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Troubleshooting method for stepping motor driver of woodworking engraving machine

by:Transon     2020-03-30
Woodworking engraving machine stepper motor driver fault response method the fault phenomenon is: once started, the external fuse of the driver will be burned and the equipment will not run. During the inspection, the maintenance personnel found that a power tube was damaged, but because there was no information, they could not figure out the role of the tube. They thought it was the front push of the Power Drive. After the Power Tube was switched on, the insurance was burned again and the replaced pipes were also damaged. After inspection by professional maintenance personnel, the initial analysis is correct, that is, the insurance is repeatedly blown, the driver must have an abnormal large current, and a power tube is damaged. But the role of the tube is not clear. In fact, this tube is a stepper motor power drive tube, and the stepper motor starts at high voltage, so it has to bear high voltage and large current. Static inspection shows that the resistance from the power supply to the ground in the Circuit of the Pulse ring distributor is very small, but there is no short circuit. According to the number of components in the line and its power consumption analysis, the resistance value from the power supply to the ground should not be so small, so it is suspected that the components in the line have been damaged. Power-on inspection, found a chip abnormal fever. Cut off the power supply pin of the chip after power failure, static check, the increase of resistance from power supply to ground should be normal. The resistance value of the power supply to the ground measured by the chip is very small. Check the model of the chip, which is a non-standard model and has not been found in many manuals. After line analysis, it is confirmed to be the main component in the board: ring pulse distributor. In order to further confirm the problem of the chip, first change the stepping motor power supply drive tube with the same withstand voltage current power to restore the power supply pin of the chip, the light emitting diode circuit is used to replace each winding of the stepping motor as an analog load. After the power is turned on, the light emitting diodes are all bright, that is, all the windings are powered on, which does not meet the requirements of the line, and the input stepping pulse does not respond, so it is confirmed that the chip is damaged. However, the chip is not available in the market. Under the condition that the space in the driver shell allows, a ring pulse generator is designed by using the combination circuit, that is, the combination of the existing D trigger and NAND gate, made on a small printed board, remove the original chip and install the small printed board on the pad of the original chip through pins. The LED is still used as the analog load, and after the power is turned on, the stepping pulse is added to emit light in sequence. Dismantle the simulated load, access the host, power on, and the equipment is running normally. This example shows that maintenance personnel should not only be able to analyze phenomena (Overcurrent), Find out the more obvious reasons (Power Tube damage), We should also be able to analyze the initial cause of the failure step by step (Pulse generator damaged) , And can use the existing component combination on hand to replace the device problem that is difficult to solve.
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