Abstract: A system and method for determining vendibility in an automatic vending machine, comprising: a coin sorter, coin detectors for sorted coins, coin reservoirs for sorted coins, empty switches provided to the respective coin reservoirs, said coins comprising three kinds of coins, 100 yen, 50 yen and 10 yen coins, a change pay off mechanism for paying off change using said reserved coins in said reservoirs, commodity price setting means, a counter for counting the number of received 50 yen coins, a counter for counting the number of received 10 yen coins, a signal generator for generating information of the total amount of received coins based on coin detecting signals, a signal generator for generating unit information associated with 10 yen, and a subtractor for sequentially subtracting said unit information from said total amount information, wherein availability of received coins as change is determined at each stage of said sequential subtraction, whereby vendibility for the respective amount at each stage o

Abstract: A radio-controlled vehicle having a steering motor, a drive motor, a drive mechanism, and a direction sensor for receiving an RF signal from a remote station to actuate the drive motor and to control the steering motor to direct the vehicle to the station. Also, an ultra-sonic anti-collision circuit for preventing the vehicle from colliding with any obstacle lying in the way of its travel. The direction sensor includes an integrating circuit to remove noise components from the direction control signal to thereby provide precise control to the drive mechanism. The ultra-sonic anti-collision circuit includes circuits for preventing malfunction of the anti-collision circuit due to mechanical shocks and/or vibrations of the vehicle.

Abstract: An improved high speed switching circuit having at least an emitter grounded switching transistor, a first resistor connected between the base of said transistor and an input terminal, a second resistor connected between said base and the ground, a plurality of series connected diodes connected between the input terminal and the collector of said transistor has been disclosed. The ratio of the resistance of the first resistor to that of the second resistor is determined in accordance with the number of said series connected diodes.

Abstract: An improved D. C. power source whose output voltage is independent of changes in temperature is disclosed. Compensation for changes in temperature is established by three features. For a change of the voltage drop in the forward direction between the base and the emitter of a transistor, a plurality of diodes provided in a bias circuit in the transistor are utilizied; for a change of the current amplification factor .beta. of a transistor, an additional transistor is attached to the transistor, and; for a change of the value of an emitter resistor connected between the emitter of the transistor and the ground, an external stable resistor is utilized. The D. C. power source of the present invention is, in particular, useful for an integrated circuit.