This condition is maintained until the 20 KHz signal is received by the pin3 of the LM567. The lamp will blink as a warning signal because of the PWM signal generated by the timer, transistor will work as a switch and resistor R10 will limit the current. The timer output also is given to the lamp through a transistor. The output of the timer is enabled which can be assured by the LED (blinking) and also buzzer will beeps at determined rate given by the resistors R6, R7 and capacitor C7. At this point the pin8 of LM567 is high which will enable the LM555 timer operating in astable multivibrator mode. The resistor R1 will resists the IR senor current. When the car is driving in reverse the car battery will provide DC supply the reverse light indicator at the back of the car when this supply came to the reverse light indicator the circuit will have the power supply.7805 will regulate the DC voltage to 5V and give to the IR Sensors through the transistor with 20 KHz modulating frequency of the LM567 (TONE DETECTOR) available at Pin5.The diode D6 is used to eliminate the reverse current and wrong supply polarity.
The reverse indicator light supply is given to the 7805 regulator to give 5v to the rest of the circuit.Circuit Diagram of Car Parking Guard: Explanation: It is having a maximum frequency of 20 KHz. But it will work slowly when compared to the other transistors. The main function of this transistor is to amplify the input signal of the transistor. They will conduct to the light or electro magnetic signals. Photo Darlington Transistor: the photo darlington transistor will act as a photo detectors. IR Sensor: the main function of the IR sensor is to produce a beam for certain distance (the distance of the beam is always depends on the IR sensor, different IR sensor have different range of beam distance) if the there is any obstacle in the beam it will conduct and give signal. The 555 timer is mainly used to control the other peripherals like motors, detectors, regulators etc. LM555: is a timer which can generate a PWM signals in various width and duty cycles. The tone detector is mainly used in touch tone decoders, ultrasonic controls, frequency monitoring and control etc. At this decision making we will use tone detector. For example if a component is attached to the input of LM567 which can generate a 40 kHz signal, but we to function the following circuit when the component has reached to the 40KHz. LM567: is a tone detector which can interpret the frequency generated by the other component and give the output according to the application designed by the engineer.
The LM555 will generate the pulse which helps to buzz the buzzer so driver can understand that there is an obstacle.
The IR sensor will detect the obstacle with in 100cm, if there is any obstacle it will sense and give information to the tone detector which will enable the LM555 timer to generate a PWM for the buzzer. Our project will help the person in the driving seat and give alarm if there is any obstacle or a wall while parking or while driving in reverse. Introduction: While parking the car the driver should be more careful because he cannot see the back of the car while parking or taking reverse, if there is any obstacle and ran over it might be get damage to the car.