Continuous Frequency Sweeping Alarm Circuit for Ambulance or Police Siren

Assembled Alarm Circuit

Sweeping out the frequency of an alarm that produce continuous spectrum has some benefits. First, it improve the alertness of the signal since people normally get alerted on the perception of “change”, and it works for almost any signal (audio, visual, thermal, etc.). Second, sweeping the frequency makes sure thatĀ  all people will get their sensitive spectrum covered. With these […]

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Classic Alarm Circuit Employs Class-C Aamplifier for More Power

Picture of Assembled Alarm Circuit

Basic alarm with small transistors presented in our previous alarm circuit article is usually enough for toys, but we might need more power if we wanna use it for automotive or industrial application. If you usually see class-c amplifier application in radio frequency circuit, then we will show you how it can be applied in audio circuit as well. From […]

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Classic Two Transistor Alarm

Assemble Alarm Circuit

A very simple alarm circuit can be built using two transistors and several passive components. We don’t know who is the inventor of this circuit, but it usually presented in many old electronics books, so let’s call it “classic”. This simple circuit implement complete function of an alarm, which is nothing more than an oscillatorĀ  with high enough power to […]

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