摘要:
In a matrix of capacitive key cells (A1,A2,B1,B2) of the type including a contact switch (20) in series with a key cell capacitor (21), an intracell coactive loading capacitor (22) is connected between ground and the junction (23) of the contact switch (20) with the key cell capacitor (21). A matrix of key cells (A1,A2,B1,B2) so formed is self-referencing, in that the need for a separate reference capacitor to load a sense line (50) is eliminated. Instead, loading is provided intrinsically by the effect of the intracell coactive loading capacitors (22) acting through multiple key cells (A1,A2,B1,B2) connected to a sense line (50).
摘要:
In a matrix of capacitive key cells (A1,A2,B1,B2) of the type including a contact switch (20) in series with a key cell capacitor (21), an intracell coactive loading capacitor (22) is connected between ground and the junction (23) of the contact switch (20) with the key cell capacitor (21). A matrix of key cells (A1,A2,B1,B2) so formed is self-referencing, in that the need for a separate reference capacitor to load a sense line (50) is eliminated. Instead, loading is provided intrinsically by the effect of the intracell coactive loading capacitors (22) acting through multiple key cells (A1,A2,B1,B2) connected to a sense line (50).
摘要:
A tamper-resistant sign comprising a holder (l0) having a front wall (ll) spaced from a rear wall (l2) to define a sign chamber (l7) between the walls, and a sign panel (30) inserted in the sign chamber (l7). The sign panel (30) includes a retaining element (32) extending therefrom and a wall (l2) of the holder includes a recess (l8). The retaining element (32) and the recess (l8) are positioned in their respective elements so as to be aligned with one another when the sign panel (30) is fully inserted in the sign chamber (l7); the retaining element (32) is then received in the recess (l8) to restrict unauthorized removal of the sign panel (30) from the holder (l0).
摘要:
A multi-layered membrane switch (10) having a spacer layer (24) with one or more tabs (30) extending across the width of its cut out portion (28) to provide support for an upper contact supporting layer.
摘要:
A tamper-resistant sign comprising a holder (l0) having a front wall (ll) spaced from a rear wall (l2) to define a sign chamber (l7) between the walls, and a sign panel (30) inserted in the sign chamber (l7). The sign panel (30) includes a retaining element (32) extending therefrom and a wall (l2) of the holder includes a recess (l8). The retaining element (32) and the recess (l8) are positioned in their respective elements so as to be aligned with one another when the sign panel (30) is fully inserted in the sign chamber (l7); the retaining element (32) is then received in the recess (l8) to restrict unauthorized removal of the sign panel (30) from the holder (l0).