These are several medium-wave ceramic resonator filters, with center frequencies of 455kHz and 465kHz. Now, we're going to tear down one of them and delve deeper into its internal structure. We're doing this for no other reason than sheer curiosity.
Teardown Revealed
After carefully peeling back one side of the resonator with diagonal pliers, we're able to glimpse its inner workings.
Continuing our exploration, we discover a multi-layered structure within the resonator. Peeling back the plastic covering, we gain a deeper understanding, revealing the internal lead structure. Closer inspection reveals metal electrodes on both the top and bottom, and a cleverly designed double-layer structure in the center. Further disassembly reveals the resonator's three core components: three electrodes, split into two halves, on the left, and the piezoelectric ceramic in the center. This piezoelectric ceramic, with its inner and outer electrodes, forms a buffer system with the conductive rubber underneath, ensuring a smooth connection between the piezoelectric ceramic and the metal electrodes.
The piezoelectric ceramic's internal structure is intricate, indeed possessing three electrodes: two on one side and only one on the other. Conductive rubber is strategically placed on the surfaces of these two electrodes, providing excellent electrical conductivity. By connecting the two electrodes on the piezoelectric ceramic to external pins, a smooth connection with the metal electrodes is ensured, forming a stable buffer system.
The device contains three electrodes, with the center electrode on one side of the piezoelectric ceramic separated from the electrodes on the other two sides. On the other side of the piezoelectric ceramic, the two electrodes are connected to the center and edge of the piezoelectric ceramic, respectively, ensuring a stable electrical connection.
In addition to resonators with three pins, there are also devices with only two pins. Next, we will examine a two-pin resonator. Upon opening it, we find that it also consists of three parts, but unlike the piezoelectric ceramic, the corresponding electrodes are only located on the front and back surfaces. These electrodes are also connected to the piezoelectric ceramic via conductive rubber, ensuring a stable electrical connection.