siren sound by using 555 timer..

[siddarth.ghaste]

Hi
I want to produce siren sound by using 555 timer.But i am getting tick-tick sound for 2Khz frequency...what should I do, i am using external drive piezo element.PLEASE HELP.

 

[Tahmid]

You can search Google for siren sound circuits based on 555.

https://www.google.com/search?hl=en....0.0.0..0.0.les;..0.0...1c.1.4.hp.unW5mfni8rQ

Here are a few:
https://creanovaengineers.blogspot.com/2012/08/factory-siren-sound-circuit-with-ic-555.html
www.eleccircuit.com/most-common-emergency-sirens-circuits/
https://www.edutek.ltd.uk/Circuit_Pages/555_Siren Generator.html

Hope this helps.
Tahmid.

 

[siddarth.ghaste]

Okay thanks..... can you tell me about Vcontrol pin of 555 timer...

 

[Tahmid]

Pin 5 is also sometimes called the CONTROL VOLTAGE pin. By applying a voltage to the CONTROL VOLTAGE input one can alter the timing characteristics of the device. In most applications, the CONTROL VOLTAGE input is not used. It is usual to connect a 10 nF capacitor between pin 5 and 0 V to prevent interference. The CONTROL VOLTAGE input can be used to build an astable with a frequency modulated output.
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http://www.talkingelectronics.com/projects/555/Page1-555.html

When the 555 timer is used in a voltage-controlled mode, the voltage-controlled operation ranges from about 1 volt below rail-voltage to 2 volts above ground (0v). Voltages can be safely applied outside these limits, but they should be confined to between 0v and rail voltage.

By applying a voltage to this pin, it is possible to vary the timing of the chip independently of the RC network. The control voltage may be varied from 45 to 90% of the Vcc in the monostable mode, making it possible to control the width of the output pulse independently of RC. When used in the astable mode, the control voltage can be varied from 1.7v to the full Vcc. Varying the voltage in the astable mode will produce a frequency modulated (FM) output.

If the control-voltage pin is not used, it should be bypassed to ground, with a 10n capacitor to prevent noise entering the chip.

Hope this helps.
Tahmid.

 

[Rog232]

Hi
I want to produce siren sound by using 555 timer.But i am getting tick-tick sound for 2Khz frequency...what should I do, i am using external drive piezo element.PLEASE HELP.

Do you want to make a single tone that is a continuous 2kHz?
I built a wailing siren circuit, but it uses two 555 timers. The tone changes up and down. You can find it at this website:
**broken link removed**

Are you wanting to use one 555 timer?

 

[siddarth.ghaste]

yes only one 555 timer.