1.ABSTRACT Sound operated switch is one of the interesting applications of 555 timer IC. The circuit uses a555 timer IC and transistor BC547 for its operation. The electrets microphone is used to provide the pulse to the 555 timer. The operation is simple. Clap and the lamp turns on. Clap again it turns off.The electrets microphone picks up the sound of your claps, coughs, and the sound of that knocked off the table. It produces a small electrical signal which is amplified by the succeeding transistor stage.Two transistor cross connected as a bistable multivibrator change state at each signal. One of thesetransistors drives a heavier transistor which controls a lamp.The transistor type is not critical and any n-p-n silicon transistors can be used. 2. INTRODUCTION Clap switch is an beginners project done using 555 timer IC. Its application is interesting thatwe can switch on an off by just clapping the hands. Simply by lying on the bed even we can switch on and off the light. The circuit which is provided in this report is the most simple andeconomical circuit for a clap switch. Since it uses a simple condenser mike to produce the pulsesignal more voltage is not necessary. It can be used for controlling ornamental lightning circuit COMPONENTS USED MICROPHONE: Function of microphone :it is a transducer which convert the energy from one form to another form . it convert sound energy to electrical energy Types of microphones microphones were not created equal. Microphones fall into two overarching categories, dynamic and condenser microphones. Here's a look at the difference between dynamic and condenser mics to help you choose the right type of microphone for your own needs. 1. Technology - Dynamic and condenser mics are fundamentally different in the way that they receive and process sound. Dynamic mics operate by induction, while condenser microphones operate by conduction. We won't get too into the specifics, but it is important to know that condenser microphones require an electrical signal to polarize the film of the mic and record a sound, which makes them exceptionally receptive but means that they either need to have a battery or a source of power. This source of power, commonly known as "phantom power", is provided by a mixer, PA, or recording hardware. Dynamic microphones don't need this source of power, but no damage will be caused by running the phantom power through them, although a hum may be generated. It's important to wait until either mic type is plugged in to turn on phantom power--NEVER turn on phantom power before plugging a microphone in. A condenser microphone has a quicker response to transients, meaning that most condenser mics are more sensitive than dynamic mics. However, dynamic microphones can usually take quite a bit more damage before breaking. Some dynamic mics, like the Shure SM57, are legendary for their ability to take a fall. 2. Cost - Dynamic microphones are typically less expensive than condenser microphones, since they're less complex technically. Decent dynamic microphones can be had for as little as $100, while good condenser microphones are generally $300 and up. The different applications of the mics contributes heavily to their cost as well, however; the relatively high popularity of dynamic microphones drives their cost down. 3. Application - Condenser microphones are most often used for recording. There are a great array of condenser mics out there, and their application is often specific to the instrument that they were designed to mic; there are extremely expensive condenser mics designed for certain types of vocals, for instance, as well as guitar amps, orchestras, and pretty much anything else. Dynamic microphones can be used for recording as well, though usually they're used to mic instruments with fairly flat responses (drum mics, for instance, are often dynamic). Most live microphones are dynamic mics, because of their relative hardiness and inexpensiveness. Do you have any questions about dynamic or condenser microphones? Post in our comments section below. When selecting microphones to use both live and in your home studio, you'll commonly come across two different types of microphones, dynamic and condenser. Let's look at both of these microphone types, and what their advantages and disadvantages are. Condenser Microphones Condenser microphones are the most common types of microphones you'll find in studios. They have a much greater frequency response and transient response - which is the ability to reproduce the "speed" of an instrument or voice. They also generally have a louder output, but are much more sensitive to loud sounds. Condenser microphones are generally much more expensive than dynamic microphones, but keep in mind, many cheap condensers exist. The problem is that most of these mics are coming from a couple factories in China, and all sound the same -- very brittle and with little low