Applications of Electronics
- 2. IIEST, SHIBPUR 2 Group 7 Group Members Devayan Basu 510614002 Rumani Chakraborty 510614011 Sayan Sen 510614046 Shamik Basak 510614063 Poushali Ray 510614064 Sandip Guhathakurta 510614065 Semester Fourth Session 2015-2016
- 3. Introduction Two types of signals: one is analog or continuous signal and the second one is digital or discrete signal. So the science or field of research in the area of engineering is termed as Analog and Digital Electronics respectively. Digital electronics are those electronics systems that use a digital signal instead of an analog signal. They are the most common representation of Boolean algebra and are the basis of all digital circuits for computers, mobile phones and numerous other consumer products. IIEST, SHIBPUR 3
- 4. IIEST, SHIBPUR The most common fundamental unit of digital electronics is the logic gate. By combining numerous logic gates (from tens to hundreds of thousands), more complex systems can be created. The complex system of digital electronics is collectively referred to as a digital circuit. It is essential to understand wide range of applications from industrial electronics to the fields of communication, from micro embedded systems to military equipment. The main (and perhaps, the most revolutionary) advantage of digital electronics is the decrease in size and the improvement in technology. 4 Introduction
- 5. IIEST, SHIBPUR 5V Regulated Supply 5 The LM7805 is a positive voltage regulator IC while the LM7905 is a negative voltage regulator IC. The circuit is using a 230V AC to 6V-0-6V step down centre tapped transformer to step down the mains voltages. Four 1N4001 diodes are used for rectification of the AC voltage to DC. 470µF electrolytic capacitors are used to filter the voltage coming from the diodes and 47µF capacitors are used for decoupling.
- 6. IIEST, SHIBPUR Audio Amplifier The LM386 is an integrated circuit containing a low voltage audio power amplifier. It is suitable for battery-powered devices such as radios, guitar amplifiers, and hobby electronics projects. The IC consists of an 8 pin dual in-line package (DIP-8) and can output 0.25 to 1 watts of power depending on the model using a 9-volt power supply. 6
- 7. IIEST, SHIBPUR 7 Audio Amplifier • To make the LM386 a more versatile amplifier, two pins (1 and 8) are provided for gain control. If a resistor is placed in series with a capacitor, the gain can be set to any value from 20 to 200. o Capacitance used: 10µF o Resistance used: 5kΩ (pre-set) • Pins 2 and 4 are grounded. • Input signal is fed through pin 3 via 10kΩ pre-set resistor, which is used as volume controller.
- 8. IIEST, SHIBPUR 8 • A 220µF electrolytic capacitor is used with pin 5 (output pin) to remove the dc components of the output signal. A filter circuit is provided with 10Ω resistor in series with 47nF ceramic capacitor to remove high frequency noises. • Power is supplied through pin 6. A 10µF capacitor is connected in parallel with a 0.1µF capacitor. These two capacitors act as decoupling capacitors. • Pin 7 is bypass, which can be left open or connected to the ground through a capacitor for stability. Audio Amplifier
- 9. IIEST, SHIBPUR Burglar Alarm and Counter 9 IC 7486 IC 4033
- 10. IIEST, SHIBPUR 10 Burglar Alarm and Counter
- 11. IIEST, SHIBPUR Alarm system circuit: • The value of resistance of L.D.R changes according to the intensity of light. So, the voltage drop across it also changes when connected across the source. • The value of the fixed resistance is so chosen that when connected with that L.D.R. & the 5V dc supply, the voltage drop across it will be almost 4.9-4.8V and 0.1- 0.2V in light and dark respectively. • One of the inputs to the XOR gate is the voltage between L.D.R. and the fixed resistance, while the other is at logic HIGH (almost 4.9V). The output of the XOR gate is fed to a buzzer, which makes sound when a burglar passes before the L.D.R. 11 Burglar Alarm and Counter To the Counter Circuit
- 12. 12IIEST, SHIBPUR Counter Circuit: • This circuit involves a 4033 IC, which is a 4-bit Johnson counter as well as a Binary to Decimal decoder, and a common cathode based 7-segment L.E.D. • The connection between 4033 IC and the 7-segment L.E.D is made as per the corresponding datasheets. • The output of the XOR gate of the alarm circuit is used as the clock pulse for the 4033 IC. In this way, this circuit records the number of burglars passing past the system. 12 Burglar Alarm and Counter From the Alarm Circuit
- 13. IIEST, SHIBPUR 13 Fire Alarm Resistor: 330kΩ, 100Ω Capacitor: 0.04 µF Transistor: BC-369 (p-n-p), BC-548 (n-p-n) Buzzer: Works for 3-27 V supply Fire Switch Bulb Battery: 9V
- 14. IIEST, SHIBPUR Fire Alarm Fire Switch Bulb: The fire switch bulb consists of two plates as shown in the picture. Initially when connected to any circuit, the switch is open as there is no connection between the two plates. Now the black solid material is sensitive to heat and if a source of fire is held near the tip of the head, the solid expands in such a way that the plate gets connected to the metal rod, thereby completing the circuit. Now if the fire is removed, then with time the solid again contracts and the circuit is again opened. 14
- 15. IIEST, SHIBPUR 15 Condenser Mic Clap Switch
- 16. IIEST, SHIBPUR 16 Clap Switch Internal Circuit of 555 IC
- 17. IIEST, SHIBPUR Clap Switch On producing sound near condenser mic, this sound will be converted into electrical energy and it will raise the potential at the Base, which will turn the Transistor ON. The potential at Point A would become low and it will trigger the 555 IC because of the low voltage (below Vcc/3) and LED will turn ON. 17 Initially the transistor is in OFF state because there is not enough (0.7V) base-emitter voltage to turn it ON. Point A is at high potential; as a result, Trigger pin 2 is also at high potential. As we know that, to trigger the 555 IC through Trigger PIN 2, the voltage of the PIN 2 must be below Vcc/3. So at this stage, LED is OFF.
- 18. IIEST, SHIBPUR After some time, LED will be turned OFF automatically because we are using 555 timer IC in Monostable Mode. LED will remain turned ON for 1.1*R1*C1 seconds. This duration can be changed by changing the value of Resistor R1 or/and Capacitor C1. Control PIN 5 of 555 Timer IC should be connected to Ground through a 0.01uF capacitor. 18 Clap Switch