| 摘要 |
A method and apparatus for stabilizing an initial gas flow in a soft start enabled mass flow controller, the method including opening a source gas inlet valve positioned upstream from the mass flow controller, allowing a source gas to flow to a flow control valve in the mass flow controller, and opening the flow control valve in the mass flow controller once the source gas has reached the flow control valve. The apparatus includes a soft start activation device in communication with a soft start capable mass flow controller. The soft start activation device including a timing circuit in communication with a common terminal and a negative voltage terminal of the mass flow controller, and a variable impedance timing control circuit in communication with the timing circuit. The circuit further includes a timing circuit activation relay in communication with a trigger input of the timing circuit, and a soft start activation relay in communication with an output of the timing circuit and a soft start input of the mass flow controller.
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