Spectrum analyzer + watch Two lights-emitting diode 5*8 matrixes where used to construct a computer controlled spectrum analyzer and clock. Microcontroller ATMEL AT90S2313 is the heart of device. The controllers accepts data from a serial port and with the help of conclusions of port B and the additional decoder 74145 is deduce a spectrum on the light-emitting diode screen are collected from two matrixes. 300W 6xLM3886 bridged-paralleled power amplifier That’s a well designed audio power amplifier capable for delivering pure 300W on 4 Ohm speakers. The design is based on 6x LM3886 (High-Performance 68W Audio Power Amplifier chip). The main design concept uses two boards of 3 x LM3886 each one, bridged together. The amplifier is configured in push- pull topology so that total gain of the amplifier is doubled. Stereo tape head preamplifier using LA3161 The Stereo Tape Head Preamplifier kit is based on LA3161 IC from SANYO. * Power supply - 9 ~ 12 VDC @ 20 mA * Output power - upto 200 mW * Input Resistance - 100 KΩ (Typ), Load Resistance - 10 KΩ (Typ) * Low noise, good ripple rejection owing to the on-chip voltage regulator * Berg pins for connecting power supply, input and output * Power-On LED indicator * Four mounting holes of 3.2 mm each * PCB dimensions 51 mm x 54 mm PIC16F84A Nixie Clock A very compact nixie clock based on PIC16F84A and 74141 driver IC and MPSA92 high voltage transistors. Electronic synthesizer The heart of the synthesizer is a set of 2 Analog Devices AD9850 direct digital synthesis (DDS) chips. These provide 2 channels of sinewave output which may differ in frequency and relative phase. The output stage of the synthesizer also includes separate variable attenuators for the 2 channels. These attenuators have a range of 0.0 - 63.9 dB of attenuation, in 0.1 dB steps. The user therefore has control over five parameters: 2 output frequencies, 2 output attenuations, and relative phase between the 2 channels. HALO2 High Altitude Balloon Another successful high altitude balloon flight with some gorgeous images. Alexei writes: High altitude ballooning is an emerging hobby, since the price of GPS and communications equipment has gotten quite low. It is an excellent hobby for people fascinated by space flight and telerobotics and has many learning aspects — from systems design to electronics design to software engineering. There is also an exciting risk factor, namely, that you could lose your precious electronics if something malfunctions. In this project, many of my interest and knowledge areas came together. Also, I have verified that the Earth is indeed round and that space is black. General purpose infrared remote control receiver with RS232 output I have done a simple infrared remote control receiver with RS232 ascii output. It can be used for developing remote controls on a PC using the serial port. In practice, the infrared bursts are converted in ascii characters and sent to the RS232 port. The downloadable ZIP file contains the schematic diagram , the printed circuit board, the components disposition and the object file to write into the ATMEL ATtiny2313 microcontroller. Homebuilt MP3 Player If you’re looking for a build-it-yourself, standalone, USB harddrive based MP3 player, this may be of interest to you. Originally conceived as a replacement for a CD player, this unit sits on the shelf next to your stereo and connects via standard RCA line-out audio connectors.This is an open-source project. Full hardware schematics and software source code are freely available on this site. As long as it’s for non-commercial use in whole or in part, you may use and modify this design to your heart’s content. [via] Infrared cordless Headphone Amplifier Using this low cost Project one can reproduce AUDIO from TV without disturbing anyone. It does not use any wire between TV and HEADPHONE. In place of pair of wires it uses invisible Infrared light to transmit audio signals from TV to Headphone. Without using any lens a range of up to 6 meters is possible. Range can be extended by using Lenses and Reflectors with IR sensors comprising transmitters and receivers. IR transmitter uses two-stage transistor amplifier to drive two IR leds connected in series. An audio output transformer is used (in reverse) to couple Audio output from TV to the IR transmitter. LED Desktop Clock This project uses RGB LEDs to create a clock face. Each hand is assigned a colour and as the hands overlap on the face of the clock it mixes the colours. The clock uses a single AA battery to power the display which is boosted to 5 volts with a switching mode power supply. The power supply should be able to use any AA battery that is at 0.7 volts or higher, which means that it should still work fine with AA batteries that may be “dead” when used in other devices. The heart of the clock is a DS1307 realtime clock with a CR2032 coin cell battery backup. The battery should be sufficient to keep the time for at least a couple of years. |
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