Thursday, August 25, 2011

Mosquito Repeller

Description: The following diagram shows the electronic mosquito repellent. Features: The piezoelectric buzzer converts the amplifier output of ultrasound can be heard by the insects, an amplifier consisting of four transistors, mosquitoes can be postponed by the use of frequencies in the ultrasonic (above 20 kHz ) wide transistor to amplify the sound. Component: IC, transistor, resistor, President, condenser

Tascam MP-GT1

Tascam MP-GT1 to maintain the honor of being the first MP3 player designed for musicians. It is essentially a mobile guitar trainer, which will be enough memory for up to 240 songs. You can learn new riffs slow down guitar parts, loops, and also remove some parts. The MP3 playback is achieved through a variable speed audition, slows down the speed without changing pitch. You can also step up or down the current song to the tune guitar. MP-GT1 has a built-in tuner and a metronome, a graphic LCD display, and rotate the data for navigation. Tascam MP-GT1 is available in Japan since the end of this month at a price reserved.

Cracker Box IPod Amplifier

  1. Toggle switch, single pole single throw
  2. 9V battery
  3. 9V Battery connector
  4. 0.047µF capacitor
  5. 220µF capacitor (biggest)
  6. 0.01µf capacitor
  7. 100µf capacitor
  8. Hookup wire, 2 0 or 22 gauge AWG solid core is best.
  9. 5KO potentiometer (audio or log taper)
  10. 25-ohm (25O) rheostat
  11. LM386N audio amplifier
  12. 8-pin DIP IC socket
  13. Chicken head knobs (2)
  14. Prototyping PC board
  15. Speaker, 8 ohm impedance
  16. 10O resistor
  17. 1/4 mono phone jack

Monday, August 22, 2011


SigmaDSP ® digital audio processors allow the use of a fully programmable audio DSP that can be easily configured through the graphical development tool SigmaStudio ™. Latest SigmaDSP SigmaDSP products against the car audio and portable our best performance and power aware processors. The SigmaDSP ADAU1442, ADAU1445 and ADAU1446 combine a core of 172 MHz with an array of routing, including sample rate converters asynchronous and S / PDIF Rx / Tx. Routing matrix allows the connection of various digital sources operating at different sample rates to easily connect the audio processor.

The first low SigmaDSPs, ADAU1761 and ADAU1781, contains the same powerful SigmaDSP elsewhere, and is connected to a stereo ADC and DAC SNR performance to more than 100 dB. AD1940 and AD1941 role in the computing power of high I / O channel count. ADAU1701 and ADAU1702 include a complete analog I / O, Digital I / O and function of stand-alone system that offers full sound processing on a single chip. ADAU1401A ADAU1701 with similar functions, but is designed specifically for the automotive industry, as well as set a wide range of temperature.

The software tool Sigma graphical development studio, programming, development and optimization SigmaDSP audio processors. Familiar audio processing blocks can be interconnected in a pattern, and the compiler generates code DSP-ready and a control group of the surface for setting parameters and tuning. This tool allows DSP engineers with no experience writing code for easy implementation in a DSP design, but still strong enough to meet the demands of experienced designers DSP. sigma relations studio with two boards Analog Devices evaluation and design to provide complete production circuit in real-time control IC.

With flow charts DSP Development of the signal, including sigma studio includes more features to accelerate the design cycle of concept release product. Sigma Studio provides tools for intuitive mode control registers, the calculation of tables of filter coefficients, to visualize the size of the filter and phase responses, generates C header files, and sequencing of a series of controls to ease your transition from studio to sigma deployment of the system on your microcontroller.

Evaluation kits, including evaluation boards and tools are now available SigmaStudio full for all products SigmaDSP. Check the SigmaDSP FAQ for any questions you may have. If you answer no, please direct your request to or accessing the Forum SigmaDSP SigmaDSP EngineerZone.

Sunday, August 21, 2011

Audio Processor

This chip audio processor features SSM2045 IC is specially developed for applications in electronic music, and 741 IC OPAMP. The circuit is configured to low pass filter with gain control voltage. The input signal is set to work through the resistance level of 150mVpp R1.

