The display screen is connected to the QC-PC-C01 controller . Thus, a Peltier element can be specifically controlled, so that a desired temperature is reached and maintained on an object. The display shows the actual temperature and the target temperature. By means of buttons, the display of the controller for cooling or heating can be set. In addition, the temperature display can be justified The display delivers a voltage signal of 5 V at a resistance of 10 k (0.5 mA) on reaching the target temperature Below the target value, the voltage signal is 0 V. An LED below the display lights up when the controller supplies power to the Peltier element The power supply for the display is done via the controller.