Sonalerts and Screamers

[last updated: 2020-10-15]
see also: piezo alarms
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• Sonalert is a brand name of a line of buzzer/annunciators. I'm using the term generically.
• Screamers are what I'm calling the little annunciators that put out high db, high frequency warbling sound, and are sold and used as personal "rape" alarms - $2 - $3 on eBay. They draw about 110ma at 5v




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• SparkFun: 13940
  This is a Challenge Electronics CE-C75.
  
  

  piezo Alarm (SparkFun: 13940)

  This alarm produces a 3KHz continuous tone at up to 100dB (ie. fairly loud) and has an input range of 3V to 18V.
  +V terminal is at the flat
  It draws about 14ma
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• SFM-27 Intermittent beep:


SFM-27 piezo Alarm
• ~ 11ma peak
• eBay: 2Pcs DC 3-24V SFM-27 Continous Beep Piezo Active Electronic Buzzer
  Amazon: uxcell SFM-27 DC 3-24V Intermittent Sound Electronic Alarm Speaker Buzzer
  AliExpress: SFM-27 DC 3-24V 90DB Intermittent Beep Alarm Electronic Buzzer Sounder
  Banggood: Black/White High Decibel Alarm SFM-27 DC6-24V Continuous Sounder Buzzer Speaker
  SKU119428
• youTube to make continuous tone instead of intermittent beep:
  (link to:) youTube

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