摘要 |
<p>An electronic control device for providing control signals having direction and magnitude represented by electrical output signals operates by sensing relative changes in capacitance. The device utilises circuitry requiring only a few volts excitation at a suitable frequency. In operation of the device, a finger touch unbalances the equilibrium between a pair of capacitance electrodes C1, C2 which by means of the circuitry selectively produces signals representative of magnitude and direction, and whose value is proportional to the degree of imbalance, and which signals are used for vector control purposes. The electrodes C1, C2 are positioned in recessed slots 20, 22 in a casing 12, which slots are accessible by fingers. The capacitance electrodes C1, C2 are protected by a dielectric layer 24.</p> |