This is a beta release of the PIXpand project. The PIXpand which is a device that connects to a TI calculator and enable it to store and retreive data to and from Playstation Memory cards. I am making this beta release as I do not have the time to continue....

A milliohmmeter is just the tool for checking trace resistance on a printed circuit board, tracking down shorted traces, and measuring the contact resistance of a switch or connector. Its the kind of tool that would come in real handy occasionally, but not....

The primary advantage of this method of bridging is that no additional components are needed (which means that it is cheap), and there is no signal degradation from additional opamps in the circuit path. The results are at least as good as using an external....

The electronic lantern control circuit adds high-efficiency dimming and flashing to an existing battery-powered lantern or flashlight or to a custom design. For the car it makes a great lamp for changing a flat tire, back seat reading or emergency engine....

This preamplifier was designed to cope with CD players, tuners, tape recorders etc., providing an ac voltage gain of 4, in order to drive less sensitive power amplifiers. As modern Hi-Fi home equipment is frequently fitted with small loudspeaker cabinets,....

The circuit of AM transmitter is designed to transmit (amplitude modulated) DSB (double side band) signals. A modulated AM signal consists of a carrier and two symetrically spaced side bands. The two side bands have the same amplitude and carry the same....

You may wish to use a 12 to 24V battery, like a Gel Cell, since the car power or cheap power wall wart style supply is probably too noisy. You may have to adjust the resistor value (1.2K for 24V). Whatever gets the phones working and does not use more than....

The only SOT-23 op amps featuring Over-The-TopTM operation the ability to operate with either or both inputs above the positive railare the 55mA LT®1782 and the 300mA LT1783. This feature is important in many currentsensing applications, where the inputs....

This adaptor will capture plots or prints of your GPIB instrument to your PC through the USB port. It fills the need of anybody who has a test instrument with the GPIB port and likes to get the screen dump on his PC without any GPIB card or complex software.....

This circuit is a frequency meter, low cost. It covers region 1HZ until 1MHZ. The IC1 schmitt trigger that it regulates the signal of entry and him changes in reasonable level suitable for the IC2-3-4. With the tenth pulse in the entry of IC2/1, is produced....

This amplifier was born out of a need to use two sets headphones with my computer's sound-card. The design presented here is a 50mW power amplifier meant for phones with impedances of 32 Ohms and greater. I chose this class A topology, because it offers very....

I designed this circuit for one friend of mine to be used as a small portable DJ mixer. The circuit is an audio mixer circuit so simple as it can be. There are two dual logarithmic potentiometers in the circuit to adjust the input signal levels and some....

When building amplifiers, it is often necessary to test transistors, either to verify that they (still) work, or for some esoteric designs it may even be necessary to match certain characteristics. The design featured here is just what you need, and....

You can build an automatic gain control AGC for the superhet receiver with only a few additional components. The first AGC circuit is more universal. It is suitable for audio amplifiers with dual op amps like TL072, TL082, NE5532 and the broadband amp NE592....

The main part of this circuit is the LM386 amplifier chip. It also uses a transistor input to buffer the input signal and provide extra gain for the LM386. The little unit has helped me out on numerous occasions when trouble shooting any amplifier circuit....

Double-tone Police sound Single-tone old ambulance sound This circuit is intended for children fun, and can be installed on bicycles, battery powered cars and motorcycles, but also on models and various games and toys. With SW1 positioned as shown in the....

This design is based on the video DVM design. Furthermore, it adds support for color, so you will get red and green semaphore lights (as those in formula 1) and sound: you will even hear the starting-horn sound! Up to 3 times are displayed on YOUR TV....

The idea to produce a standard TV PAL signal using a SVGA graphics card was born a few years ago, where cheap graphics cards with TV output were still not available. To achieve a CCIR conform TV signal with 50 Hz vertical interlaced refresh and 15.625 kHz....

the AD844 was still used, but this time the feedback loop went all the way from output and back to input. The DC servo was removed and the current source was made faster, using an extra transistor. The local feedback was turned into global feedback, lowering....

PC parallel port was never designed to provide any output power to divices connected to it. it was only designed for connecting printer to your PC. But in this weird PC business everything changes. Suddenly the parallel port have become a port where you can....

20W Bridge Audio Amplifier kit, based on the TDA2005 IC, a class B dual audio amplifier, specifically designed for car radio applications etc...

Simple circuitry suitable for moving-magnet cartridges Passive high-frequency equalization. This simple but efficient circuit devised for cheap moving-magnet cartridges, can be used in connection with the audio power amplifiers shown in these webpages,....

Correctly adjusted, the voltage on the pot wiper is slightly less than half D+ (appx. 0.47*D+) and Q1 will conduct if (D+)-(Vp)>6.2+0.7+0.7, or 0.53*(D+) > 7.6V, (D+) > 14.3V. If D+ is lower than 13.7V, Q1 will not conduct, Q2 will get driven via....

With AudioWave 2.0 your soundcard becomes a comfortable LF-signal-generator, which produces signals from 1Hz to 20 kHz with a resolution of 1 Hz. Phase shift between left and right channel is adjustable from 180° to +180° and an attenuator can be used for....

The reader mechanism shown was purchased from All Electronics for $1.50. The unit provides the magnetic head on a spring mechanism along with low level head signal amplifiers and data slicers. Three signal lines comming from the unit provide card presence,....

BFO is a simple device which helps us to listen SSB and CW transmissions. Reception of SSB and CW signals requires a product detector or BFO (Beat Frequency Oscillator) to reinsert the missing carrier. This circuit is very simple since it requires no turned....

This mini audio amplifier will test the audio stages in amplifiers such as the front end of FM bugs. You can also use it on lots of our other projects as well as the output stages of radios. It is a very handy piece of test equipment and will make a perfect....

This design uses a smart card to enable a relay. A Nutchip recognizes its mating smart card among thousand similar ones, because you choose the code to be programmed in the card's memory. No speacilized knowledge is necessary, as we supply the card program....

This new FM transmitter is very easy to make and doesn't need any RF tuning. First of all ,we have used an integrated VCO: The POS150 from Mini-circuits. This excellent RF circuit covers all the FM Band in a voltage range of 4V to 8V. The Kvco factor is very....

The ATV exciter described here uses a pair of Hamtronics model TA451 2-watt narrow-band FM voice transmitters to develop video and audio carriers on 439.250 MHz and 443.750 MHz. The TA451 is a single board, phase modulated exciter designed for amateur radio....

Following a hunch, the author discovered (or re-discovered?) that all plants carry an electric charge relative to the ground. This charge is more or less constant regardless of the size of the plant - a kind of "background voltage" in nature. This electric....

This preamplifier is requirement result of many friends to give a high quality preamplifier, capable to drive high quality power amplifiers with good sound, it`s not however difficult to making, it combines simplicity and handiness. It does not allocate a....