摘要 |
An improved force transducer which may, for example, be used as a joystick control for computer display control. Co-planar strain gauges are configured for response to forces applied in each of three orthogonal directions. A post and underlying ceramic substrate, the latter having the strain gauges mounted thereon, are mounted to a printed circuit board by means of a conductive epoxy or solder in a gap between the substrate and the circuit board. A retainer may be used to limit the extent of post displacement in X and Y directions to prevent damage to the assembly from forces which would otherwise exceed the physical limits thereof. In a preferred embodiment, the post and underlying substrate are implemented as a unitary ceramic body. In another embodiment, ballast or trim resistors for balancing the output of the transducer, are located under the post. In yet another embodiment the metal paths or traces which connect to the strain gauges, follow a unique arrangement to avoid crossing over each other. In still another embodiment, temperature variation effects are nullified by employing an additional strain gauge or resistor for measuring forces in the Z direction.
|