555 Siren Alarm | Electronic Project Circuits

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Police sirens sound with ic 555

Many a person will might excited with siren sound the all that ever hear. Because we will hear when there is an accident emergency event. But ever suspect that how is those sound can happen ?
The work of the circuit IC1 which build be astable multi vibrator circuit. Will signal frequency low origin comes out the way pin 3 have about 1 Hz by frequency value that s were fixed by the value , R1, R2, C1 signal the frequency will have that to come out pin 3 ways which built get along well with 5 of IC2 change R5 . By the frequency from IC1 will touch total up with the frequency at IC2 establish will valuable about 440 Hz – 550 Hz the frequency had that to sent come out pin 3 ways. Which be take gush up of IC2 the connection goes to get along well with B of Q1 for enlarge the trend comes to sing bail make the sound of the circuit that comes out resemble the sound of police siren.

Be the first to comment - What do you think? Posted by admin - July 24, 2010 at 4:02 am

Categories: Alarm systems Tags: 555 siren alarm

Two sirens sound with ic 555

Operation of the circuit. Circuit is divided into three parts: low frequency production. The manufacturing high frequency and extension of production low frequency is obtained from IC1 connected to astable multi vibrator circuit frequency is set by R1, C2 frequencies that are coming out of pin 3 is about 1 Hz through R2 to be good 5. of IC2, a division produce high-frequency input at Pin 5 will tone the origin of oscillator IC2 is the ripple of voltage from the output of IC1 frequency of IC2 is being set by R3, C3, which, if C3 value. will be very low tone if C3 is less treble The output will have to stand out in three legs of IC2 to stimulate B of Q1 to amplify signals that drive speakers.

Be the first to comment - What do you think? Posted by admin - June 12, 2010 at 7:07 am

Categories: Alarm systems Tags: 555 siren alarm, Two Tone alarm

Sweeping Output Frequency Siren

This circuit is a variation of the “Two Tone” siren that is a standard for the LM555 timer. The circuit allows the output frequency of the ‘B’ timer to ‘sweep’ between two frequencies rather than switching abruptly between two fixed frequencies. [...]
Read More Source: http://home.cogeco.ca/~rpaisley4/LM555.html