Alarme de température en kit

This kit can be used for electronic technology Foundation and skill teaching practice, electronic skill teaching, electronic technology teaching, digital circuit teaching, electronic enthusiasts and beginners practice.
The kit contains a complete set of components, circuit boards, supporting drawings, and component lists. (Note: The kit is not a finished product and needs to be welded and installed by the customer!)
Board size: 5 * 3.5cm; Power supply voltage: DC 5V; Weight: 10g

1. Function introduction:
RP1, R1, R2, R3, and RT constitute bridge for measuring temperature in the circuit. When the temperature is below the preset temperature, the potential of 2 feet of UA741 is higher than 3 feet, and the output of 6 feet of 741 is low level. LED1 is on, and the buzzer does not sound, which means no alarm. When the temperature rises, the resistance of RT drops 741. The 2-foot voltage drops with it. When the 2-foot voltage is lower than the 3-foot voltage, the 6-pin outputs a high level and starts to alarm. LED1 goes off.

Welding precautions:
1. The PCB board is printed with silk screen marks of various components. Please compare the silk screen marks and weld them;
2. Resistance has no direction, but there are different resistance values, please pay attention to distinguish when welding;
3. Electrolytic Capacitor. LED lights are divided into positive and negative poles. Long feet are positive (+) and short feet are negative (-). Pay attention to the silk screen direction on the PCB board when welding;
4. When connecting wire to wire holder, pay attention to distinguish positive and negative poles, and do not reverse.