Clap Switch 5lx32

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ABSTRACT This paper presents the design of a clap activated switch device that will serve well in different phono-controlled applications, providing inexpensive key and at the same time free from false triggering. This involves the design of various stages consisting of the pickup transducer, low frequency, audio low power and low noise amplifier, timer, bistable multivibrator and switches. It also consists of special network components to prevent false triggering and ensure desired performance objectives. A decade counter IC serves the bistable function instead of flip-flop. c c c c c c c c c

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=REFACE c The primary purpose of switch is to provide means for connecting two or more terminals in order to permit the flow of current across them, so as to allow for interaction between electrical components. The motivating force behind this design is based on the desire to alleviate the problem faced by the aged and physically challenged persons in trying to control some household appliances. It also takes into considerations the illiterates that may have problems operating some ³complex´ hand-held Remote Control Units (RCUs). Therefore this paper provides an introductory study on the basic principles involved in utilizing acoustic energy to control switching process. This is achieved by converting the energy generated by the ³handclap´ into electrical pulse, which is in turn used to drive an electronic circuitry that includes a relay, which in turn switches ON/OFF any appliance connected through it to the main. c c c c c

c c c c c | || c INTRODUCTION BLOCK DIAGRAM BLOCK DIAGRAM EX=LANATION CIRCUIT DIAGRAM COM=ONENT STUDY CIRCUIT DESCRI=TION =RINTED CIRCUIT BOARD(=CB) LAYOUT COM=ONENTS REQUIRED A==LICATIONS CONCLUSION = OTOS OF T E FINAL =RODUCT A==ENDIX- DATA S EET

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The operation of the circuit is simple. Clap and the lamp turns on. Clap again and it turns off. The condenser microphone picks up the sound of your claps, coughs, and the sound of that book knocked off the table. It produces a small electrical signal which is amplified by the succeeding transistor stage. Two transistors cross connected as a bistable multivibrator change state at each signal. One of these transistors drives a heavier transistor which controls a lamp. This circuit can switch on and off a light, a fan or a radio etc by the sound of a clap. This working of this circuit is based on amplifying nature of the transistor, switching nature of transistor , relay as an electronic switch .



| IN=UT TRANSDUCER

The sound of your claps is picked up using a condenser microphone. This microphone has a stage of amplification built in. The

power for this built in amplifier is supplied by connecting a resistor to a positive source of voltage, and the changes in current get reflected as changes in voltage across this resistor according to the familiar relation V = I*R. A larger resistor will give you a larger voltage, but then, the current into the device gets reduced which brings down the gain. The value of 5600 ohms (usually abbreviated to 5.6K, and written down in schematics as 5K6) seems to work all right. AM=LIFIER A transistor stage, biased near cut-off amplifies the signal from the microphone. The output of the microphone is coupled to the base of the transistor using an electrolytic capacitor (note: using a better capacitor here will not work). The first time the

microphone output goes positive, however, (because somebody clapped) this change gets coupled to the base entirely due to the action of the capacitor. This causes the current through the transistor to increase, and this increase in current causes the voltage at the collector, which was sitting near the supply voltage, to fall to nearly zero. This is not a high fidelity audio amplifier. Its function is to produce no output for small sounds and large output for (slightly) bigger sounds, so the customary biasing network can be omitted. BISTABLE MULTIVIBRATOR STAGE

Two cross connected transistors in a bistable multivibrator arrangement make up a circuit that re. You can set it to one of two possible states, and it will stay in that state until the end of time. When one transistor conducts, its collector is near ground, and a resistor from this collector feeds the base of the other. Since this resistor sees ground at the collector end the base at the other end receives no current, so that transistor is off. Since this transistor is off, its collector is near supply potential and a resistor connects from this to the base of the other transistor. Since this resistor sees voltage, it supplies the base with current, ensuring that the transistor remains on. Thus this state is stable. By symmetry, the other state is, too. C ANGING STATE On a clap, the state of the bistable changes. The output of the amplifier is converted to a sharp pulse by ing it through a (relatively) low valued capacitor. This is connected through "steering" diodes to the base of the transistor which is conducting. This transistor stops conducting, and the other transistor was not conducting anyway. So at a clap, both transistors become off.

Then, those two capacitors across the base resistors come into action. The capacitor connecting to the base of the transistor which was ON has voltage across it. The capacitor connecting to the base of the transistor which was OFF has no voltage across it. OUT=UT STAGE An incandescent lamp of 60watt is connected in the output stage through a relay.

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CA=ACITOR The capacitor plays a crucial role in electronics -- it stores electrons for when they're needed most. Capacitors consist of two conducting plates placed near each other. Inside the capacitor, the terminals connect to two metal plates separated by a dielectric. The dielectric can be air, paper, plastic or anything else that does not conduct electricity and keeps the plates from touching each other..

They can store electric charge for later discharge. Direct current through a capacitor will charge the capacitor for a short time, and then stop flowing. Alternating current, because of the changing electric fields it generates, can ³flow´ across a capacitor. BATTERY If you look at any battery, you'll notice that it has two terminals. One terminal is marked (+), or positive, while the other is marked (-), or negative. In an normal flashlight batteries, the ends of the battery are the terminals. In a large car battery, there are two heavy lead posts that act as the terminals. Electrons collect on the negative terminal of the battery. If you connect a wire between the negative and positive terminals, the electrons will flow from the negative to the positive terminal as fast as they can (and wear out the battery very quickly -- this also tends to be dangerous, especially with large batteries, so it is not something you want to be doing). Normally, you connect some type of load to the battery using the wire. Inside the battery itself, a chemical reaction produces the electrons. The speed of electron production by this chemical reaction (the battery's internal resistance) controls how many electrons can flow between the terminals. Electrons flow from the battery into a wire, and must travel from the negative to the positive terminal for the chemical

reaction to take place. That is why a battery can sit on a shelf for a year and still have plenty of power unless electrons are flowing from the negative to the positive terminal, the chemical reaction does not take place. Once you connect a wire, the reaction starts.

