江苏春晨电缆有限公司生产，变频器的直流电压检测电路不外乎以下两种电路形式。一是输入自直流回路的530V直流电压采用电阻分压、线性光电耦合器隔离和运放电路处理后，输出到CPU；二是由开关电源电路的次级绕组电压整流而出，该路整流二极管在开关管饱合导通期间，承受正向偏压而导通，整流电压输出正比于开关变压器初级绕绕组输入的直流回路的供电。电压采样电路所得的直流电压检测信号，一是提供直流电路过、欠压的报警依据；二是此模拟电压信号输入CPU，也参与对三相输出电压的控制；三是电压检测信号，也同时作为直流电路制动开关管的控制信号。在直流电路电压达一定幅值时，启动制动单元（开关管），将制动电阻接入直流电路，对电压增量部分进行快速耗散。本机的直流电压检测信号，也取自开关电源变压器的次级绕组的整流电压，经排线端子CNN1/CON2（CNN1为电源/驱动板上排线端子序号；CON2为CPU主板上排线端子序号，但排线引脚一致）的25脚引入到CPU主板上来。
The DC voltage detection circuit of frequency converter is more than two kinds of circuit forms. The first is that the 530V DC voltage input from the DC circuit is output to CPU using the resistance partial voltage, the linear optocoupler isolation and the operation of the amplifier circuit, and the two is output to the secondary winding voltage of the switching power supply circuit. It is proportional to the power supply of the DC circuit input to the primary winding of the switching transformer. The DC voltage detection signal obtained by the voltage sampling circuit, one is to provide the alarm basis for the over and under voltage of the DC circuit; two is the analog voltage signal input CPU, and also participates in the control of the three-phase output voltage; three is the voltage detection signal, and also as the control signal of the DC circuit brake switch. When the voltage of the DC circuit reaches a certain amplitude, the brake unit (switch tube) is started, the brake resistor is connected to the DC circuit, and the voltage increment part is quickly dissipated. The DC voltage detection signal of this machine is also taken from the rectifying voltage of the secondary winding of the switch power transformer. The 25 foot of the line terminal CNN1/CON2 (CNN1 is the serial number of the line terminal on the power / drive board; CON2 is the serial number of the line terminal on the CPU main board, but the line pin is consistent) is introduced to the CPU main board.
前级电压检测电路来的信号，经R81引入到W1半可变电阻的中心臂，经W1调整、R82分压后，输入到IC9（LF353高输入阻抗双运放电路）的3脚，由1脚输出后，一路经D7嵌位直接送入CPU引脚；一路输入到IC9的6脚，IC9的5脚为R85、R86对+5V的分压值，此电压作为基准电压。当直流电路电压升高到一定幅度时（如660V）， IC9的6脚电压高于5脚基准电压，IC9的工作状态反转，7脚输出低电平，BRK制动电路工作指示灯点亮；一路送入IC10运算放大器的反相输入端2脚，该放大器（电压比较器）的同相输入端3脚，也有+5V经R88、R89分压形成的电压，2脚与3脚电压相比较，2脚电压高于3脚分压值时，从1脚输出一个低电平信号给CPU的35脚，使变频器报出过电压故障信号。
The signal from the front stage voltage detection circuit is introduced into the central arm of the W1 semi variable resistor via R81. After W1 adjustment and R82 partial pressure, the signal is input to the 3 foot of the IC9 (LF353 high input impedance dual amplifier circuit). After the output of the 1 foot, the one road is directly sent to the CPU pin through the D7 inlay; the one is input to the 6 foot of IC9, and the 5 feet of IC9 are R85 and R86 to R85. The voltage is used as the reference voltage. When the voltage of the DC circuit rises to a certain extent (such as 660V), the 6 foot voltage of the IC9 is higher than the 5 foot voltage reference voltage, the working state of the IC9 is reversed, the 7 foot output is low, the BRK brake circuit work indicator light is lit; the one way into the IC10 operational amplifier's reverse input end is 2 feet, and the amplifier (voltage comparator) is in the same phase input end 3 The foot is also the voltage formed by the +5V R88, R89 partial pressure. The 2 foot is compared with the 3 foot voltage. When the 2 foot voltage is higher than the value of the 3 foot pressure, a low level signal is output from the 1 foot to the 35 foot of the foot to make the frequency converter report the overvoltage fault signal.
