Comment on Do smoke detectors have little speakers inside them? If yes, would it be possible to hack them to play a little jingle?

Fermion@mander.xyz ⁨2⁩ ⁨days⁩ ago

• Ephera@lemmy.ml ⁨2⁩ ⁨days⁩ ago

  I would guess that the units used in smoke alarms and microwaves generally have integrated drivers that only operate at a single frequency.

  Yeah, you could more easily create a rhythm than a full melody. If you get a few devices, which beep at different frequencies each, you could do a lot more by having them beep in succession and in intervals.

  Of course, this requires that they’re roughly in tune, which may not be the case at all. 🥴

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• db2@lemmy.world ⁨2⁩ ⁨days⁩ ago

  You can if the buzzer signal is only used to trigger a secondary circuit that does what op is looking for.

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  • dddontshoot@lemmy.world ⁨2⁩ ⁨days⁩ ago

    That’s what I would do. Hook jumpers from the buzzer to the play button of an mp3 player. That way if the music system fails, the buzzer still wakes you up.

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• ageedizzle@piefed.ca ⁨2⁩ ⁨days⁩ ago

  Interesting thank you. The integrated drivers thing would make it difficult to hack but I guess its always possible to crack the smoke alarm and replace the drivers, if someone really wanted to get their hands dirty 

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• ChaoticNeutralCzech@feddit.org ⁨2⁩ ⁨days⁩ ago

  Piezo buzzers have a resonant frequency they’re strongest at. Two-pin piezo disks need driving at the desired frequency. Three-pin provide a phase-shifted feedback to the driving transistor to keep oscillating at the resonant frequency. Some include that whole circuit inside their housing so they have just 2 pins but those are for DC power, only the volume can be somewhat adjusted by changing the input voltage.

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  • Creat@discuss.tchncs.de ⁨2⁩ ⁨days⁩ ago

    The only ones I’ve ever used myself area is the DC variety. Apply power: beeeeep; stop applying power: <sound stops>

    I don’t know why idea are more commonly used in consumer electronics.

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