Design Of Vacuum Valve Automatic Detecting System Based On STC89C58RD

Vacuum valves are widely used in oil, gas, air-conditioning and exhaust gas recycling system of the automobile. At present, there is a great demand of Vacuum valves, but getting them almost relies on importing from abroad. So, some excellent domestic manufacturers begin to develop vacuum valves by themselves in order to avoid being a passive position in supply cycle and price. The foreign Vacuum valves sales testing system nearly doesn't sell abroad, and the domestics are almost detected by manual, resulting in a very low detection accuracy and low efficiency. To make vacuum valves Localization and even export to foreign countries, there is a need to providing a vacuum valve test data to determine the eligibility of the vacuum valves, for which we have independently developed a vacuum valve automatic detection system. This system can detect the vacuum valve performance parameters such as the short circuit, open circuit conditions, the release and pick time of the voltage, vacuum suppression and release time, the leakage of the valve. The whole system includes the power subsystem, detection subsystem, the host computer communication interface, vacuum barrel and so on. The power subsystem and detection subsystem are designed respectively by an independent microcontroller STC89C58RD to prevent interference between the subsystems and improve the reliability of the overall system.The power of the vacuum valves is provided by the power subsystem, the triangular wave is generated by the AD9834, the frequency of the triangular wave is adjustable; the outputs voltage of the AD7541 are used to control the duty cycle and the voltage drop across the regulator, realizing the PWM power which has the adjustable frequency, duty cycle and voltage; the PWM power parameters can be set through the keyboard, displayed by LCD, and it can also be set by PC; the commonly power parameters can be stored by AT24C02. The detection subsystem microcontroller selects the signal acquisition channels by the command of the PC, collects the data, and then sends the data to the PC. The vacuum barrel provides the negative pressure to vacuum valve, maintain the pressure of the vacuum drum to the set range by pressure sensors, vacuum pumps, relays and so on. The PC communication interface improves the testing environment and detecting precision, displays directly the parameters and detection results.At present, the power subsystem has been put into use, providing power for various solenoid valve and vacuum valve, the performance is very good. This vacuum valve automatic detection system has been tested completely, through the long running experiments, it has been proved that the detection system has stable performance and high detection accuracy. At the same time, this system has created significant economic benefits for the companies. This system has applications for invention patent, patent number: 201010200800.X.