12 x SOUNDTECH 15mm PASSIVE PIEZO DISKS Tone Buzzer Audio Alert Sounder SEP-1156

Description

12 pieces of Soundtech SEP-1156 Passive Piezo Disks
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This item is for Soundtech part SEP-1156, which is a 15mm diameter Piezo Disk mounted inside a small plastic enclosure designed to mount on a printed circuit board.
You can see the construction in the second picture, where I popped one open to see what was inside. Even simpler than I imagined, the piezo fits flush inside, and the small plastic disk that closes the case and has the connection pins just touches the piezo with two metal tabs bent so they are under slight tension.
PASSIVE vs ACTIVE
: This is a passive unit that requires an AC signal to make a sound. By changing the frequency, you can make sounds of different tones (or play music or other complex material). An active unit only requires a DC voltage as its sound generation circuitry is built in, but it lacks the flexibility of a passive unit.
The inside diameter of the little round enclosure measured 15mm in diameter on my electronic caliper, and that should be the outside diameter of the piezo.
The enclosure has an outside diameter of 16.9mm. The piezo material at the center of the brass disk measures roughly 9mm in diameter. The enclosures are 7.3mm high, not counting the spacing tabs on the bottom. When those are included, the height is 9.2mm.
Each piezo and enclosure weighs just a bit over 1 gram.
Condition: Excellent. These are NOS (New Old Stock), left overs from an electronic manufacturer that was active in the late 1990's/early 2000's.
The pictures show typical units from the batch yours will come from, and they will have the identical appearance. The Soundtech label shown in the last picture is on the box that the units were in.