The filter has two buffered outputs: the output at pin 2 to pins 1 and 4 output pins to pin 8th Internally, the outputs are connected to two voltage controlled amplifiers (VCA).

The R15 and R16 are connected to these outputs to achieve optimum shift control and elimination of tension.

P4 is the volume control. The current flowing to pin 15 and 16 should not go beyond the maximum of 250 uA. The remaining two OCV and the entire filter is controlled as a voltage range -250 mV to + 250 mV to pin 14th

This tension can be adjusted P2.

Input can be done by up to 200 Ω source impedance. When the input level of 0 dBm, the VAC decreases by 6 dB. Bias current required to pin 17 is between 120 and 185 uA uA. The cutoff frequency can be shifted from 20 Hz to 20 kHz with a connector 5 This variable can vary through the P1. Capacitance values ​​were chosen to give a Butterworth filter of its properties.

IC SSM2045 output power supply voltage 741 converted to AMP. All sybsequent DC is disconnected from the circuit IC2.
Noise voltage is about 80 dB

Friday, August 19, 2011

IK Multimedia iRig Mic

If you are an amateur or a professional and want to record the sound quality on your iPhone, iPod, iPhone, IK Multimedia has introduced the IRIG micro that can do just that. This hand-held microphone can be used to record anything anywhere, whether a musician to record a song or a journalist who wants to record an interview. It can also be used for podcasts - in fact, for any type of recording.

IPhone, iPod, and make the iPad has built-in microphone, but these do not produce great sound. IK Multimedia IRIG microphone to easily connect your device and you're ready to record good audio quality.

There are three levels to get the pass, which can be adjusted, depending on the type of sound you want. Although you can use it as a PDA, you can even put on a stand if you want a hands-free use. Thank you for your applications, you can add sounds to your songs, if you are recording tracks, for example.

Works with all audio applications, and provides real-time monitoring. As long as your expectations are realistic and you do not expect studio quality recording, you should be pretty happy with this microphone

Sony UWPV1/30320 Ch 30/33 UWP-C1 Wireless Package

Improvements include the system of all-metal body, which is robust and the transmitter, which has an input that is switchable microphone or line. In addition, this package is the synthesis control function that is included in the system PLL, the reception, which is a different space, and all the other features that were found in the UWP-C, in order to make a product so popular.

All the signals are coming in and the potential for radio interference is minimized and only the strongest signal thus selected. This is because this system is a very cool feature that allows the receiver (which can also be installed on the camera), the state of biodiversity, which stabilizes the reception. The device also provides a great clarity in the sound because of its versatility.

This system is equipped with antennas that are designed to pivot around which strengthens a result of the reception. There is also the provision of a mini-jack output for stereo is also integrated with a monitor to control the volume. Mini-stereo cables and XLR are included. All information about the channel and the frequency, the RF input level, time of operation, the battery and the state of the audio output is displayed on a LCD. The receiver and the body depending on the UHF frequencies are 188 in number and function normally no more than 8 hours. The batteries used for the operation of two alkaline AA-size batteries

Tuesday, August 16, 2011

Boss BF-2 flanger pedal schematic

The BF-2 was sold in 1980 but remains one of the most widely used analog flanger pedal. The 4 buttons (manual, depth, speed and resonance) allow users to shape the sound the way you want - from dynamic sound effects jet plane on short delay chorus and vibrato.

schematic :

Monday, August 15, 2011

Car/Bike USB Charger

Looking for a USB charger that can effectively operate from a 12V car battery? This device operates at 89% efficiency and can charge USB devices at currents up to 525mA. Best of all, it will not face battery when it is permanently connected, as long as you remember to unplug the USB device. There are lots of USB chargers on the market, but this unit has two stand-out features: high efficiency and low consumption in standby mode. In fact, his only 160μA standby current, a figure that is well below the self-discharge of most lead-acid batteries. This means you can leave the unit permanently connected, and it will not cause the battery to go flat (or at least not much faster than it would by itself).

