target eddy current signals are received during the constant current periods, and the ground remanence signals sensed during zero transmit coil current are subtracted from the combined signals.

Abstract: A metal detector has a large primary transmit coil, a small primary feedback bucking coil, a first receive coil, and a second receive coil. A variable resistance device is connected to the first and second receive coils. A voltage source is connected to the large primary transmit coil. The voltage source is oppositely connected to the small primary feedback bucking coil. A primary voltage is provided to the large primary transmit coil. A reverse primary voltage is provided to the small primary feedback bucking coil. The small primary feedback bucking coil is positioned near the first and the second receive coils. The metal detection methods and apparatus sums up the signals from the two secondary coils. One is over nulled, the other is under nulled. They are close enough to an inductive null to attenuate the stray coupled signals from the primary driving signal and detecting the object.

Abstract: A constant current is provided to an energizing coil in a magnetic detector by charging a capacitor through a resistor from a high voltage source. Discharging of the capacitor into the energizing coil quickly increases current in the energizing coil. After the capacitor is switched off, a low voltage source maintains current constant in the energizing coil. The coil discharges its energy as a negative voltage to the capacitor. A high negative voltage source tops off the capacitor. After a delay, the capacitor discharges a negative current into the energizing coil. A negative low voltage source maintains the negative current. The negative voltage source is disconnected, and the coil discharges positive voltage into the capacitor. The high voltage source tops off the capacitor with positive voltage to repeat the cycle.

Abstract: This invention provides a pulse induction metal detector where a coil transmits a pulsed magnetic field to energize metal objects that are often buried or hidden in a matrix (ground) containing ferromagnetic minerals. A difficult challenge is to detect and identify the metal object while ignoring the ferromagnetic matrix. Techniques are presented for achieving this.

Abstract: A new hybrid metal detector combines induction balance and pulse induction technologies. Target signals are generated from a transmitted wave that has both induction balance and pulse current inducing characteristics and uses pertinent sampling of the receive data. Combining the two data sources provides eddy current target identification while excluding ground permeability and remanence obscuration.

Abstract: A new hybrid metal detector combines induction balance and pulse induction technologies. Target signals are generated from a transmitted wave that has both induction balance and pulse current inducing characteristics and uses pertinent sampling of the receive data. Combining the two data sources provides eddy current target identification while excluding ground permeability and remanence obscuration.

Abstract: A pulse induction metal detector having high efficiency and sensitivity. Within the scope of the invention is a high efficiency hand-held metal detector for detecting a metal object, comprising a coil and a source of current flow in the coil. The source is adapted to produce one or more pulses of current in the coil. Preferably, at least two of the pulses are spaced apart in time at least about 20 microseconds during which current flow in the coil is substantially constant. The metal detector also comprises a detecting circuit for detecting a response to the current pulses, and a sampling circuit for sampling the response at predetermined times at least during the time of one of the pulses.

Abstract: The present invention is an electric vehicle power system that uses multiple permanent magnet motor/generators connected in series or parallel and multiple battery step switching. Motor, torque and speed are controlled by steps in series connection and then in parallel connection. Smooth acceleration, regeneration and current control are provided by delaying stepping from one battery step to the next until the next step is fully engaged. Transients are limited to the effect of one battery step by using rectifier shunt switching. Multiple motors provide acceleration torque at low speed in series connections and at cruising speeds in parallel connection. Regenerative deceleration is provided in the opposite manner. Battery depletion is averaged by flipping ends of a battery bank. Controls are provided with normal foot controls and a speed setter. A separate deceleration pedal or lever may be used.

Abstract: A pulse induction metal detector having high efficiency and sensitivity. Within the scope of the invention is a high efficiency hand-held metal detector for detecting a metal object, comprising a coil and a source of current flow in the coil. The source is adapted to produce one or more pulses of current in the coil. Preferably, at least two of the pulses are spaced apart in time at least about 20 microseconds during which current flow in the coil is substantially constant. The metal detector also comprises a detecting circuit for detecting a response to the current pulses, and a sampling circuit for sampling the response at predetermined times at least during the time of one of the pulses.

