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InTech Open Access Publisher - Open Science Open Minds
Sound Star KIT with 60 LEDs Microphone and Vu-Meter
Using the Panasonic WM61A as a Measurement Microphone
Measurement microphones differ from recording microphones and sound meters-they have a flat response, (usually to well below 20 Hz. , and above 20 kHz. , ) and do not have "weighted, " or equalized frequency response. They are also optimized for measuringhigh SPL sound intensity, (for example, measurements taken at fraction of an inch from a...
48v phantom microphone power supply
48 V phantom` powering has become the standard for professional condenser microphones. The supply (or rather bias) voltage is applied over both wires of the balanced screened cable via two 6k8 resistors (see reference ) the absolute value is not critical, since a variation of ±20% is permitted, but they must be matched to an accuracy of 0.
FM Wireless Microphone
Here is a very simple, inexpensive and interesting project which provides lot of fun to a home experimenter or hobbyist. This simple transmitter can transmit speech over a short range. It can be used as a simple cordless microphone. The circuit uses two integrated circuits from Maxim. IC1 a MAX4467, is an amplifier raising the microphone signal to
Quality Stereo Wireless Microphone or Audio Link
This stereo FM wireless microphone also makes a great quality audio link. We tested it to beyond 50 meters and it was rock solid. It`s certainly not the first wireless microphone we`ve ever published but this one is a little different. It`s stereo, providing surprisingly good quality sound. Second, it has a really good range. We tested it at well
Outdoor surveillance with condenser microphones
Condenser Microphones typically sound better than dynamic microphones. If you are unfamiliar with these two types of microphones you may want to read about them in this Wikipedia article. Electret condenser microphones have to little plates (capacitor), one of which vibrates in the presence of sound. The varying capacitance is turned into an elec
Microphone AGC amplifier
A homebrew 2M transceiver I wanted to use it mobile so I wouldn`t have been able to use a fist mike. I had the bright idea of using one of those cheap personal hands free kits you can buy for mobile phones, however once installed reality struck home - hardly any audio! Like the microphone amplifier of many Ex PMR radios and lowcost hand helds,...
Microphone Mixer Tone control
1.5V miniature wireless FM microphone circuit
The circuit shown in this paper uses 12 components to form a miniature wireless FM microphone with stable operating frequency, and its transmitting distance is about 30 meters and more than 100 meters at 6V power supply.The circuit is shown as Figure, BG1, C1 and C3 form a high - frequency oscillation circuit. The transmitting distance is...
Simple long-distance wireless FM microphone circuit
The the loop antenna L1 for emission also serves as the oscillation coil, the high-frequency current flowing in antenna is synchronized resonance with the oscillation frequency, so it is always in the best emission state. Accoring to practice, launching distance is about 100 ~ 150m in empty mine. In contrast, in the case of equal working...
Dynamic Microphone Pre-Amplifier
Dynamic microphone uses a moving coil around magnetic field to convert mechanical movement into electrical signal. The ordinary mini speaker is turned into a..
Microphone or Electric Guitar Pre-Amplifier with Noise Gate and Compression
In personal electronics and computer audio system, the SSM2167 is a complete and flexible solution for conditioning microphone inputs. It is also very good for..
An op-amp IC (741) amplifies the audio signal from MIC1, and R12 controls its gain. Audio is fed to the oscillator circuit Q1 and related components. D2 is a varactor diode. Audio fed to D2 causes FM of the oscillator signal. L1 is 1/2 turns of #18 wire on a He" diameter form. The antenna is a 12" whip.
Phantom and T powering for condenser microphones
An RF condenser design, it was powered by 12v, supplied to the microphone via the mike cable using a phantom circuit. This is the first known usage of a phantom circuit for microphone powering. Sometime around 1970, Neumann introduced the Fet-80 series of condenser microphones that were solid state and remotely powered via the microphone...
Converting an EV PL-76 or 1776 microphone to p48 powering
The resistors could be 1/8w, The zener diode could be a 250mW part, or it could be a 1W part (1N number will be different). The electrolytic capacitor is plain vanilla, and the value can deviate (larger is ok, higher voltage is ok), but when it`s all done, it has to fit inside the battery compartment. Cut a piece of vectorboard that fits across...
electret microphone amplifier
Level refers to the relative strength of the signal and is measured in decibels. LINE level sources are much-amplified signals over MIC (microphone) level signals. Line level is usually between -10 to +4 dbm in strength while MIC levels are normally -60 dbm. The line output standard designed to drive a load of 600 ohms or greater, at a mean...
Op-Amp Microphone Preamp
A high quality microphone preamplifier using a single power supply, suitable for dynamic or electret microphones. The op-amp used can be any low noise, high performance type, e. g. NE5534, TL071, OPA 371 etc Nothing too special here. The schematic is shown using a dynamic microphone, for use with an electret a suitable biasing resistor is...
Microphones schematics and documents
The power supply was built into the base of the mic which can lead to hum issues despite the on-board potentiometer that acts as a `null`. This also means that the mic has two cables running from it - one for power and one for audio. Both mics use two-stage head amplifiers based around an ECC83 tube, and both have unbalanced outputs. Here are...
Compressor For Electret Microphone
The FM Remote Control Receiver` (available on this website in Infra-red circuits section) has a connector where an analogue output is made available. To make a simple intercom or P. A. system the associated transmitter needs a microphone pre-amplifier that outputs a signal at the correct level. And that is exactly the function of this circuit. Actu
Operational Amplifier Video Tutorial and super microphone circuit with LM324
Afroman goes over the basics of how to use an operational amplifier to amplify tiny voltages, and builds a circuit to listen to very faint sounds with a microphone. For more information about amplifiers, Google inverting amplifier non-inverting amplifier instrumentation amplifier class A amplifier class B amplifier class AB amplif
Audio Filters Circuits
Audio Amplifier Circuits
Audio Oscillator Circuits
Audio Mixer Circuits
Audio Equalizer Circuits
Audio Tone Balance Circuits
Beeper Buzzer Circuits
Vacuum-Tube Valves Circuits
Musical & Effects Circuits
Ultrasonic distance finder circuit
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is measured. There are three main categories of distance measurement methods in use: a) By...
Simple Metal detector circuit with CD4030
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to find something potentially valuable, hidden a few centimeters below the soil. So many...
Fully automatic watering circuit for flower pots
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This circuit comes as a solution to this problem. Depending on humidity of the pot at...
Simple deep searching metal detector circuit
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the circuit of this metal detector, it is possible to detect a metal coin in depth of 90 to...
Sub-Harmonic Bass Converter for Electric Guitars
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound, such as filtering or distortion. Instead, a frequency division system produces outputs...
Echo Depth Sounding Sonar for Boats
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the calibration of the rope. This arrangement still exists in some yachts. The big...
100W HiFi Audio Amplifier Circuit
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power supply must be symmetrical so that no electrolytic capacitors are needed at the outlet....
Plant-Pot Water Level Indicator Circuit
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower. The circuit of the device is shown in Figure 2. The water detection is made from the bottom...
Analogue Sound Preasure dB-Meter Circuit
The best human ear can capture sounds from 20Hz to 20KHz. These limits are known to be the broadest that can exist. Normally the normal limits range from 100Hz to about 13KHz and depend on the age and health of the individual. We for our measurements and to have a good accuracy we will get the limits of 20Hz to 20KHz. A sound to be heard does...
DIY HV Variable Capacitor
DIY PMA Alternator Plans
Digital Signal Integrity