Development of comparative electronic circuit for reduced flow valve control. Different types of flow control valves are commercially available but most are only adequate for high flow rates. These arc provided with pneumatic devices to reduce explosion risks in industrial plants. Flow-reduced and low pressure valves are small sized, usually driven by analogical signals and very expensive. Current assay developed an on-line computer-aided flow control electronic system made up of common electronic components within a comparative voltage scheme. A subtracted amplifier was employed in the electronic circuit which compares two voltages for rotation direction control and stoppage of speed engine reducer linked to the common valve stem. This low cost system is very efficient and has the advantage of being electronically assembled without any difficulty. Different sized valves were successfully coupled to the electronic circuit-driven reduction engine which provided flexibility to the developed apparatus. Calibration and time delay determination assays are provided, with lowest flow rates ranging between 0.3 and 3.6 mL s(-1).332185189