Abstract: A control system for an automatic vending machine is adapted to set operating parameters such as the selling prices of various commodities. The system includes a microprocessor, associated memory, push-button switches, displays and a control program. For setting the price of a particular commodity the system responds to repeated actuation of certain switches and sequentially increments the values of a particular operating parameter stored in memory and displayed on the display, so that the value of a particular operating parameter can be changed without directly inputting data representing the desired value of the parameter. The operating mode of the machine is changed in a similar manner. The system reduces the number of switches required to change parameter values.

Abstract: A coin sorter has an AC bridge circuit including at least one bridge arm having a detecting coil disposed along a coin passage to detect a plurality of coin denominations. A reactance element, such as a fixed coil or capacitor, is connected in a second arm of the bridge, and a plurality of resistors connected in series are provided in a third arm of the bridge for obtaining fractions of the voltage developed across said third arm in response to the passage of different coins. Differential amplifiers receive the voltages from different taps between the resistors and compare these voltages with a voltage proportional to the voltage across the reactance element. The outputs of the differential amplifiers provide an indication of the coin denomination.