Nowadays, more and more patches are used for circuit boards of welding machines, because of its high efficiency and low cost. At present, most welding machine maintenance personnel are still very unfamiliar with the patch. They have long been accustomed to plug-in components, and generally reject the soldering machine of the patch.

Our drive power supply is often used, and chip capacitors often fail. Especially mass-produced power supplies. Here are a few common reasons for your failure, and how to avoid them.

We know that the three major accessories of CPU, memory, and graphics card directly determine the performance of the whole machine. Whether the purchased motherboard can provide a sufficient and stable power supply environment for these three accessories has become a very important factor. The power supply circuit of the CPU is usually composed of three parts: capacitors, inductor coils, and field effect transistors (MOSFET tubes). In addition to providing a more pure and stable current for the CPU, it also acts as a step-down current limiter to ensure the normal operation of the CPU. In the power supply circuit of the motherboard, the higher the specifications of the capacitor and the inductor coil and the more the number of FETs, the better the quality of the power supply circuit.

Measure the resistance between electrodes. Put the multimeter in the R×100 or R×1K block, and test according to the six different connection methods of the red and black test pens. Among them, the forward resistance values of the emitter junction and the collector junction are relatively low, and the resistance values measured by the other four connection methods are all very high, ranging from several hundred thousand ohms to infinity. But whether it is low resistance or high resistance, the inter-electrode resistance of the silicon triode is much larger than the inter-electrode resistance of the germanium triode.

SMD capacitors, also known as SMD capacitors, surface mount capacitors, are usually yellow, black or light blue in appearance. It can be divided into two types: non-polar and polar. This article mainly discusses the difference between the positive and negative poles of polarized chip capacitors.

The area of the circuit board is limited. In order to better realize the function and facilitate maintenance, electronic components usually appear in the form of letter codes + numbers. In order to standardize electronic circuits and facilitate use, generally speaking: the meaning of letter codes and the ordering of numbers are regular.
A simple example to illustrate: