Test method and application of Polyester/cotton Braided Sleeve

Polyester/Cotton Braided Sleeve is one of the basic components of semiconductors, which has the function of current amplification and is the core component of electronic circuits. There are many types of Polyester/cotton Braided Sleeves in China, and the arrangement of the pins is also different. Before use, the braided net tube with the pin arrangement cannot be determined, and there is no instruction manual for the transistor, so it is necessary to carry out the forward and reverse characteristics. Test to determine the correct position of each pin, and clarify the characteristics of the braided network management and the corresponding technical parameters. The following is an introduction to the correct method of forward and reverse characteristic testing:

1. Positive characteristic test: Touch the black test lead of the multimeter to the positive pole of the braided network tube, and the red test pen to touch the negative pole of the braided network tube. If the needle does not reach 0, but stops near the middle of the dial, the The resistance value is the forward resistance of the braided network tube. Generally, the smaller the forward resistance, the better. If the forward resistance value is 0, it means that the die is short-circuited and damaged. If the forward resistance is close to infinite value, it means that the die is broken. Tubes are unusable; 2. Reverse characteristic test: Touch the red test pen of the multimeter to the positive pole of the braided network tube, and the black test pen to touch the negative pole of the braided network tube. If the needle points to an infinite value or close to an infinite value, it is a qualified braided network tube. .
The braided network tube has a strong unidirectionality; under the action of forward voltage, its resistance value is very small, and it is in a conduction state, which is equivalent to a closed switch knife; under the action of reverse voltage, its resistance is infinite, and it is in a cut-off state , like a broken knife. Utilizing the unidirectional characteristics of the braided network management, various logic circuits can be formed. For example, the detection braided network tube plays the role of FM detection in the radio; the variable volume braided network tube is used in the high-frequency head of the TV; 0.7V, germanium tube is 0.3V) Utilizing this characteristic, it can be used as a limiting element in the circuit to limit the signal amplitude within a certain range. The follower braided network management plays a role of follower in the inductance of the switching power supply and inductive loads such as relays.
The structure of the braided network pipe is to use a chip to manufacture two PN junctions. In addition to the semiconductor base, the two PN junction semiconductors are divided into three parts. The middle part is the base area, and the parts on both sides are the emission area and the collector area. There are two PNP and NPN are guided to the corresponding electrodes from three aspects, which are emitter and collector C E B The PN junction between the emitter and the base is called the emitter, and the PN junction between the collector and the base is called the collector electrode. The base area is very thin, while the emission area is very thick and the impurity concentration is high. The PNP type braided network tube emission area emits holes, and its moving direction is consistent with the current direction, so the emitter arrow points inward; the NPN type braided network tube emission area emits free electrons. It moves in the opposite direction to the current flow, so the emitter arrow points outward. The direction of the emitter arrow is also the conduction direction of the PN junction under forward voltage. There are two types of silicon polyester/cotton woven sleeves and germanium polyester/cotton woven sleeves, PNP type and NPN type. The Polyester/cotton Braided Sleeve has a current amplification effect, and its essence is that the braided mesh tube can control a large change in the collector current with a small change in the base current.