Introduction to the functions of components of constant temperature soldering iron
The circuit diagram is designed, and the next step is to arrange the components. The constant temperature adjustable soldering iron is mainly controlled by thermocouples and integrated circuits, with high temperature accuracy, adjustable soldering temperature, and high-strength engineering plastic handle. It is mainly composed of these components: two black and red diodes, soldering iron core, one light-emitting diode, thermocouple, one adjustable resistor, one sensor, HA17358, two electrolytic capacitors, one metal film resistor, and one voltage regulator.
Each component has its own purpose: adjustable resistors are used to regulate temperature, voltage regulators and metal film resistors are used to protect circuits, and electrolytic capacitors are used to filter and convert AC to DC. Thermocouples are used to detect the temperature of the soldering iron core, and when the temperature of the soldering iron core reaches the temperature of the adjustment handle, it stops heating through it.
This is to emphasize the application principle of thermocouple temperature measurement:
The application principle of thermocouple temperature measurement:
Thermocouples are one of the most commonly used temperature detection components in industry. Its advantages are:
① High measurement accuracy. Because the thermocouple is in direct contact with the measured object and is not affected by the intermediate medium.
② Wide measurement range. Commonly used thermocouples can measure continuously from -50~+1600 ℃, while some special thermocouples can measure temperatures as low as -269 ℃ (such as gold iron nickel chromium) and as high as+2800 ℃ (such as tungsten rhenium).
③ Simple construction and easy to use. Thermocouples are usually composed of two different types of metal wires, and are not limited by size or opening. They have protective sleeves on the outside, making them very convenient to use.
a. Basic principle of thermocouple temperature measurement
Weld two different materials of conductors or semiconductors A and B together to form a closed circuit. When there is a temperature difference between the two attachment points 1 and 2 of conductors A and B, an electromotive force is generated between them, resulting in a current of a certain magnitude in the circuit. This phenomenon is called thermoelectric effect. Thermocouples work by utilizing this effect.
b. Types and Structure Formation of Thermocouples