end. They require the use of a power supply, generally 48 volt "phantom power", and that's supplied very easily by most mixing boards or external power supplies (look for a switch that says "P 48" or "48V" on the channel strip or on the back of the mixer.) Condenser microphones are generally used only in studios because of their sensitivity to loud sounds and the fact that they're quite a bit more fragile than their dynamic counterparts. That being said, you'll find them onstage at live music venues for use as drum overheads or for use in orchestral or choral sound reinforcement. With condenser microphones, you'll find two different types: small diaphragm, and large diaphragm. Large Diaphragm Microphones - Large diaphragm microphones (LDMs) are generally the choice for studio vocals, and any instrument recording where a more "deep" sound is desired. A large diaphragm microphone generally warms up the sound of what it's recording, which also leads to the myth that most LDMs reproduce low frequencies better than small diaphragm mics; this isn't true, in fact, small diaphragm mics are much better at reproducing everything evenly, including bass. You'll want a pop screen if using a condenser microphone for vocals; they're so sensitive to transient noises that the "P" and "SH" sounds you make will cause distortion. Small Diaphragm Microphones - Small diaphragm microphones (SDMs) are generally the best choice where you want a solid, wide frequency response and the best transient response, which as we mentioned before, is the ability for your microphone to reproduce fast sounds, such as stringed instruments. SDMs are also the preferred choice for concert taping. Good suggestions for condenser microphones include the Oktava MC012 ($99), RODE NT1 ($199), and AKG C414B ($700) Dynamic Microphones Compared to condenser microphones, dynamic microphones are much more rugged. They're also especially resistant to moisture and other forms of abuse, which makes them the perfect choice onstage. Dynamic microphones like the Shure SM57 and Shure SM58 are legendary for not only their good sound quality, but the amount of abuse they can withstand. Any good rock club probably has at least 5 of each of these microphones in various states of aesthetic ruin; however, they still turn on and more than likely sound just as they did the day they came out of the package. Dynamic microphones don't require their own power supply like condenser microphones. Their sound quality is generally not as accurate, however. Most dynamic microphones have a limited frequency response, which makes them well-suited, along with their ability to withstand high sound pressure levels, for loud guitar amps, live vocals, and drums. That being said, there's a few companies right now producing "boutique" dynamic microphones -- some with characteristics similar to that of a condenser with the sustainability of a dynamic. Good dynamic microphones include the Shure SM57 ($99), Sennheiser E602 ($100), and the Shure SM58 ($109). Selecting Between The Two Let's take a look at what you might be doing, and then we'll suggest a microphone for your use. Recording Vocals At Home - You'll want a large-diaphragm condenser microphone if you have phantom power; if not, you might want to consider a large-diaphragm dynamic microphone like the Shure SM7B ($350). If you're on a budget, you won't get much better than a Shure SM58. Recording Acoustic Guitar - You'll want a good small-diaphragm condenser microphone. A good choice is the Oktava MC012 ($99), Marshall MXL 603S ($99), or, more expensively, the Neumann KM184 ($730). Recording Cello/Upright Bass - You'll want a large-diaphragm condenser microphone. This is because, while the strings resonate quickly, the slower transient response of the large-diaphragm microphone will lend to better low frequency reproduction on these instruments. Concert Taping - You'll want a pair of small-diaphragm condenser microphones for stereo recording. The small diaphragm allows for faster and more accurate transient replication, and better low end reproduction. Drums - Here, you'll want a combination of dynamic and condenser microphones. You need a dynamic mic on the drums themselves - Shure Beta 98 (condensers) are great on toms, and Shure Beta 57 or SM57, along with the Heil PR20, sound great on snare, Heil PR40 and Shure Beta 52 are great on kick. Then for overhead mics and cymbals, you'll want small diaphragm condenser microphones, since they give you the best frequency and transient response. However, some dynamic microphones -- such as the Heil PR series and Shure SM57 -- can be interchanged for condensers with great results. Sound is an amazing thing. All of the different noises we hearare caused by minute pressure differences in the air around us. What's amazing about it is that the air transmits those pressure changes so well -- and so accurately -- over relatively long distances.