TREE

Detecting Sound Students often want to use ‘sound’ as an input within electronic projects. Unfortunately sound is not as easy to use as light and temperature, as there is not an instant ‘single component’ solution, as is the case with, for example, an LDR for light or a thermistor for temperature. The main problems with detecting sound are: 1) electret microphone inserts are low cost, but only produce a very small signal, which requires amplification 2) the background noise level can vary considerably, and so some form of calibration is required 3) some noises, such as a hand-clap, are very quick and so can be ‘missed’ with some electronic circuits (e.g. when using a microcontroller) Fortunately these problems can all be overcome at low-cost, by using an electret microphone with three common transistors. The circuit shown in Figure 1 will produce an analogue signal between 0 and 3V that can be detected, for instance, with the analogue input pin of a PIC microcontroller (e.g. 16F876). T...

This inexpensive, fully transistorised switch is very sensitive to sound signals and turns on a lamp when you clap within 1.5 metres of the switch. One of its interesting applications is in discotheques, where lights could be turned on or off in sync with the music beats or clapping. Sound-Operated Switch for Lamps Circuit Diagram The condenser microphone senses the sound and converts it into electrical variations. The electrical signals are amplified by the two-stage direct-coupled (DC) amplifier formed by transistors T1 and T2 and fed to the switching circuit. The switching circuit comprises transistors T3, T4 and T5, which conduct only when the circuit senses sound signals. Transistor T5 supplies sufficient gate voltage to the triac to drive the 230V lamp. The regulated 12V DC power supply for the circuit is derived from AC mains by using resistor R14, diode D1 and zener diode ZD1. The circuit can be assembled on any general-purpose PCB. Soursed By: EFY: Author Pradeep G.

One of the biggest decisions that people need to make when deciding on an auto sound system is the decision of whether or not have the system professionally installed. On the one hand, it will add a pretty hefty fee to the bottom line but you just might find that the fee is well worth the expense you'd have to pay to fix any mistakes you might make along the way. The truth of the matter is that installing an auto sound system is not an easy task and requires no small degree of skill and concentration. I'm not sure about you but I'm in short supply of both when it comes to technical matters such as this and would much rather not risk my car, which will cost a lot more to repair if I make a mistake than the couple of hundred dollars that professional installation might require. When it comes down to it there are many benefits to having your sound system installed by professionals. Below you will find a few of these benefits. 1) Sound systems are huge investments. Most automob...

When you look at auto sound systems it is important to pay close attention to the speakers on the system you are considering. You will find that there are all kinds of components, pieces, and parts that go along with a proper sound system in the world of today's music systems. You need to pay special attention to every single detail along the way of choosing the system that will meet your needs, your budget, and your lifestyle with the most bells and whistles to spare. Some things that are important to remember about selecting proper speakers is that bigger isn't always better. As a matter of fact, bigger speakers are often quite inferior no matter how that might have been different in the past. As technology improves, better things are coming in much smaller packages. You do not have to have a huge set of amplifiers in order to receive not only good quality but also really big sound. I hope I can honestly say that the days of having to remove the backseat of your car in order ...

IC MSP 34X0G is a single chip that can process voice signals to all TV standard International, and very good for the digital NICAM stereo. In the IC has several advantages, namely: Communication using the I2C bus control Selection of a voice signal automatically (mono / stereo / bilingual) Loudspeaker / headphones are equipped with volume control, bass, treble, loudness and balance Loudspeaker outputs are equipped with MDB (Micronas Dynamic Bass) AVC: Automatic Volume Correction Equipped with Sub woofer output Have facilities 5-Band graphic equalizer for loudspeaker Equipped spatial effect for loudspeaker Equipped with a matrix of voters in / out Has a SCART 4 stereo inputs, one mono input and 2 stereo SCART output Block diagram of circuit in the IC MSP34X0G

Here is very simple and easy build a sound operated switch electronic circuit project. A sound operated switch with a relay driver. Simple Sound Operated Switch Circuit Diagram: Notes: This sensitive sound operated switch can be used with a dynamic microphone insert as above, or be used with an electret (ECM) microphone. If an ECM is used then R1 (shown dotted) will need to be included. A suitable value would be between 2.2k and 10kohms. The two BC109C transistors form an audio preamp, the gain of which is controlled by the 10k preset. The output is further amplified by a BC182B transistor. To prevent instability the preamp is decoupled with a 100u capacitor and 1k resistor. The audio voltage at the collector of the BC182B is rectified by the two 1N4148 diodes and 4.7u capacitor. This dc voltage will directly drive the BC212B transistor and operate the relay and LED. It should be noted that this circuit does not "latch". The relay and LED operate momentarily in response to a...

