Abstract: Vehicle guidance and control systems that use the intensity of a field radiated from a source of radiation to define the track or lane for operation of the vehicles. The source of radiation used is a single source of radiation in the sense that vehicle position relative to the source of radiation is sensed by sensing intensity of the radiation at the vehicle, rather than the difference in field intensity sensed from two physically separated sources of radiation. Exemplary embodiments using a single magnetic field for navigational control are described, including a basic system for a single vehicle, a tethered system having steering and speed controls for creating a multiple vehicle racing environment, and a radio controlled system, also for creating a multiple vehicle racing environment and in the embodiment disclosed, also useable as a stand alone RC controlled vehicle.

Abstract: Vehicle guidance and control systems that use the intensity of a field radiated from a source of radiation to define the track or lane for operation of the vehicles. The source of radiation used is a single source of radiation in the sense that vehicle position relative to the source of radiation is sensed by sensing intensity of the radiation at the vehicle, rather than the difference in field intensity sensed from two physically separated sources of radiation. Exemplary embodiments using a single magnetic field for navigational control are described, including a basic system for a single vehicle, a tethered system having steering and speed controls for creating a multiple vehicle racing environment, and a radio controlled system, also for creating a multiple vehicle racing environment and in the embodiment disclosed, also useable as a stand alone RC controlled vehicle.

Abstract: A system, method and apparatus for charging rechargeable battery packs. A battery charger has a means to measure a voltage and a battery temperature and a means to determine a rate of increase in battery temperature of a rechargeable battery pack. The battery charger to fast charge if the voltage and battery temperature indicate its safe and to terminate the fast charge in response to the charge condition. Methods include measuring a battery temperature of the rechargeable battery pack and determining a rate of increase in battery temperature during fast charging to determine a charge condition, One method further includes terminating fast charging if the rate of increase in battery temperature exceeds a maximum rate or if the increase in battery temperature rises non-logarithmically. Another method further includes terminating fast charging in response to the charge condition.

Abstract: A system, method and apparatus for charging rechargeable battery packs having redundant safety systems. A battery charger has a temperature sensor at a negative charging terminal for determining the charge condition of a rechargeable battery pack and controlling a charging current. The battery charger has a microcontroller to control the charging of the rechargeable battery pack using a fast charge current or a trickle charge current. Independent safety systems provide safe operation of the battery charger if the microcontroller operation fails. A rechargeable battery pack has a pair of openings to allow direct contact to a positive pole and a negative pole of the end batteries for improved temperature sensing by a battery charger.

Abstract: A system, method and apparatus for charging rechargeable battery packs having redundant safety systems. A battery charger has a temperature sensor at a negative charging terminal for determining the charge condition of a rechargeable battery pack and controlling a charging current. The battery charger has a microcontroller to control the charging of the rechargeable battery pack using a fast charge current or a trickle charge current. Independent safety systems provide safe operation of the battery charger if the microcontroller operation fails. A rechargeable battery pack has a pair of openings to allow direct contact to a positive pole and a negative pole of the end batteries for improved temperature sensing by a battery charger.

Abstract: In accordance with the method, first and second substantially parallel conductors are placed along a pathway and coupled to a controller in a manner so that each may carry a current independently controllable by the controller. A sensing coil is placed in a vehicle having a coil axis approximately perpendicular to the plane of the conductors so as to sense the varying magnetic field caused by varying currents through the two conductors. The controller repetitively provides a half-cycle of current of a given frequency in one of the two wires, immediately followed by another half-cycle of current of the opposite polarity or direction in the other of the two wires.

Abstract: A voice track is recorded on one track of a dual track recording device, typically a tape recorder. On a second track of the recorder an animation signal is recorded characterized by the signal having a frequency at any given time indicative of the then currently desired animation condition. A character is provided having a tape playback unit therein for playing back such pre-recorded dual track tapes, the character having an amplifier and speaker for reproducing the audio information, and a servo motor having a drive system for driving the character mouth elements and eyes with the desired animation, the drive system having a feedback device thereon for providing a feedback signal to the servo motor control. The electronics in the character which is responsive to the animation control signal provided by the playback unit to provide the servo motor drive signal effectively updates the servo motor drive signal on each cycle of the animation control signal received from the playback unit.

Abstract: A toy doll which responds with spoken words and/or sentences to the touching of selected portions of the doll by a user and/or voice actuation by the user is described. Specific areas of the doll, such as eyes, ears, nose, etc. are provided with touch switches. When one of the switches is activated, the doll responds with one of two randomly selected sentences related to that part which was touched e.g. "that's my nose", "do you like my nose". In addition, voice actuation is provided by a microphone located within the doll. When the user speaks to the doll, the microphone senses the speech. After the speech has stopped for a fixed period of time (usually one second) the doll responds with a randomly selected sentence. Audio responses are stored via ROM in circuitry within the doll. The vocabulary of the doll can be changed or enlarged with additional ROM's. In order to conserve power, a gravity switch is provided to turn the doll on when the doll is placed in a sitting position or otherwise moved.

Abstract: An arbitrary number of member computer stations are inter-connected by a "party" communication network. Each member station is normally in a high impedance Monitor Mode, for monitoring in-coming messages. The incoming messages latch the monitoring stations into a Receive Only Mode for preventing "interrupts" of on-going communications. Each station continuously monitors the input impedance from the network, to determine when the network is available for transmission. Member stations may enter the low impedance Transmit Mode only when the network is available, because all of the other stations are in the Monitor Mode. A high Z from the network indicates to each station that the network is available. A low Z indicates that another station is in the transmit Mode, and is in control of the network. The random entry of two (or more) parties at the same time is resolved by a Pre-Transmission Test Cycle.