Abstract: A flash phase analysis circuit provides parallel phase channels for simultaneously analyzing a detected signal in each of several phase windows and providing parallel outputs indicating whether a target falls in one of the phase windows. In one implementation, the parallel outputs each drive a segment of an output device to indicate the target type to the user. The flash phase analysis circuit divides a detected signal among the phase windows and then simultaneously compares the measured signal at each phase window with a reference signal. The circuit matches measured data with pre-selected phase characteristics corresponding to known targets in parallel and provides parallel output signals indicating target type.

Abstract: A flash phase analysis circuit provides parallel phase channels for simultaneously analyzing a detected signal in each of several phase windows and providing parallel outputs indicating whether a target falls in one of the phase windows. In one implementation, the parallel outputs each drive a segment of an output device to indicate the target type to the user. The flash phase analysis circuit divides a detected signal among the phase windows and then simultaneously compares the measured signal at each phase window with a reference signal. The circuit matches measured data with pre-selected phase characteristics corresponding to known targets in parallel and provides parallel output signals indicating target type.

Abstract: Turning on either headlights or parking lights pulses a first control circuit and energizes a relay, closing normally open contacts in the light circuits. The closing of the contacts energizes a second control circuit which holds the relay on and supplies power to timers. Turning off an ignition switch starts a short headlight timer and a long parking light timer. The timers have outputs connected to disable the second control circuit and to thereby de-energize the relay. The output of the short timer is grounded through the headlights when the headlights are in a low resistance off condition.

Abstract: Carburetor air-fuel mixtures are directed to a manifold having a plurality of long, small diameter helical tubes extending upwardly therefrom. An auxiliary air inlet having an auxiliary choke and an auxiliary air throttle supplies air to mixtures entering the tubes in response to engine temperature and carburetor throttle.Heated engine coolant flows upwardly through a jacket enclosing the tubes. An outlet manifold receives air-fuel mixtures vaporized in the tubes and directs them to the engine intake manifold. The carburetor is mounted on a block having an air-fuel passageway extending from a top inlet to a side outlet. The block is mounted atop a block having a passageway having a side inlet which receives vaporized air-fuel mixtures from the tubes to a bottom outlet in communication with the intake manifold.

Abstract: Air compressed by a windmill-driven compressor is stored as liquid in an underground cryogenic insulated tank. Pressurized air released from the tank is vaporized by a refrigerant circuit, heated, and used to operate an air motor which drives an electrical generator. Heat of compression extracted by compressor coolant heats vaporized air entering the motor and heats water stored in a ground-level tank located directly above the cryogenic tank. Solar and fossil fuel heating circuits further heat vaporized air entering the motor. Motor exhaust is used as a coolant in refrigeration circuits. The inlet and outlet conduits to the cryogenic tank are arranged to effect heat exchange. The windmill has a vertical axis rotor with curved blades mounted in a vaned housing.

Abstract: A yaw control device automatically aligns a windmill. A spur gear displaces a motor-driven worm gear mounted between balanced springs when an external turning moment is applied to the windmill. Displacement of the worm gear moves an actuator arm positioned between switches in the motor power supply circuit, closing one of the switches and thereby activating the motor to drive the spur gear in opposition to the turning moment. An idler gear can be operatively positioned between the spur and worm gears. The worm gear is mounted on the rotatable shaft of a bracket pivotally connected to the spur or idler gear axis or is mounted on splined shaft rotatably supported by fixed bearings. The actuator arm is rigidly connected to the worm gear bracket or is pivotally mounted adjacent the worm gear. In an alternative embodiment, the worm gear is connected to the windmill for movement therewith about a fixed spur gear.

Abstract: A motor vehicle is operated with a hot gas power system which includes a compressor which compresses air in normal driving when being driven by the motor and upon slowing or running down hill when being driven by vehicle momentum, a storage tank which holds the compressed air and a heat exchanger which cools the compressed air and supplies the removed heat to heat air as it is released from a storage tank to the motor. An additional heater is used where required. When required, fuel is added to the compressed air and the mixture is ignited and combusted before entering the motor.

Abstract: An automatic headlight switch for automatically turning off headlights of a vehicle a predetermined period after the ignition switch is turned off consisting of a timer coupled to the ignition switch which is started by a transient pulse from the ignition switch being turned off which after the predetermined period is coupled to a relay solenoid for deactuation thereof opening relay contacts in series between the battery and the headlight switch. Upon turning on the headlight switch, a pulse generator coupled thereto which is triggered via a transient from the headlight switch actuates the relay solenoid and thereby applies power to the headlights through the relay contacts and the headlight switch.