常用的工频电阻焊机输出不连续的类正弦交流波形，由于电流过零时间长，同等功率下电流峰值过大，造成焊接时工件加热不连续，易产生飞溅，针对上述问题，设计了一种基于数字信号处理器(DSP)的逆变交流控制系统． 该系统以 DSP 为控制核心，包括信息检测、脉宽调制(PWM)输出控制、人机交互、输入输出(I/O)接口、故障检测等电路和相应的控制软件． 系统采用 PWM 控制方式调节焊接变压器的初级电压，实现了大范围电流调节条件下较为连续的输出;具有电流、电压、功率 3 种反馈控制模式和多种频率选择，在每半个周期内实现快速反馈调节，提高了控制精度，改善了交流电阻焊机的工艺适应性．

Single-phase AC resistance welder provides alternating current similar to sine-wave． Due to the long zero-crossing time and high peak current，welding heating becomes discontinuous and splash occurs easily． In order to solve these problems，a control system for AC resistance welding，which takes DSP(Digital Signal Processor) as the controlling core and is composed of information detection，PWM (Pulse Width Modulation) output control，human-computer interaction，I/O (Input/Output) interface and fault detection circuits，is developed，and the correspond-ing software is also designed to assure system function． By employing PWM control to adjust the primary voltage of welding transformer，a relative continuous output in wide current range is ensured． The control system possesses three feedback control modes respectively in terms of current，voltage and power，provides several output frequen-cies，and implements quick and stable output control in half a period． Thus，both high control precision and adaptive welding process can be achieved．