CONDENSER MICRO= ONES A condenser microphone is essentially a capacitor, with one plate of the capacitor moving in response to sound waves. RESISTOR A resistor is a two-terminal electrical or electronic component that resists an electric current by producing a voltage drop between its terminals in accordance with Ohm's law: R=V/I The electrical resistance is equal to the voltage drop across the resistor divided by the current through the resistor. Resistors are used as part of electrical networks and electronic circuits. DIODE: An electronic device that restricts current flow chiefly to one direction. An electron tube having a cathode and an anode. A two-terminal semiconductor device used chiefly as a rectifier. LEDs and diodes used in the circuit cost 10 rupees. TRANSISTOR: A 'transistor' is a semiconductor device, commonly used as an amplifier or an electrically controlled switch. The transistor is the fundamental building block of the circuitry in computers,cellular phones, and all other modern electronic devices. Because of its fast response and accuracy, the transistor is used in a wide variety of digital and analog functions, including amplification, switching, voltage, signal modulation, and oscillators. Transistors may be packaged individually or as part of an integrated circuit, some with over a billion transistors in a very small area. BC 549 and BC 548 transistors are used in this circuit.

IC555 555 Timer IC is an integrated circuit (chip) implementing a variety of timer and multivibrator applications. The IC was designed by

ans R.

Camenzind in 1970 and brought to market in 1971 by Signetics (later acquired by =hilips). IC4017 The 4000 series (originally: CD4000 series, but now includes EF4000 series, etc.) is a family of industry standard integrated circuitswhich implement a variety of logic functions using Complementary Metal±Oxide±Semiconductor technology. They were introduced byRCA as p p in 1968, as a lower power and more versatile alternative to the 7400 series of TTL logic chips. RELAY: A relay is an electrical switch that opens and closes under the control of another electrical circuit. In the original form, the switch is operated by an electromagnet to open or close one or many sets of s. It was invented by Joseph enryin 1835. Because a relay is able to control an output circuit of higher power than the input circuit, it can be considered, in a broad sense, to be a form of an electrical amplifier.

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The amplified signal provides negative pulse to pin 2 of IC1 and IC2, triggering both the ICs. IC1, commonly used as a timer, is wired here as a monostable multivibrator. Trigging of IC1 causes pin 3 to go high and it remains high for a certain time period depending on the selected values of R7 and C3. This µon¶ time (T) of IC1 can be calculated using the following relationship: T=1.1R7.C3 seconds where R7 is in ohms and C3 in microfarads On first clap, output pin 3 of IC1 goes high and remains in this standby position for the preset time. Also, LED1 glows for this period. The output of IC1 provides supply voltage to IC2 at its pins 8 and 4. Now IC2 is ready to receive the triggering signal. Resistor R10 and capacitor C7 connected to pin 4 of IC2 prevent false triggering when IC1 provides the supply voltage to IC2 at first clap. On second clap, a negative pulse triggers IC2 and its output pin 3 goes high for a time period depending on R9 and C5. This provides a positive pulse at clock pin 14 of decade counter IC 4017 (IC3). Decade counter IC3 is wired here as bistable. Each pulse applied at clock pin 14 changes the output state at pin 2 (Q1) of IC3 because Q2 is connected to reset pin 15. The high output at pin 2 drives transistor T2 and also energizes relay RL1. LED2 indicates activation of relay RL1 and on/off status of the appliance. A free-wheeling diode (D1) prevents damage of T2 when relay de-energizes

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| No.c

Component Namec

Valuec

Quantityc

1c

IC1,IC2c

555c

2c

2c

IC3c

4017c

1c

3c

Diode c

IN4001c

1c

4c

Capacitorc c

c

4c

5c

Capacitorc c

c

1c

6c

Capacitorc c

c c

1c

7c

Capacitorc c

cc

1c

8c

Resistorc c

cc

2c

9c

Resistorc c

c

1c

10c

Resistorc c

c

1c

11c

Resistorc c

c

2c

12c

Resistorc c

c

3c

13c

Resistorc c

c

2c

14c

Resistorc c

c

1c

15c

Resistorc c

c

1c

16c

LED (LED 1)c

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1c

17c

LED (LED 2)c

c

1c

18c

Transistor (T1)c

c

1c

19c

Transistor (T2)c

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1c

20c

Condenser Microphonec

..c

1c

21c

Relay (RL1)c

9Vc

1c



| This circuit is very much useful to switch ON and OFF the household appliances just by clapping hand. This circuit functions on using the sound energy provided by the clap which is converted into electrical energy by condenser mic .This circuit turns on and off a light, a fan, a radio, a TV. etc using this converted electrical energy which is used to turn on relay (an electronic switch). The major advantage of a clap switch is that you can turn something (e.g. a lamp) on and off from any location in the room (e.g. while lying in bed) simply by clapping your hands. The primary application involves an elderly or mobility-impaired person. A clap switch is generally used for a light, television, radio, or similar electronic device that the person will want to turn on/off from bed. The major disadvantage is that it's generally cumbersome to have to clap one's hands to turn something on or off and it's generally seen as simpler for most use cases to use a traditional light switch.





After the successful working of the project, it can be concluded that this project is suitable to switch ON and OFF the household appliances just by clapping hand. As a team we tried our level best to bring out the best , even though this is not a very innovative project , within our limitations we think we did justice to this project.

The final product.

The circuit that makes it happen.