Design of pulse heating power supply based on energy-peak temperature control

In order to solve problems of uncontrollable peak temperature of pulse heating power supply, slow heating rate and low precision of heating energy control in soldering process, improve stability of temperature control in heating process and realize smooth transition of heating curve, a kind of precision pulse heating power supply based on by energy-peak temperature control was designed. Requirements of load characteristics of power supply and dynamic response characteristics of thermocouple on electrical characteristics of power supply were analyzed. Main circuit and control circuit of power supply system were designed based on inverter converter technology. Digital control system was designed based on high performance STM32 controller. A control algorithm based on energy-peak temperature control was proposed. Output temperature-electrical characteristics of the designed power supply were tested and compared with those of the traditional PID control. Heating temperature distribution characteristics of end face of welding head were tested and micro-patch inductance was used to verify process adaptability of the power supply. The test results showed that the power supply could realize precise control of heating pulse energy, had high precision control of output temperature and time, and could realize precise control of peak temperature under condition of rapid heating up, which effectively restrained temperature overshoot and improved uniformity of temperature distribution of welding head. It could meet requirements of precision control of welding parameters for miniaturization of electronic devices.