Repairing the maintenance skills of switching power supply

　　Author ：Iflowpower – Portable Power Station Supplier

At the time of the spot, in recent years, both domestic is still international, there is a considerable development, and the switching power supply company has also increased a lot. This leads to many open source power supplies production of switching power supplies quality. This also causes a lot of users who have a lot of damage to the switching power supply.

In fact, these switching power supplies have no big problems. Some small businesses can not be closed. They do not have the strengths of talents in the three-in-one senior business, naturally cause switching power supply design and quality problems.

Production manufacturers of switching power supplies, according to Sanqi. Whether it is a large company is still a small plant, the switching power supply can basically meet the necessary users. Mainly still damaged by users in terms of users.

It is indeed understanding that the normal component loss is. But once the item is damaged, most users will not waste time even if they will repair, and they don't have time or no tool materials. In short, the difference is that the switching power supply is either throw away from buying, or send it back to the original repair, even if the manufacturer, the store received the maintenance of the switching power supply is almost ok.

This article is only a simple introduction to the maintenance method of the switching power supply: 1. When repairing the switching power supply, first detect whether the power components break through the short circuit, such as power supply rectifier bridge, switch tube, high frequency high power rectification pipe; Suppressing the high power resistance of the surge current. Then detect if the electrical port resistance is abnormal, and the above components need to be replaced if it is damaged.

The switching power supply is not hitting, generally checking if the switching frequency is correct, the protection circuit is blocked, the voltage feedback circuit, the current feedback circuit is no problem, the switch tube is breakdown, etc., first check if the fuse is blown, then observe the internal situation of the power supply, If it is found that there is ambident or component rupture on the PCB board, you should focus on the component and related circuit components. Wonder whether there is a confusion inside the power supply, check if there is a charred component.

The voltage of the high-pressure capacitor is first used in a multi-use. If it is a failure caused by the switching power supply or the switching pipe opening, most of the cases, the voltage across the high pressure filter capacitor has not been discharged, this voltage has more than 300 volts, it is necessary to be careful. Measuring the positive and reverse resistance of the AC power cord and the capacitor charging of the AC power cord are measured.

The resistance value should not be too low, otherwise there may be short circuit inside the power supply. Capacitor should be charged and discharge. The load is disengaged, and the ground electrical resistance of each group is measured.

When normal, the clinic should have a capacitor charge and discharge swing, and finally indicate the resistance of the discharge resistance of the road. 2, transformer fever or "嗞嗞 嗞"Sound, generally the switching frequency is wrong;. Generally switching tubes, charging resistors, rectifier diodes are relatively bad .

so generally use digital multimeter quantity, no bad detection. If you look at the surface, you can see if there is a bad break. If there is a timely cut-off supply to overhaul.

Measuring there is no 300 volts output at both ends of the high pressure filter capacitor, if there is no key to search the stream diode, filter capacitance, etc. Measuring the high-frequency transformer secondary coil has no output, if there is no key to check whether the switch is corrupted, whether or not, the protection circuit is moving, if there is, it should focus on the rectifier diode, filter capacitor, and three connections in each output side. Pressure relief.

If the power is started, the power supply is in a protected state, and the voltage of the PWM chip protection input feet can be directly measured. If the voltage exceeds the specified value, the power source is in a protected state, which should focus on the cause of protection.