Trouble phenomenon: Once the stepper motor is started, the external fuse of the stepper motor driver will burn out, and the device cannot operate.

Failure analysis: During the inspection, the maintenance personnel found that a power tube was damaged, but because there was no information, the role of the tube was not clear. He thought it was a power-driven pre-push, and replaced it with a power tube. After the power was turned on, the insurance was once again It burns, and the replaced pipe is also damaged. In order to further improve the high-frequency response of the drive system, stepping motor drive can use the frequency-up and boost power drive interface. The voltage provided by this interface to the windings has a linear relationship with the operating frequency of the motor. Its main circuit is actually a switching stabilized power supply, which uses a frequency-voltage converter to convert the frequency of the driving pulse into a DC level, and uses this level to control the input of the switching stabilized power supply, which constitutes a frequency feedback Power drive interface. After inspection by professional maintenance personnel, the initial analysis is correct, that is, the fuse is repeatedly blown, there must be an abnormal high current in the drive, and a power tube is damaged. But the role of the tube is not clear. In fact, this tube is a stepping motor power supply drive tube, and the stepping motor starts with high voltage, so it has to withstand high voltage and large current. Static inspection found that in the circuit of the pulse ring distributor, the resistance from the power supply to the ground is very small, but there is no short circuit (the current does not pass through the electrical appliances, and the power is directly connected to the two poles).

According to the number of components in the circuit and its power consumption analysis, the resistance from the power supply to the ground should not be so small, so it is suspected that there are components in the circuit damaged. The stepper motor driver can control the angular displacement by controlling the number of pulses, so as to achieve the purpose of accurate positioning; at the same time, it can control the speed and acceleration of the motor rotation by controlling the pulse frequency, so as to achieve the purpose of speed regulation and positioning. Stepper motor is a kind of induction motor. Its working principle is to use electronic circuit to convert direct current into time-sharing power supply. Multi-phase sequential control current. Use this current to power the stepper motor, and the stepper motor can work normally. The driver is a time-sharing power supply for the stepper motor, a multi-phase sequential controller. Power-on inspection found that a chip (also known as a microcircuit) was abnormally hot. After power off, cut off the power pin of the chip, statically check, the increase of the resistance from the power to the ground should be normal. The resistance value from the power supply of the chip to the ground is very small. Check the model of the chip, it is a non-standard model, which is not found in many manuals.