Liquid flow ratio control apparatus - has impeller driven by flow of liquid with signal generator outside conveying area

摘要

The liquid dosing agent is proportionated according to the rate of flow of the liquid with an impeller driven the flow of liquid. A dosing pump is controlled by means of a counting arrangement operated via the impeller. A signal generator arranged outside the area conveying the liquid and activated by means of the impeller produces counting signals for the electronic counting arrangement, which includes a Schmitt trigger connected to transistors and a resistor-capacitor timing circuit. The transistor is fed through a Zener diode. Constant potential is maintained across the counting circuit capacitor by the use of a unijunction transistor.