While this may seem a very specific application, there are many other uses for low quiescent current 5V DC 12V DC. For example, remote monitoring stations often operate with a 12V SLA complemented by a solar panel. These stations are invariably a microcontroller and other circuits, which needs a supply of 3.3 V and 5V. Energy consumption in these devices is low most of the time, but sometimes the microcontroller wakes up and turn on a radio module and other circuits, which can draw more current. This charger can provide power - up to 500 mA - while being stingy with the battery when the battery is low. In addition, because of its effectiveness is high (89%), almost no battery is spent, even when the load is drawing 500mA.

USB Audio Interface

This circuit is the quality of a preamplifier with a built-in USB DAC Leachamp my power amplifier. The system is PCM2902 Datasheet. Circuit includes DAC and ADC, SPDIF input and output of HID and 3 + button to the MUTE, VOL-and VOL.

For playback of high quality requires an external low-drop voltage regulator for the DAC. LP2951CM DAC is used, which were easily available in local stores. Output voltage is fixed at about 3.7 V, with two resistors. The circuit was designed for the placement of the well and the separation of digital and analog ground. This land is connected to a certain point of the USB connector.
PCM2902 data sheet recommends connecting the low pass filter the DAC output to filter out frequencies above the audio band produced by the conversion of oversampling. Digital integrated circuits, which includes frequencies above 100 kHz LPF. Notes application filter sites recommended by the manufacturer of the first order LPF (simple RC), or 2 Amps order preamp works, it works well. I am a simple RC LPF with the recommended values ​​for R and C. 4N7 1k It 'best to use the scroll-ceramic capacitor in place. I did not hear the sound difference between the filter or not, but in relation to other components of the audio chain is best to use. The best cut-off frequency, which can change the value of the capacitor 3N3

HI-FI Stereo Headphone Amplifier



High performance - low noise and distortion
High and low impedance drives
High output power (up to 200mW;? At 8 and 32?)
Dual connectors for headphones - can drive two pairs!
Works with any power amp or line level audio

Measured performance:

Frequency Response ........................................................................... flat from 10Hz to 20kHz (see charts)
Nominal ....................................................................................... 200mW into 8? and 32?, 85mW at 600?
Max. output (current or voltage limited )........................ 575mW into 8?, 700mW into 32?, 130mW at 600?
Harmonic Distortion ...................................................................... Typically 0.0005% (600? Load) 0.001%
                                                                                                        (32? Load) and 0.005% (8? Charge)
Signal to Noise (weighted ).................................... -130 DB (600?),-120dB (32?) And 111dB (8?) For the 
                                                                                                                          output   power of 100mW.
Crosstalk ...................................................................... better than-68 dB from 20 Hz to 20 kHz at 100m? 
                                                                                                                            output power (see charts)
Input Impedance .................................... ~ 47k? | | 47pF
Output ..................... ~ 5?

Sunday, August 14, 2011

Audio Distribution with TL064

This project audio distribution in electronic circuits can be designed or TL06 TL064 operational amplifiers, and other common electronic components.

TL06 is made by Texas Instruments and a power amplifier running low. TL06 is a low power version of the TL08 series amplifiers operating.

The circuit is shown in this diagram is based on a TL06 (TL064 can be used) and is very useful in the distribution of the signal.

The main features TL06 are: very low power consumption, typical current consumption of 200 mA, wide common mode and differential voltage range Low input bias and offset currents, common mode input voltage range, output short circuit, high input impedance, internal frequency compensation, latchup-free, high slew rate.

With this scheme, you can distribute the audio signal from a signal source.

This pattern of electronic circuit project does not need multiple components and it is very easy to make, requiring a dual supply 15 volts.

Project DS1802 Digital Potentiometer

DS1802 is a dual beam audio potentiometer Manufactured by Dallas Semiconductor. DS1802 digital potentiometer can be used to replace standard mechanical potentiometer resistance.

Each potentiometer provides 65 wiper positions with increased increments of 1 dB and the device

mute. DS1802 digital potentiometer has two methods for controlling the device: push buttons and a serial interface 3 son controls the position of the wiper.

Using the push button control input is not necessary for a processor to work while using 3-son serial interface requires using a processor and allows the user to read or write precise positions towel two potentiometers.

