摘要 |
This invention relates to contactless buzzer unit wherein audible signals are delivered by mechanical blows of a resonator membrane by an electromagnetically driven vibrator fed from an electronic circuit with oscillating voltage pulses. A base section is provided by an electromagnetic drive unit having an iron core and a drive coil fixedly mounted on a base plate, while a casing section is provided by an audio-signaling unit including the resonator membrane, a spacer and a vibrator assembled together and attached to a case member. Both these sections are assembled together and to the case member molded with plastic material into one piece which is provided with stud posts extending from two precisely formed, precisely and mutually, precisely parallel planes formed on the case member and serving for the assembly of these sections as guiding, positioning and fixing means.
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