Two Tone Alarm with IC LM3900
Circuit Two Tone Alarm with IC LM3900
This be Two tone alarm use op-amp IC number LM3900 (Quad Amplifiers) perform produce the frequency square wave 2 level , be high frequency and low then mix the sound in the end danger beep that is appropriate it has can to link up a loudspeaker with ,using power mosfet then have better use transistor which complicated and not durable. This circuit convenients for power supply 9V to 12V sizes and 8 ohm 20watt size loudspeakers will by large-sized have a voice loud small-sized better.
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This circuit use 2 beep danger sound origins. By use the integrated circuit LM3900 just one. Which compose OP-Amp 4 group stay within the integrated circuit and have , Mosfet , give -ing the sound with 8-80 ohm small-sized loudspeakers s by use , power supply 9V sizes will arrive at 12V may ...
The circuit is see this it , sound generator warbling tone , which hear distinct in swoop down that have a voice disturb , get more than , single tone. By the transistor Tr2-TR3 assemble the circuit tone Generator , Which frequency modulated with output of TR1 which it frequency genera ...
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 p ...
This circuit uses digital CMOS IC 74HC04 used power supply 3V only. The IC perform produce the frequency about 2.8kHz and 3.3kHz work can alternate into pieces warn to follow want. These handheld piezo screamers are also known as rape alarms. They are a very loud siren. This one is particul ...
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 ...
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