Patent CZ-291151-B6 (CZ)
Title: Double-acting electrostatic transducer
Inventor: SKVOR ZDENEK PROF ING DRSC
IPC: H04R9/04
Filed: 2001-04-24
Abstract: The present invention relates to a double-acting electrostatic transducer consisting of solid stationary electrodes and electrically conducting or semiconducting prestressed diaphragm. It is formed by a base plate (1) made of insulant and provided in its corners with four identical perpendicular electrically conducting guide bolts (2, 3, 4, 5) with an assembly of at least one pair of solid, stationary flat RE electrodes (6, 15) slipped thereon. Said RE electrodes (6, 15) having the form of thin rectangular plates are provided in their corners with holes for mounting on the base plate (1) through said guide bolts (2, 3, 4, 5). Diameters of the pair of the first holes (38, 39)disposed on a first diagonal are adapted to tight mounting on the bolts (2, 3, 4, 5) and diameters of the pair of the second holes (40, 41) on the second diagonal are adapted to free passage of the bolts (2, 3, 4, 5) therethrough. Adjacent RE electrodes (6, 9, 12, and 15) disposed one above another are angularly displaced to each other by 180 degrees. The first RE electrode (6) is provided from the side bearing against the base plate (1) with a flat distance insulating pad DIV (8) and from the other side it is provided with a first DIV (7) provided with a slot. The last RE electrode (15) is provided on its upper side with a pad (16) without slot. An insulating cover plate (18) bears against the pad (16). The RE electrode (15) is further provided on its bottom side with a sixth DIV (17) having a slot that is angularly displaced by 180 degrees relative to the slot of the first DIV (7). Other pairs of the RE electrodes (9, 12) being optionally arranged between the first RE electrode (6) and the last RE electrode (15) are situated so that the  second RE electrode (9) bottom side is provided with a second DIV (11) having a slot and the upper side thereof is provided with a third DIV (10) with a slot, too. These slots are oriented identically, but they are angularly displaced by 180 degrees relative to the first DIV (7) slot. The third RE electrode (12) bottom side is provided with a fourth DIV (12) having a slot and the upper side thereof is provided with a fifth DIV (13) having also a slot that is identically oriented with that of the DIV (12). Both the slots are again angularly displaced by 180 degrees relative to that of the second and third DIV (11, 10) of the adjacent third RE electrode (12), whereby forms and thicknesses of all the DIV (7, 11, 10. 12, 13, 17) are identical and these DIV (7, 11, 10. 12, 13, 17) are provided in their corners with two diagonally arranged pairs of holes (34, 35) and (36, 37) that are identical with pairs of holes (38, 39) and (40, 41) of the RE electrodes (6, 9, 12, 15). A diaphragm (19) having the form of a long strip is passed perpendicularly to the RE electrodes (6, 9, 12, 15)  between adjacent oppositely oriented DIV  (7, 11), (10. 14), (13, 17) with the slot. One end of this diaphragm is fastened between the base plate (1) and the flat DIV (8) and the other end thereof is fastened between the pad (16) without slot and the closing insulating cover plate (18), forming thus air gaps opened alternatively on lateral sides of the assembly.