advantages of multi tone siren

A siren is a loud noise making device. Civil defense sirens are mounted in fixed locations and used to warn of natural disasters or attacks. Sirens are used on emergency service vehicles such as ambulances, police cars and fire trucks. There are two general types: pneumatic and electronic.

Many fire sirens (used for calling the volunteer fire fighters) serve double duty as tornado or civil defense sirens, alerting an entire community of impending danger. Most fire sirens are either mounted on the roof of a fire ....etc

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To get full information or details of Dual tone Multi Frequency DTMF please have a look on the pages

http://seminarsprojects.net/Thread-Dual-tone-Multi-Frequency-DTMF-signaling

http://seminarsprojects.net/Thread-Dual-tone-multi-frequency-signaling-DTMF?pid=79283#pid79283

if you again feel trouble on Dual tone Multi Frequency DTMF please reply in that page and ask specific fields in Dual tone Multi Frequency DTMF ....etc

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SYNOPSIS
Dual-tone Multi-Frequency (DTMF) signaling is the basis for voice communications control and is widely used worldwide in modern telephony to dial numbers and configure switchboards. It is also used in systems such as in voice mail, electronic mail and telephone banking.
The detector part of early DTMF systems consisted of analog implemented bandpass filter banks, which were tuned to the eight standard frequencies. As analog lines as well as many other analog systems were converted to digital, researchers became ....etc

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ADVANTAGES OF TOUCH SENSITIVE SIREN AND DETAILS OF CIRCUIT DIAGRAM, WORKING , REQUIREMENTS , APPLICATIONS
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four tone siren

Operation of four siren sound generator circuit using UM3561, IC1 number ready to create a sound all four sound at pin 7, 8 of IC1 to the R1, VR1 to take to control the frequency of oscillator circuit the internal IC. If the VR1 adjust less frequently and will increase, if VR1 adjusts the frequency that would cost a lot less. When the power supply is integrated into the police car sirens sound out.If the switch S1 will press space, press switch S2 sound gun will fire if the sirens sound, press switch S3 ambulance sirens will s ....etc

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i need this project description, working principle, circuit diagram and ppt ....etc

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please help me find an abstract for four tone siren and it description

please give me about abstract of four tone siren ..i have to submit this project today so help me

....etc

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ABSTRACT
This research focuses on detection of unauthorized access to residential and commercial buildings when
the residents are far away from the access gate of the house. The system is a simple and reliable touch
activated security system and uses sensor technology to revolutionize the standards of living. The system
provides a best solution to most of the problems faced by house owners in their daily life. Due to its
simple electronic components nature, it is more adaptable and cost-effective. The system is divided into
three units; t ....etc

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Touch the sensor of the alarm with your finger and it starts beeping, goes on for some time and then stops. Touching it again, and it goes again! This little and flexible circuit consists of a touch sensor and a directly coupled transistor amplifier with a small loudspeaker as the output load. Two sensor strips of metal are mounted side by side on a 1 1 cm size micasheet and connected to the input of the circuit.

How the touch alarm works

Under normal conditions no current flows through switching transistors T1 and T2 and the potential acros ....etc

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hello,
i'm a student of b.e and i'm in a need of pdf full in touch sensitive siren..w'll will be thankful to u if u respond quickly..
thanking u ....etc

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