11-05-2012, 01:22 PM
NOISE ALARM
[attachment=21878]
ABSTRACT:
The paper presents the design, construction and testing of a simple sound activated burglar alarm. The principle of operation of this burglar alarm is simple. When the intensity of sound exceeds certain intensity, the alarm is triggered and the siren begins to operate. The speaker beeps and the flasher (light) flashes. These actions thus alert the owner of the residence and/or security personnel of the presence of an intruder.
INTRODUCTION:
Burglar alarms systems are increasingly being used in private homes, offices, stores and other businesses. They have become standard equipments especially in stores, warehouses etc. The system is also suitable for use in jewelry stores, artifacts in museums and for safe guarding drawings, paintings and sculpture in art galleries and also to detect unauthorized access.
Alarms as the name implies are used to alert in the event of any situation that is a threat. There are several kinds of alarms [10]. Some of them include fire alarms, burglar alarms, indicator alarms, heat and smoke detectors, etc.
The approach used in this work is the modular approach where the overall design was first broken into functional block diagrams, where each block represents a section of the circuit that carries out a specific function. The functional block diagram of Figure 1 also shows the interconnection between these blocks. Each section of the block is analyzed below.
ANALYSIS AND DESIGN:
A 600Ω unidirectional moving coil microphone was used. The moving coil microphone can be used with considerable lengths of cable without the need for amplifiers close to the microphone mouthpiece [3, 4].
The amplifier stage was built around an LM386 CMOS operational amplifier [2, 6]. The circuit arrangement is such that it can amplify an input signal up to 200 times its original value. Figure 2 shows the circuit diagram to illustrate the circuit.
The basic function of the amplifier stage is to amplify the input signal from the microphone to up to 200 times its original value and pass it on to the latch section of the burglar alarm circuit for further processing. The latch stage basically built around the CD4013B CMOS dual D-type flip-flop [1, 7]. The CD4013B dual D-type flip-flop is a monolithic complementary MOS (CMOS) integrated circuit constructed with N- and P-channel enhancement mode transistors. Each flip-flop has independent data, set, reset, and clock input sand “Q” and “Q” outputs. These devices can be used for shift register applications, and by connecting “Q” output to the data input, for counter and toggle applications. The logic level present at the “D” input is transferred to the output during the positive-going transition of the clock pulse. Setting or resetting is independent of the clock and is accomplished by a high level on the set or reset line respectively.
[attachment=21878]
ABSTRACT:
The paper presents the design, construction and testing of a simple sound activated burglar alarm. The principle of operation of this burglar alarm is simple. When the intensity of sound exceeds certain intensity, the alarm is triggered and the siren begins to operate. The speaker beeps and the flasher (light) flashes. These actions thus alert the owner of the residence and/or security personnel of the presence of an intruder.
INTRODUCTION:
Burglar alarms systems are increasingly being used in private homes, offices, stores and other businesses. They have become standard equipments especially in stores, warehouses etc. The system is also suitable for use in jewelry stores, artifacts in museums and for safe guarding drawings, paintings and sculpture in art galleries and also to detect unauthorized access.
Alarms as the name implies are used to alert in the event of any situation that is a threat. There are several kinds of alarms [10]. Some of them include fire alarms, burglar alarms, indicator alarms, heat and smoke detectors, etc.
The approach used in this work is the modular approach where the overall design was first broken into functional block diagrams, where each block represents a section of the circuit that carries out a specific function. The functional block diagram of Figure 1 also shows the interconnection between these blocks. Each section of the block is analyzed below.
ANALYSIS AND DESIGN:
A 600Ω unidirectional moving coil microphone was used. The moving coil microphone can be used with considerable lengths of cable without the need for amplifiers close to the microphone mouthpiece [3, 4].
The amplifier stage was built around an LM386 CMOS operational amplifier [2, 6]. The circuit arrangement is such that it can amplify an input signal up to 200 times its original value. Figure 2 shows the circuit diagram to illustrate the circuit.
The basic function of the amplifier stage is to amplify the input signal from the microphone to up to 200 times its original value and pass it on to the latch section of the burglar alarm circuit for further processing. The latch stage basically built around the CD4013B CMOS dual D-type flip-flop [1, 7]. The CD4013B dual D-type flip-flop is a monolithic complementary MOS (CMOS) integrated circuit constructed with N- and P-channel enhancement mode transistors. Each flip-flop has independent data, set, reset, and clock input sand “Q” and “Q” outputs. These devices can be used for shift register applications, and by connecting “Q” output to the data input, for counter and toggle applications. The logic level present at the “D” input is transferred to the output during the positive-going transition of the clock pulse. Setting or resetting is independent of the clock and is accomplished by a high level on the set or reset line respectively.