Intermittent Oscillator or Siren (CB18276E)

The basic siren configuration shown in figure 1 activates a piezoelectric transducer and can be used as an alert or warning device.

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Integrator with bias compensation (CB3939E)
We found this circuit in an old publication. The circuit can be implemented with modern equivalent...
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This circuit with transistors from a 1995 publication. The circuit is powered by a voltage taken...
Solar Oscillator (CB22262E)
This tiny photocell-powered audio oscillator was found in a book on transistors from the 1960s. The...