| 摘要 |
PURPOSE: A circuit for measuring a high vacuum in an ion pump is provided to simplify the parts of the electronic circuit by controlling the microprocessor to play the important role related to the calculation, thereby saving the cost of the manufacturing. CONSTITUTION: A circuit for measuring a high vacuum in an ion pump includes a current limiter(16), a high speed switch(20), a current detection and log amplification unit(21), a communication interface(12), a display(25), a display interface(24), a parameter storage memory(14), a microprocessor(10), an output adjusting unit(15) and an input detector(19). The current detection and log amplification unit(21) increases the input voltage if the ion current becomes low, decreases the input voltage if the degree of vacuum is low and converts the ion current detected from the double voltage output unit(18) into a voltage signal in response to the reference value outputted from the DAC(23). The communication interface(12) is coupled to an ADC(22), a DAC(23), a program memory(11) and a PC. The display interface(24) is connected to the display(25). The microprocessor(10) is provided with a display interface(24) connected to the display(25) and a parameter storage memory(14). The output adjusting unit(15) transmits the output voltage value proportional to the degree of microprocessor(10) to the current limiter(16). And, the input detector(19) operates the current limiter(16) by detecting the over input status due to the input voltage rising of the transformer(17).
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