To control cooling, Samovar can use automatic water supply, regulating the flow of water fed to the dephlegmator. The pump output is controlled with PWM. A PID controller is used to hold the set water temperature.
The principle of controlling a DC motor speed with a PWM controller is quite simple: voltage is applied to the motor winding for a short time and the motor starts to spin up, then the voltage is removed. By choosing the right period during which voltage is applied, you can maintain the speed you need.
Using the PID algorithm, Samovar drives the pump to hold the set temperature, which is defined in the sketch, in the Samovar_ini.h file
//Water temperature that the PWM controller will hold; also, when power is switched off, if the water temperature is below TARGET_WATER_TEMP - 15, the water supply is shut off
#define TARGET_WATER_TEMP 48To build an automatic cooling system you will need a pump with a power supply, a solid-state relay, a water valve, and a tank that the water will be drawn into. The pump will take cooling water from this tank.
Pump wiring diagram