While living in rent or in hostel the problem like stealing is often in absent time. Here is the circuit of simple and inexpensive sound – operated light to overcome this type of problem which can turn on the light when someone claps, or tries to open your door or even inserts a key in the door lock. The switching of light is alternately i.e. light on by one sound pulse and off by another. It is also called clap operated light or clap switch. The entire circuit of sound operated light is designed and builds around an operational amplifier IC (IC 1 ) and JK flip-flop IC (IC 2 ). The sound coming from outside is senses by microphone and converts it to corresponding electrical signal where sensitivity of sound is controlled by potentiometer VR 1 . The high value of reference voltage is given to pin 3 of IC 1 in order to change the output voltage from pin 6. Here IC 2 (JK flip-flop) is wired as a toggle flip-flop and its output is connected to relay driver transistor T 1 thr...

When it comes to auto sound systems, one question seems to be repeated often-is bigger better? The honest answer to that is not by a long shot. There are many excellent quality sound systems that will not require the backseat and your first-born in order to enjoy wonderful quality of sound and music as you drive along on your daily commute. One thing that is important to remember is that dynamite does in fact come in small packages. The same can be true of a good quality sound system for your car, truck, or SUV. You can elect to have the full range sound package. This package, if not custom installed by the dealer can take up a great deal of real estate within your car, truck, or SUV. If you own a compact car, these types of speakers and this particular type of sound system is definitely not recommended. The first reason it is unattractive is that it will most likely require either the vast majority of your trunk or take out your back seat. I for one like being able to cart around frie...

Technology is advancing at an alarming pace. Many of us in the market for auto sound systems have been more than surprised at many of the choices on the market today. Sound systems have gone far beyond the simple tuners of days past and are incorporating other features into the sound system as well. Today you can find all kinds of bells and whistles with price tags to match. It would be very easy to spend two or three thousand dollars in the purchase and installation of a very nice auto sound system in your car, truck, or SUV. Most of us, however, would do just as well with a simple three hundred dollar sound system and would be unlikely to use many of the features that the higher price sound systems offer. That being said, if you plan to be in the market for an auto sound system, a DVD players/entertainment system, an MP3 player, a CD player, and/or a navigation system for your vehicle, then you might want to select one of the more feature rich auto systems that are available on the m...

Many people who live close to the ocean have the benefit of being lulled to sleep by the sound of the surf. This circuit may provide a similar benefit to all those poor unfortunates who don’t live near the seaside but who do have the small consolation that they don’t have to worry about rust and corrosion in a salty atmosphere. The circuit consists of four unsynchronised oscillators which are mixed together to modulate a white noise source to simulate the more or less random nature of surf sounds. You won’t hear the waves crashing but the ebb and flow of the white noise will help mask other noises which would otherwise disturb your sleep. The four oscillators are based on four op amps in a TL074 or TL084 quad op amp package (IC1). IC1a, IC1b, IC1c & IC1d are configured as Schmitt trigger oscillators with their operating frequencies defined by the resistor connected between their outputs (pins 1, 7, 8 & 14) and the respective inverting inputs (pins 2, 6, 9 & 13), as well as ...

Control by sound may be very useful,  not just on a robot but also for a bit  of home automation, for example a  sound activated light responding to a  knock on the door or a hand clap. The  light will be automatically switched  off after a few seconds. An alternative  use is burglar protection — if someone  wants to open the door or break some-thing the light will come on, suggesting  that someone’s at home. The circuit can work from any 5– 12 VDC regulated power supply pro-vided a relay with the suitable coil voltage is used.   Circuit diagram :   Sound Activated Switch Circuit Diagram When you first connect the supply  voltage to the circuit, the relay will  be energised because of the effect of capacitor C2. Allow a few seconds for  the relay to be switched off. You can  increase or decrease the ‘on’ period  by changing the value of C2. A higher  value results in a longer ‘on’ period,  and vi...

If you are in the market for a brand new surround sound system I'm pretty sure you've been a little baffled by all the options, bells, whistles, gadgets, gizmos, and price tags on the market today. Trust me, you are not alone. One of the most baffling things to many potential surround sound system consumers is where on earth should you put all the speakers. I intend to answer that question and a few more over the course of the next few paragraphs and hope that you will read along. The first thing you need to understand is that there are several different types of surround sound systems. The industry standard and most common is the 5.1 channel surround sound system . This set up calls for the use of five speakers plus one subwoofer in addition to the receiver. The five speakers are the front speakers which include a left, right, and center speaker and the left and right surround speakers that are located to the left and right from the rear. You should also have a subwoofer locat...