Many electronics circuits and projects for learning in simple ways.

555 timer audio alarm circuits

We have many ways to build the buzzer sound circuit. We used to build them with the transistors. But now we like to use the IC-555 timer more than. ?Because it easy,small amount,and cheap. We have 3 circuit example below.

555 timer audio alarm circuits

The danger beep circuit using IC-555

This is danger beep circuit. It use 555 integrated number circuits build to are a stable mutivibrator that be valuable duty cycle 5% driver loudspeaker 8ohm 0.25W sizes. By change transistor BD136 will get danger beep use make person penetrate a hole is frightened or call for the interest from a neighbor for asks for help. Because of use part a little , then have small-sized and use current just 50mA from a place turns on the power supply 9Volt only.

The danger beep circuit using IC-555

Tone Burst Generator using LM555

Friends take an interest try build Tone Burst Generator be simple is. Try this circuit like sure because useIC 7555 , highly popular again. Assure that not sure difficult press the the secretariat of the senate S1 a loudspeaker will utter to come out immediately. When liberate S1 already the sound may loud again next many second. The C2 and R4 control time drag. The C1 control the frequency.( Use the integrated circuit IC 7555 use power source a little more IC 555 very )The detail is other see in the circuit request have fun Tone Burst Generator please sir.

Tone Burst Generator using LM555

Annoying high pitch noise generator using IC-555

This is a simple high pitch noise generator circuit. It has a timer oscillator with a frequency variable from 15khz – 30khz.
The circuit can be mounted in a plastic box like I have done. The good thing about high frequency sounds is that it is very hard to find where they are coming from. Also, the noise is very annoying and irritating. The crystal speaker is the creamy coloured thing at the bottom of the photo on the left.
Annoying high pitch noise generator using IC-555


This Post Has 3 Comments

  1. Hi ElecCircuit,

    I was looking into your LM555 reference designs and found the high pitch noise generator interesting (found here:, I wanted to build the circuit above, but the diagram was not specific on how to select the appropriate audio transformer and “Crystal” speaker.

    I was wondering, do you have any additional information or a parts list/Bill of materials for the, “Annoying high pitch noise generator by 555.”

    Please email me back at [email protected]

    Thank You,

  2. Hi,Ron Vick
    Thanks for your feedback.

    You can use normal speaker and audio transformer output which can buy it general electronic store.

  3. Hello,

    These look very interesting! I am trying to build a circuit which emits a 1V high frequency audio signal (maybe 10kHz?) for about 5ms every OTHER time a pushbutton is depressed. Can a 555 be configured in this way? I am a complete beginner here, but I have been tasked with a very specific project and would greatly appreciate some help!


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