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Electronic Projects to Build
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Links to electronic circuits, electronic schematics, designs for engineers, hobbyists, students & inventors:

EDFET Buffer -  Two of things you have to consider when adding a power output stage to an op-amp circuit are the frequency response and the cross-over distortion in that stage.  This is especially true with wide band amplifiers, where the unity gain crossover needs to be at several hundred kilohertz.  The stage is __ Designed by Dick Cappels

EEPROM Driver for 24LC64, 128 & 256 AVR Controllers -  i had been putting off writing a driver for some 24LC64 and 24LC256 EEPROMS I was thinking about using, when I came across a temperature logger application written by Sean Ellis.  The Temperature logger was posted on on www.  avrfreaks.  net on January 10, 2002, project iD 49.  The original application was written for the ATtiny15, which has a small hardware stack, so when extracting the i2C code, I massaged it a little bit to make it more compact when running on processors equipped with a RAM stack while making it a little easier to customize for new applications.   __ Designed by Dick Cappels

Egyption Talking Frog Box -  This device 'listens' to a conversations and then interjects words and phrases at inappropriate times.   __ Designed by Luhan Monat-Mesa Arizona

Electric cockroach zapper -  Using a PIC  for this device provides a lot of useful functionality.  The timing for the power pulse to the inductor is critical to getting the best Zap from your nine volt battery.  The longer the current is on, the higher the voltage.  Once the inductor reaches saturation, however, you are just waisting power.   __ Designed by Luhan Monat-Mesa Arizona

Electric powered Go-Cart  -  We made the test a few times indoor becoarse it was rainning and windy as usual outside, WOW I was happy and my kid was more than thrilled, the motor force and speed is more than we could dream of!  __ Designed by Thomas Scherrer OZ2CPU

Electronic Card Lock for Appliances -  The circuit presented here can be used as a lock for important electronic and electrical appliances.  When a card is inserted inside its mechanism, depending upon the positions of the holes...__ Electronics Projects for You

Electronic Dazer -  The Electronic Dazer is a modern, portable, personal-protection appliance.  it generates hight potential energy to ward off vicious animals or other attackers.  it is an aid to help exape from a potentially dangerous situation.  the device develops about 2, 000 volts.  Higher voltages mabe be attained by adding aditional multiplier stages, but it should be noted that those stage will also increase the overall size of the unit. 
The Dazer is very compact, being built into a small plastic case.  it is powered by a single 9-volt battery, either NIC ad or alkaline. (Editor's Note: the so-called 9-V NIC ad actually provides only about 7.5V.  Why? NIC ad cells only give 1.25 per cell.6 cells in a 9volt battery gives it 7.5V and so the Alkaline type would be a better choice).   __ Designed by Rick Duker

Electronic Dice -  A LED dice, bright, unbiased, and spectacular.  The display uses 7 LEDs to simulate the faces of a real dice.   __ Designed by Projects & Ideas from Nutchip.com

Electronic Dice -  The 555 timer IC is connected for Astable Operation, the clock pulses are fed to the 4017 IC via the 10K resistor.  The 4017 is a 10 stage counter, output 6 (pin 5) is connected to RESET (pin 15) , thus giving us a 6 stage counter , outputs 0 to 5.6 of the LEDs are connected as 3 pairs, thus requiring 4 different signals, these signals come from the 4 transistors, which in turn __ Designed by Andy Clarkson

Electronic Thermostat for Fridge -  A thermostat is a standard equipment for sensing temperature of a system and maintaining it at a pre-defined point.  it is a regular feature in air-conditioners, room heaters and refrigerators.  Although...__ Electronics Projects for You

Emergency Power -  This unit was constructed in a plastic 4-outlet juction box ($5 from Home Depot).  The front panel is cut from 60-thou Lexan, and a scrapped Pep-Boys battery charger provided the transformer.  The PIC 16F870 keeps track of battery voltage as well as both charging and discharging currents.   __ Designed by Luhan Monat - Mesa Arizona

Encoder-Adjustable Display -  This circuit has been developed as a semester work for an Electronics class.  it features a 7-segment display.  The number is set with a quadrature encoder: turning the encoder knob you can adjust the number shown.  Building and understanding it you will test your knowledge about interfacing to an encoder, counting, and driving a display to show the information.   __ Designed by Projects & Ideas from Nutchip.com

Exercise Bike Power Generator -  An exercise bike is fitted with a permanent DC magnet motor, which, charges a 12VDC lead-acid automotive battery.  This battery can be used to directly drive DC loads or can be fitted with an AC inverter to drive regular house-hold loads.  The system is interfaced through the PC to allow data-logging and monitoring of both instantaneous current, voltage and power along with accumulated power.   __ Designed by Greg Miller

