Sound excitation switch working principle diagram The sound excitation switch works, this circuit can be used as a sensor for the burglar alarm, and can also be used to open the * recorder to record the conversation. Adjust R8 to achieve the required sensitivity. LM339 is a four comparator, the first part A1 is used for amplification and detection, and the gain is 100; A2 compares the DC output of A1 with the reference level selected by R8, and its output can trigger Q1 to generate 200mA load current, and Light up the LED.
The first process of Investment Casting production is the manufacture of investment mold, investment mold is used to form the cavity in the refractory shell model, so in order to obtain the casting with high dimensional accuracy and surface finish, the investment mold itself should have high dimensional accuracy and surface finish. In addition, the performance of the melt itself should also make the subsequent shell making process as simple as possible. In order to obtain the above high quality requirements of the investment die, in addition to good pressure (pressing the investment die), but also must choose the appropriate mold material (referred to as the mold) and reasonable mold making process.
The advantage of the investment casting method is that it can cast complex castings of various alloys, especially high temperature alloy castings. For example, the blade of jet engine, its streamlined outer profile and cooling inner cavity, with machining process almost impossible to form. Investment casting process can not only achieve mass production, ensure the consistency of castings, but also avoid the stress concentration of residual blade lines after machining.
The biggest advantage of investment casting is that because investment casting has a very high dimensional accuracy and surface finish, so it can reduce the machining work, just leave a little machining allowance in the parts requiring higher parts, and even some castings only leave grinding and polishing allowance, without mechanical processing can be used. It can be seen that the investment casting method can greatly save machine tools, processing time and metal raw materials.
silica soil casting parts, Precise dimension Tianhui Machine Co.,Ltd , https://www.thcastings.com