Electronic price conversion and display system adapted for installation on existing mechanical fluid dispensing pumps

摘要

An electronic price conversion and display system adapted for installation on existing mechanical fluid dispensing pumps wherein sensors are mounted within the dispensing pump so as to be responsive to a plurality of angular position indicators disposed to rotate in fixed relation with the lowest order number display wheel of the pump's mechanical transaction price display. The number of indicators, preferably marks or slots placed directly on the lowest order number display wheel, are chosen in accordance with a desired price conversion. A display unit, which has a digital transaction price display and which is preferably placed on top of the pump for easy viewing, houses an electronic circuit which counts the passage of angular position indicators and increments the digital transaction price display to a reading corresponding to the indicator count. The digital transaction price display is made up of individual display digits and a logic circuit is provided in the display unit for suppressing the "O's" displayed by the higher order digiits until the higher order digits are needed to register price. The display of the display unit can be reset by a second sensor adapted to detect the transition of the pump motor current when the motor is switched on.