| 摘要 |
<p>An electronic switch (20) includes a rigid base (26), a circuit board (30) supported by the base (26) which includes an aperture (34) therethrough defined, at least in part, by spaced apart conductive terminals (36) of an electrically conductive circuit, resiliently flexible casing (28) attached to the base (26) and overlying the circuit board (30), and a plunger (32) attached to the casing and extending therefrom through the circuit board aperture (34). The plunger (32) includes a conductive portion (68) which is adjacent to the casing, and a non-conductive portion (70). The casing (28) is resiliently biased so as to normally position the plunger (32) such that the non-conductive portion thereof extends through the circuit board aperture. Depression of the casing (28), however, places the conductive portion (68) within the aperture (34) and into contact with the spaced apart conductive terminals (36) to close the electrically conductive circuit. The electronic switch (20) may be utilized in connection with, for example, a drowsiness warning device which includes a band (24) securable about a wearer's neck. The electronic switch (20) is positioned by the band below a wearer's chin for producing an alarm as the chin contacts and depresses the flexible casing (20) so as to cause the elctrically conductive circuit to close.</p> |
