Importance

Loading Importance Indicators...

Abstract

A low power coin discriminator detects and identifies the denomination of a coin to activate a parking meter, telephone, or vending machine device. Initially the device is in a low power, dormant state. Insertion of a coin into the discrimator trips a switch which produces a wake-up pulse which turns on a microprocessor. The coin falls upon a piezoelectric element, a signal from which causes the microprocessor to activate a photoelectric sensor. The coin moves through the photoelectric sensor which determines the net cross-sectional area of the coin. The microprocessor samples the output of the photoelectric sensor to detect the minimum light incident upon the sensor at the point of maximum eclipse of the light beam. The microprocessor also samples the output of an integrator which integrates the output of the piezoelectric element to produce a numerical value proportional to the mass of the coin. If the output of the photoelectric sensor indicates that the coin is within acceptable limits then the measured mass of the coin is also compared to the corresponding limits. If the coin is deemed to be valid, its denomination is recorded in a conventional manner. Once the discrimination process is complete the circuit automatically returns to its original low power, domant state.

Loading the Abstract Image...

First Claim