In the production process of the light-emitting display products, the products need to be sintered several times at different temperatures through the tunnel furnace. Because the production process has higher requirements on the sintering temperature, the temperature control accuracy has a great influence on the product quality, the qualification rate and the consistency. Therefore, furnace temperature control is particularly important. The traditional manual-meter temperature control method has many shortcomings. The tunnel furnace computer control system SA bus, STD bus, PCI bus and so on. These bus standards have their own merits, and it is hard to say who is better than who. A particular bus may outperform another bus for the specific performance/functional requirements of different application objects and objects. Because ISA bus has rich software support, CPU function, various I/O templates on the market is extremely rich, and has a variety of high-end graphics display control card and its supporting software is complete, industrial PC is relatively inexpensive, PC networking is extremely Convenient, industrial PC function upgrade is convenient, high reliability and so on. Therefore, the system selects the Advantech time optimal control mode supporting the ISA and other buses. 3.2 Signal acquisition board 3.2.1 Front-end signal processing board 010 is used as the multi-channel thermocouple temperature acquisition and signal conditioning board. The PS-010 front-end signal processing board is a front-end signal processing board and a multi-channel secondary board for use with the PC-6360 modular interface card. The board is equipped with 16 double-ended input channels and terminal blocks. Through the cascade connection of cables, a PC-6360 modular interface card can be expanded to up to 128 dual-ended input channels (8 PS-010 boards). The high performance instrumentation amplifier provides 1 to 10 (1) times (gear, hardware selection) amplification gain, or user-defined gain. The board also has signal processing functions such as filtering, current and voltage conversion, etc., which are available for users to choose. The PS-010 front-end signal processing board provides a reference junction compensation (CJC) circuit, making this board especially suitable for signal processing in thermocouple temperature measurement systems.
3.2.2 A/D converter board with multi-channel 12-bit A/D interface card temperature conditioning. The A/D conversion result on this card is 12-bit word length. It also has 4 digital inputs and 4 digital output interfaces and three 16-bit word count/timers, and a 1MHz reference clock. The A/D conversion start mode of the card can be selected by program triggering, timer automatic triggering, and external synchronization triggering. The conversion status can be queried by degree, or the CPU can be notified of the conversion result by interrupt. At the same time, the card also has a timed interrupt and an external trigger interrupt for the user to choose. This card can be directly used with the PS-010 front-end signal processing board to easily amplify and collect the weak signal output from the thermocouple sensor. Each PC-6360 multi-function modular interface card can connect up to 8 front-end signal processing boards such as PS-010, that is, 128 analog signal inputs.
3.2.3 photoelectric isolation switch output interface card backward switch output board. Considering that the "on" and the card in the output of the switch are optical isolation technology, the computer and the live signal are completely isolated, which improves the anti-interference ability and the damage resistance. PC- 6407 card switch output is 32-channel two-group common ground mode, with automatic clear function after power-on and host reset. The maximum output current of each channel is 200mA, but the total output current of each group should not exceed 2A. Because the power of the bidirectional thyristor of this system is large, the working current is more than 100A, the gate drive current is above 100mA, and the PC-6407 board can be directly used. Overloaded, thus damaging the board. Therefore, the PC-674 plus the solid state relay SSR is further driven, and then the triac operates. The SSR is a four-terminal, weakly controlled, non-contact power control component that has many advantages and is replacing traditional electromagnetic relays.
The 6320 is used as an A/D converter board for motor speed. Although the system uses the electromagnetic speed controller to control the motor speed, the motor speed also needs to be sampled by PC-6320A/D and displayed on the microcomputer. The PC-6320 features single-ended 8-channel 8-bit A/D conversion and 2-channel 8-bit D/A conversion.
4 system control algorithm 4.1 digital filter design Because of the random interference, the measured signal is mixed with useless components, the filter is used to filter out the useless components in the signal to improve the signal quality. Analog filters are difficult to implement at low and very low frequencies, while digital filters do not have these problems. They are characterized by high precision, high reliability and high stability. Therefore, the system uses the average value of anti-pulse disturbances. The composite filtering algorithm performs filtering. It first uses the median filtering algorithm to filter out the pulse interference in the sampled values, and then performs the moving average filtering on the remaining samples. This method is compatible with the advantages of the two filtering methods, so it is a slow change process. Variables, or fast-changing process variables, can have a better filtering effect.
4.2 Design of Digital Controller 4.2.1 Time Optimal and Integral Separation Dual Control Algorithm for PID Control The system uses a time-optimal (B-B control) and integral-separated PID control dual-mode control algorithm. Time optimal control can speed up the adjustment, while PID control can meet the tracking accuracy and steady-state error requirements.
Time optimal control mode is time optimal control mode| The tunnel furnace is a large inertia system with pure hysteresis. If the conventional PID control is used, when the system starts up, the set value is changed abruptly, or a large disturbance is encountered, the controller is severely saturated due to a large deviation in a short time. The system will experience large overshoots and long periods of oscillation. The use of integral separable PID control can better solve this problem. The basic idea is: when the temperature deviation is large, the integral action is cancelled, and only the PD adjustment is performed; only when the deviation is within a certain range, the integral action is added to perform the PID adjustment. The governing equation can be derived as a threshold value whose value needs to be finalized during commissioning according to the control accuracy. 4.2.2 Fuzzy PID control algorithm due to space limitations, omitted to introduce, specific algorithm please see
Silicone Hand Sanitizer Holder
No kids are "excited" to wash their hands... Make it FUN! And protect your children from getting sick at school and elsewhere by using their favorite design with our colorful jelly wrap silicone empty carriers. Make hand sanitizing FUN and keep the doctor away!
PERFECT PARTY FAVORS: Offer as party favors in goody bags, Easter eggs, Birthdays, PTA student gifts, stockings stuffers and much more!CONVENIENT: 1 - Oz flip top cap bottles attache to purses, backpacks, key chains, gym bags or diaper bags. Wherever life takes you. EASY TO FILL! Convenient flip cap allows for easy filling from any large pump bottle.
COMES EMPTY: YOU CHOOSE - We all have our preferred brands, simply purchase your favorite design and fill with your choice of hand sanitizer gel or lotion. It`s that easy!
YDS are specialized in Silicone Bottom Sleeve Cover , Silicone Bottle Sleeve ,Silicone Hand Sanitizer Holder,Silicone Sanitizer Bracelet,Silicone Bottle Holder manufacturers from China.
Our Factory Advantages:
1.Mold workshop and 2D and 3D engineer department
2.Solid siliccone compression machine and liquid silicone injection machine
3.Disney and Sedex 4P audit factory
4.ISO 9001,IATF16949,Raw material of FDA LFGB MSDS Certificates
Look forward to your cooperation!
Silicone Hand Sanitizer Holder,Silicone Hand Sanitizer Sleeve,Sanitizer Holder With Travel Bottle,Cute Cartoon Silicone Sleeve
Shenzhen Yindingsheng Technology Co., Ltd , https://www.oemsiliconeyds.com