SYSTEM OF AUTOMATIC MILK SOURING Russian patent published in 1996 - IPC

FIELD: dairy industry. SUBSTANCE: invention is intended for automatic of process of continuous cultivation of milk-acidic organisms. System includes circuit of level regulation, circuit of temperature regulation, circuit of regulation of pH of milk. Circuit of pH regulation of milk has clock pulse generator, additional pulse generator, change-over switch, reversible counter, code-to-voltage converter, analog key, power amplifier, RS flip-flop, differential amplifier, source of calibrated voltage, controlled frequency generator, univibrator and two AND gates. Output of clock pulse generator is connected to input of univibrator which output is connected to second inputs of AND gates. Output of differential amplifier is linked to input of controlled frequency generator which negative output is coupled to first input of first AND gate and which positive output is connected to first input of second AND gate. Output of first AND gate is connected to one make contact of change-over switch. Output of second AND gate is linked to other make contact of charge-over switch. Number of pulses passing through AND gate from controlled frequency generator with coming of one clock pulse is proportional to value of output signal of differential amplifier. Consequently output signal of code-to-voltage converter changes by value proportional to error signal between specified and actual value of pH. EFFECT: reduced usage of starting material, enhanced productivity. 1 dwg