SMAKN&reg; DC 12V 1-Channel Voltage Comparator LM393 Comparator Module new Working voltage: 12V DC Working current: 30mA Module purpose: automobile current modification circuit, industrial equipment, laboratory testing, application testing circuit. Reference voltage input voltage through precision resistor divider to obtain the reference voltage module, input voltage value determines the range of the reference voltage value, included in the input voltage is 12V, then the reference voltage adjustable range is 0-12V