摘要 |
An automotive transmission control is shown having pressure switches to sense the state of actuation of solenoid valves to provide logic signals to a microprocessor type of transmission control. The pressure switches, which sense the pressure of hydraulic fluid controlled by the solenoid valves, use a dished shaped metallic diaphragm characterized in that the pressure-deflection curve of the center of the diaphragm has minimal hysteresis and reflects that the diaphragm is relatively stiff having a positive coefficient of pressure with increasing deflection up to and above a selected pressure level at which level the center accelerates between d1 and d2. The diaphragm is loosely held on a conductor at 0 psig with the fluid pressure when it increases forcing the diaphragm into sealing and electrical engagement with the conductor.
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