Experimental 1 kHz Synchronous Demodulator -  This circuit employs a synchronous demodulator to separate a 1 KHz signal from noise and measuresthe amplitude of the 1 kHz signals once a second at about 60 microvolts per count then sends the measurements via an RS-232 interface for further processing or display.  An LED on the board also lights when the measured signal exceeds a preset threshold __ Designed by Dick Cappels

Fabricate a High-Resolution Sensor-To-USB Interface -  11/17/11  EDN Design Ideas:  A precision analog acquisition system fits in your pocket.  The circuit in this Design idea combines a mixed-signal microcontroller, a USB UART (universal asynchronous receiver/transmitter) , and a novel adaptable analog sensor-input circuit.  it allows you to connect many types of sensors to the designís two analog-input channels, control the device, and read measurement data on a USB host.  The USB connection powers the circuit.  You can control the device from your computer with simple commands; even terminal software can make the measurements __ Circuit Design by Zoltan Gingl, University of Szeged, Szeged, Hungary

Faradayís Guitar -  Experimenting with the fundamentals of electrical and electronics is always interesting.  Presented here is an electronic circuit that demonstrates Faradayís law of electromagnetic induction and gives musical output.  The law talks...__ Electronics Projects for You

Fast precision LED driver -  The circuit allows a precision regulated drive current to be set to drive an LED, and in response to a TTL level signal, the LED is switched on and off with rise and fall times of less than 500 nanoseconds and less than 7% overshoot.  This was designed for biological experiments to study the photo repsonse of cone cells rabbit eyes __ Designed by Dick Cappels

FET Transistor Homemade from Cadmium Sulfide Photocell -  Homemade FET Transistor Made From Cadmium Sulfide Photoresistor.   __ Designed by Nyle Steiner K7NS

Field Strength Indicator-Analog only -  The circuit is powerd by a single 1.5 volt AA cell.  The current drain is so small, about 60 microamps, I didn't bother with an on-off switch -i just slip a battery in for the day, and hope I remember to remove it when i'm done.  The supply voltage can be increased up to the breakdown voltage of the transistors to increase the sensitivity, but beware - the sensitivty to thermal drift will increase as well.   __ Designed by Dick Cappels

Finite State Machine Programmable Logic Controller -  Finite State Machine based Programmable Logic Controller.7 inputs  8 Outputs  Simple iF/THEN/ELSE based compiler language generates direct EPROM files.   __ Designed by David L. Jones

Fire Alarm with a Thermistor -  This project can effectively be used as a temperature-sensing fire alarm.  Here, an NTC thermistor is used as the temperature sensor.  Resistance of the NTC thermistor decreases with an increase in...__ Electronics Projects for You

Fish Tank Lights & Temperature Sensor -  There are 6 modes in total 4 solid color modes (Blue, Red, Green, White) and 2 "cycle" modes.  The cycle modes allow the lights to do a slow transition from one color to the next.   __ Designed by Alan Parekh

Flame Triode with Gain -  i have found a simple way to make a triode with gain using an alcohol flame.  This flame triode exhibits both power gain and voltage gain.  By making a flame dual triode, I have been able to make a free running multivibrator oscillator and code practice oscillator.  I also observed a very intriguing phenomenon of flame electrical conductivity; that electrons from a cathode, placed inside of the flame, can flow to the anode even when the anode appears to be placed well outside of the flame.   __ Designed by Nyle Steiner K7NS

Flashing Red LED Light-1970's Style Caboose Marker -  A circuit that drives a red LED from a 1.5 volt battery and simulates an incandescent light.  Duty cycle can be changed by selecting resistor values __ Designed by Dick Cappels

Flying inductor LED series voltage boost -  A circuit that goes in series with a white LED and a 1.5 volt cell to make > 3 Volts to drive a white LED __ Designed by Dick Cappels

Flying Saucer -  This project was inspired by one of those solar powered lawn lights.  I had taken the bottom off of one and hung it in a tree.  A neighbor commented that it resembled a small flying saucer.  Hmmmm.   __ Designed by Luhan Monat - Mesa Arizona

FM Broadcast Audio Transmitter -  A nice AC mains powered transmitter with pre-emphasis, audio level control, and tuning control.  Notice: Before operating a radio transmitter, find out what kind of transmitter operation, if any, is permitted in your locality.  Radio transmitter operation is a serious legal matter.  in the United States, operation of unlicensed intentional radiators is covered by Part 15 of Title 47 of the Code of Federal Regulations.  This design can be readily adapted to different frequencies and different power levels.  if you choose to build and operate the transmitter described here, you do so at your own risk.  i'm only publishing this as an example of what can be done.   __ Designed by Dick Cappels

FM Transmitter with Crystal Referenced PLL Frequency Control using LMX1601 ATtiny2313, AT90S2313   -  An LMX1601 Phase locked loop, a discreetFET VCO, and an AVR micro controller combine to make a stable, easy to use monophonic FM transmitter that includes a an audio activated switch that turns the transmitter on only when its being used __ Designed by Dick Cappels

