Project Logic
This document was uploaded by user and they confirmed that they have the permission to share it. If you are author or own the copyright of this book, please report to us by using this DMCA report form. Report DMCA
Overview
Download & View Project Logic as PDF for free.
More details
- Words: 241
- Pages: 2
Police Siren Apparatus 555 timer ICs, Resistors: • 2.2K • 2.2K • Variable resistors: Capacitors: • 0.01uF • 47uF • 0.1uF • 1uF/15V ON/OFF Switch Speaker 8ohm/0.5Watt
Objectives:Production of police siren
Procedure: 1. It makes use of two 555 timer ICs used as astable multivibrators. The frequency is controlled by the pin 5 of the IC. 2. The first IC (left) is wired to work around 1Hz. The 47uF capacitor is charged and discharged periodically and the voltage across it gradually increases and decreases periodically. 3. This varying voltage modulates the frequency of the 2nd IC. This process repeats and what you hear is the sound remarkably similar to the police siren. 4. Two presets VR1 and VR2 are provided to vary the siren period of repetition and the tone of the siren. 5. By varying VR1 you can set how fast the siren changes from high freq. to low freq. 6. VR2 sets the siren frequency. Adjust VR1 and VR2 to suit your taste.
Diagrammatical representation of the circuit
APPLICAITIONS OF THE CIRCUIT: 1. It has many applications in every daily life. 2. Emergency situations. 3. As a traffic siren.
Precautions : 1. 2. 3. 4.
ICs should be handled carefully. Bipolar capacitors should be properly placed in the circuit. Voltage supply must be in the range of 5V and 15V. Variable resistors should function properly as amplitude of siren depend on its variation. 5. Wiring should not be loose.
Objectives:Production of police siren
Procedure: 1. It makes use of two 555 timer ICs used as astable multivibrators. The frequency is controlled by the pin 5 of the IC. 2. The first IC (left) is wired to work around 1Hz. The 47uF capacitor is charged and discharged periodically and the voltage across it gradually increases and decreases periodically. 3. This varying voltage modulates the frequency of the 2nd IC. This process repeats and what you hear is the sound remarkably similar to the police siren. 4. Two presets VR1 and VR2 are provided to vary the siren period of repetition and the tone of the siren. 5. By varying VR1 you can set how fast the siren changes from high freq. to low freq. 6. VR2 sets the siren frequency. Adjust VR1 and VR2 to suit your taste.
Diagrammatical representation of the circuit
APPLICAITIONS OF THE CIRCUIT: 1. It has many applications in every daily life. 2. Emergency situations. 3. As a traffic siren.
Precautions : 1. 2. 3. 4.
ICs should be handled carefully. Bipolar capacitors should be properly placed in the circuit. Voltage supply must be in the range of 5V and 15V. Variable resistors should function properly as amplitude of siren depend on its variation. 5. Wiring should not be loose.
Related Documents
Project Logic
December 2019 10
Logic State Analyser( Project)
November 2019 33
Logic
May 2020 28
Logic
November 2019 49
Logic
November 2019 44