Transistors are like switches; they can be opened to let air flow through the white tubes, and closed to stop the air from flowing. This opening and closing is done by another airflow (red tube).
This transistor is normally closed, which means it does not let air flow through, unless the pressure on the red tube is high enough, then it opens.
The transistor has no directionality; air can flow in either direction through the white tubes.
Transistors are often used to:
- Control airflow in one circuit by air from another circuit. This can be particularly useful when building control loops: a circuit (which goes through the white tubes) can only perform a certain action when the airflow is turned on by pressure on the red tube.
How does it work?
The tube inside the transistor is initially kinked, so no air can flow through. As the pressure builds up inside the transistor from the airflow through the gate tube, the center volume that contains the small tube inflates. As the volume inflates, the tube is pulled apart from both sides, as it is connected to the two membranes on either side, and eventually it unkinks. Once it unkinks, the tube opens and air can flow through. When pressure is released from the gate tube, the volume can deflate again, and the tube will re-kink, thus stopping air from flowing through.
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