Patch processing which good how to choose

Usually, the transistor is used as an amplifier to use, because of the good characteristics of PNP transistor, in a variety of transistors are selected to complete the design, the following patch processing manufacturers to explain how to put ambassador crystal tube signal and patch processing which is good how to choose the relevant knowledge.

1. How to choose the SMT patch processing

Nowadays, in Shenzhen, there are many patch processing manufacturers, these manufacturers are uneven in quality, the price is not the same, so before production, must choose a suitable patch processing plant. So, Shenzhen patch processing which is good? Below, Xiaobian from several angles to help you screen, I hope to help you.

I. High degree of professional cooperation

Patch processing is one of the most important links in the whole process of electronic production. The higher the professional cooperation of the patch processing plant, the better the quality of PCB board and the faster the production speed. Therefore, we must choose the professional cooperation high Dongguan patch processing manufacturers. So, how to choose? Through talking with the management or boss of the patch processing plant, observe their attitude and philosophy of doing things, or learn about the reputation and service of the patch processing factory through the third party.

Two, quality management

At present, in order to reduce the price and attract customers, many of the patch manufacturers in Shenzhen do not hesitate to play a hand in quality, reduce QC personnel or do not equip with AOI testing and other means. In this way, even if the price is reduced, but the quality is not good, it will also affect the future use. Therefore, when evaluating patch processing manufacturers, it is necessary to observe whether there are QC personnel or other testing means in their warehouses, and whether engineering personnel have sorted out quality detection management methods and files. Only after a comprehensive understanding can we ensure the final quality.

Three, staff style

Although the employee style is only a part of the reference, it can also explain certain problems. For example, in a patch processing factory, see the employees are negative, sad face, such manufacturers produced products quality rate is certainly not high, and if the employees are very good every day, the work is meticulous, the quality of the products produced by such manufacturers has a great guarantee.

4. Evaluate certain factors appropriately

When choosing Shenzhen patch processing manufacturers, some people will have their own judgment criteria and factors, such as factory size, SMT equipment, quotation, service, etc., which are indeed good measurement factors. However, Xiaobian to remind you that these factors can be referred to, but not absolute. For example, the scale of the factory, small-scale SMT patch processing manufacturers may not be able to produce your products, large-scale manufacturers may not be able to complete the order in time. Take a look at the price, because the price is high to PASS off the manufacturer's practice is very irrational. You know, although the offer is not unique standard, but there is a certain amount of truth. After all, it is impossible for manufacturers to lower prices without guaranteeing costs. In general, good patch processing manufacturers have a relatively fixed source of customers, do not need to constantly look for, only poor companies will constantly look for customers. When you cannot judge whether this company is suitable, you can know whether it is a high-quality Shenzhen patch processing manufacturer by knowing how many old customers his family has and how often they cooperate with him on average.

2. How to emit the crystal oscillator signal

Normally, transistors are used as amplifiers. The characteristics and basic applications of transistors are described in the preceding section. Due to the good characteristics of PNP transistor, in a variety of transistors were selected to complete the design. The output power of 4011 and non-gate chip is only enough to light up a LED, can not be connected to make a small speaker sound, but it can make the triode conduction work, so as to vibrate sound, modify the circuit to insert the PNP type 3906 transistor correctly in the position shown in circle 32-1.

Think about why choose PNP type 3906 transistor? Figure 32-2 illustrates the high level of bow 11910 when the circuit is not working. At this point, the voltage in both directions prevents the current from passing through, and the bottle leds are not bright. In other words, the high level of the bow IMI10 output shuts off the 3906 body triode, thus preventing the supply voltage from passing through and reducing battery loss. When the circuit is connected to the power supply, the speaker should not make sound (except for occasional momentary sound). If the noise continues, cut off the power supply to check the circuit. After that, switch on the circuit, and you can hear a distinct noise. However, as long as the circuit is turned off, the voice hoarse. Operating principle citation 10 low level makes the II body tube on, after :1 transistor output voltage and current increase. 2 The power of the speaker coil increases.

The magnetic force produced by the coil becomes bigger. ■ Increase the vibration of the loudspeaker so as to improve the mute output sound. If NPN type 3904 transistor is used, as shown in Figure 32-3. When the circuit is not working, the high level of the lead coil 10 makes the triode on, and the power supply voltage is directly grounded through the speaker coil. Then, the battery will be very quick. Now let's start making noise.

Choose Kingford SMT proofing patch processing 9 reasons! 1, free of steel mesh fee, boot fee, engineering fee, others charge us free; 2, proofing customers free to send capacitance resistance, save time to find materials; 3, proofing 24 hours delivery, expedited 8 hours delivery, the network proofing delivery is the fastest; 4, 9 quality detection and control system, quality fine hammer refining, guaranteed; 5. 2,000 square meters of dust-free workshop, 20 sets of new imported Yamaha equipment, strength factory 6. Accumulated cooperation of 30000+ R & D proofing, small batch proofing customer witness; 7, live online video, thousands of miles away to see Xiaoming sample production workshop; 8. The minimum charge for a patch is 88 yuan, and the national SF Express is free of mail; 9. One-to-one specialist service, real-time viewing of product production progress on the website;