Using a DS1802 with the push of a button can be configured to operate independently or "stereo" mode. Operation mode allows independent control of each independent potentiometer wiper during operation in stereo mode provides a control position in one of the potentiometer sliding tackle both.

This digitally controlled potentiometer circuit DS1802 provides only the volume, volume control and mute the audio signal.

The MAX4167 operational amplifiers connected to each output channel is needed in this circuit because the DS1802 wiper is a relatively high (output) resistance and without buffering, the DS1802 will operate 1mA load. If the load is capacitive, the output resistance fail to filter high-high frequencies.

This DS1802 circuit schematic is necessary to use the DC power output between 3 and 5 volts (2.7 to 5.5 at the maximum acceptable).

NJW1186 Surround Sound System

A very simple 5.1 surround audio system can be constructed using NJW1186 is a surround processor for 5.1 channel speaker system regenerates center, surround and subwoofer channel signal from normal stereo signal input. NJW1186 contains the passive matrix circuit, BPF with the center channel, LPF for the subwoofer, simulated stereo for the surround channels and size for each channel.

All internal status and variables are controlled by I2C bus.

As you can see from the diagram, this 5.1-channel surround sound system is very simple to design and require few external electronic components.

NJW1186 surround processor is manufactured by New Japan Radio Co. Ltd.

This draft of the electronic audio 5.1 surround sound processor can be powered from a wide range of input voltages from 7.5 volts to 13 volts.

Outputs of a surround system: subwoofer channel SWOUT, RSout-right surround channels, the left-channel output LSout surround channel field-Center.

Roland Boss HD2 Mega Distortion schematic

Wednesday, August 10, 2011

Low Noise Phono Preamp

This is a preamp for turntable / phono very simple, but has a noise dampening properties are excellent. This preamp using IC LM 381 National Semiconductor made ​​known very well in audio signal processing.

Parametric EQ

Simple parametric equalizer

Noise Limiter

The noise limiter circuit is easy to build, in collaboration with 4pin or 8pin BA741 very attentive, and uses a balanced diet. When the audio input level is between the output of 20mV and a constant signal is 20V 25mV. Audio limiters can be used in a scheme issuer or in any circuit you need a constant level.

R1 = 100K
R2 = 1K
R3 = 1M
R4 = 68K
R5 = 10K
C1 = 10uF
C2 = 680nF
T1 = BFW11
T2 = BC173C
IC = BA741

Thursday, August 4, 2011

Tone Control TDA1524A

This is a low noise and distortion pre-amplifier and tone negative feedback circuit in one module. Using a special IC TDA1524A, this simple circuit is simple to build and will drive most of power amplifier. 

Circuit Diagram
R1, R2__________________ 220R
R3, R4__________________ 4K7
R5______________________ 2K2
R6______________________ 1K

C1, 2, 7, 8, 17_________ 10 uF ecap
C3, 4___________________ 47 nF
C5, 6___________________ 15 nF
C9______________________ 220 nF poly
C10_____________________ 100 uF 25V
C11, 12, 13, 14, 16_____ 100 nF
C15_____________________ 1000 uF 35V
C18, 19_________________ 10 nF

IC1_____________________ TDA 1524A
IC2_____________________ LM 7812
P1______________________ 50k linear switch pot
P2, 3, 4________________ 50k linear pot
X1, 2, 3, 4_____________ RCA jack
D1______________________ Diode 1N4004
L1______________________ Red LED

Portable Audio Amplifier

Here for stereo audio input output.                          

This really is easy portable audio amplifier circuit. This circuit built based on IC TEA2025 which is a monolithic integrated audio amplifier in a 16-pin plastic dual in line package developed by UTC. Circuit has Internal Thermal Protector. It is designed for portable cassette players and radios. You can also use it as your PC Audio Amplifier.

 Here for mono audio input output (bridge).

 Stereo per channel
VCC=9V; RL=4 ohm/3W
VCC=9V; RL=8 ohm/2W
Bridge Application
VCC=9V; RL=8 ohm/5W
VCC=9V; RL=4 ohm/8W
Supply Voltage min = DC3v @ 500mA
Supply Voltage max = DC12v @ 500mA
Supply Voltage recommended = DC9v @500mA