Foolproof prototyping chassis -  Here's my solution for a prototyping chassis.  The H-frame is borrowed from an antique transistor tester chassis.  Even the tallest tubes, placed on the middle deck, are within the H-profile, so it can be rolled on any side safely.  instead of drilling all sorts of socket holes on the steel deck, I use disposable top boards made of laminated floor chipboard.   __ Contact klausmobile @ yahoo.Com

Four-Channel Video & Audio Sequencer -  This next project is a simple circuit for switching your CCTV camera outputs sequentially.  it switches four video and audio channels sequentially, one at a time. it is built around a 555 timer few other components.  The timer is configured as an astable multi-vibrator.  A single-side PCB of the four-channel video and audio sequencer is provided along with the component layout.  After assembling the circuit on the PCB, enclose it in a suitable plastic box.__ Electronics Projects for You

Frequency Meter & Pulse Generator -  Simplicity in circuitry was the design direction.  Zero mass (firmware only with no physical components) would the ultimate achievement.  This instrument doesn't have any front panel controls because the user interacts via an RS-232 terminal program at 9600 baud.  I needed a frequency meter for my experiments in Nondu, Thailand, where I really don't have room for a lot of instruments.  I wrote some straight forward code to read the 16 bit counter in the AT90S2313 after period of time, which was determined by running a timing loop.  By the way, I tried various approaches using interrupts from the 8 bit timer to set the counting interval, but found timing uncertainty resulted in intolerable jitter in the measurements, to as inelegant as it is, timing loops turned out the be give the best results.  The results of the counts are converted to acsii and sent to the terminal.  After finishing the frequency meter, I realized that only half the Flash ROM was used and that I could fit a handy pulse generator program I found on the web into the same chip, but having two instruments in one.  The result is a combined counter and frequency meter.  The chip flips between the two programs, The only things common between the two programs is some initialization and some of the serial port i/O code.  The pulse generator firmware is pretty much as originally published, except that I modified it to drive a resistor network so as to allow the pulse output amplitude to be selectable.   __ Designed by Dick Cappels

Frequency Meter with 100 MHz RF Desktop channel  -  This basically the frequency meter section of the frequency meter/pulse generator based on the AT90S2313 described elsewhere on this site, combined with the 100 MHz RF interface described in the page about the RS-232 to 100 MHz RF desktop channel adapter.  Built and align this is the same manner as the 100 MHz RF desktop channel adapter.  The frequency meter __ Designed by Dick Cappels

Frequency Meter with Minimum Mass Wireless Coupler -  A 0 to 2 MHz ferquency meter with a Minimum Mass Wireless Coupler, based on the ATMega8.  Range to the Minimum Mass Base Unit is 10 to 15 cm.  Since the frequency meter is battery operated, it can be floated from ground, making life in and around the test bench a lot simpler.  No need to connect it to the computer or LCD display __ Designed by Dick Cappels

Frequency meter with wireless Data Channel -  This basically the frequency meter section of the frequency meter/pulse generator based on the AT90S2313 described elsewhere on this site, combined with the 100 MHz RF interface described in the page about the RS-232 to 100 MHz RF desktop channel adapter.  Built and align this is the same manner as the 100 MHz RF desktop channel adapter.  The frequency meter __ Designed by Dick Cappels

Front Panels the Mouse Mat Way -    NOTE: Must register on this site __ Designed by Published in Elecktor July/Aug, 2010

Full Circle LED -  Schematic + info + pictures __ Designed by Lennie Zink

Function Generator Sine / Triangle / Square / SaW / Burst Sweep Noise based on PIC16F870 -  PIC  Project  Sine Triangle Square Saw Burst Sweep Noise - runs on a PIC 16F870 __ Designed by Luhan Monat - Mesa Arizona

Furby Resurrection -  PIC  Project  There are several websites documenting the original Furby circuit board.  I decided to replace the original circuit entirely and replace it with a PIC  based controller.   __ Designed by Luhan Monat - Mesa Arizona

Gainclone for the PC Age -  Audio input comes from either the Line-Out of the PC or an external sound card (described later).  A small filter consisting of 680Ω/47pF excludes any RF signals from entering the case.470nF input capacitor should have a high voltage rating since it protects against line voltages being connected to the amplifier, since it is in the signal path it should be a high quality type __ Designed by Malcolm Rix

Get Set Go with Raspberry Pi Camera -  This project describes how to connect a web camera to the Raspberry Pi and make use of it.  Raspberry Pi board has an onboard connector which can be used for connecting...__ Electronics Projects for You


Electronic Construction Projects: 
#'s - B         C - D         E - G        H - K         L - P         Q - S         T - Z

 


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