Electronic Circuits and electronic circuits, electronic schematics plus an extensive resource for hobbyists, inventors and engineers

DiscoverCircuits.com has links to 45,000+ electronic circuits, cross-referenced
into 500+ categories.    We have searched the web to help you find quick design ideas.

HOME Schematics Hobby Corner Dave's Circuits Electronic Resources Contact Info
Imagineering Ezine    Discover Solar Energy Dave Johnson & Associates Faraday Touch Switches
Welcome to DiscoverCircuits.com - online since 2002

See Media Kit for
Advertising Opportunities

Attention Designers:  Please alert us by eMail if we have linked to sites
where your original material has been copied without your permission.
We will change to the LINK to your site.  
Thank you.


Gadget Circuits
Gadgets:  #'s - C        D - E        G - L        M - O        P - S       
T - Z

Last Updated: October 24, 2017 02:54 PM

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

Circuits Designed by Dave Johnson, P.E. :

Earthquake Alarm CircuitGeophones are dandy motion sensors.  They are metal cans containing a powerful magnet, suspended with springs inside a coil of wire.  The magnet functions as a floating mass.  The slightest vertical motion of the device causes the coil to move relative to . . . Hobby Circuit designed by David Johnson P.E.-July, 2005

Electrical Device Harvests EarthwormsA 120vac or 240vac isolation transformer is used to force earthworms from the ground.. . . Circuit by Dave Johnson P.E.-July, 2006

Earthquake Alarm Circuit -  Geophones are dandy motion sensors.  They are metal cans containing a powerful magnet, suspended with springs inside a coil of wire.  The magnet functions as a floating mass.  The slightest vertical motion of the device causes the coil to move relative to . . . Hobby Circuit designed by David Johnson P.E.-July, 2005

Ed Had a Fondness for Orange Crush -  15-May-06 -Design News:   For the  who thinks he has everything, here's Ed Nauman's microprocessor-controlled, pneumatic-actuated can crusher.  Great for parties, it consists of a pneumatic ram, precision bore crushing cylinder with aluminum crushing piston, two pneumatic rams to control the loading of cans, and __ Gadget Freak-Case #84

Egg Timer -  This circuit sounds a buzzer after a preset time with P1 using a common 555 timer IC.  Excellent to cook your eggs perfectly.  Have fun building or bread-boarding this circuit and don't hesitate to experiment on it! __ Designed by Tony van Roon  VA3AVR

Egg timer, PCB layout & assembly information -  No circuit description, schematic only__ CdS Electronic

Egg Timer -  two 555 timers, a buzzer sounds at the end of the time period, one beeps, the other bleeps! __ Contact: P. Townshend EduTek Ltd

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

'Einstein' Sparks STEM Initiative -  9-Apr-14 -Design News:   Elaine HansenAt Einstein in a Box, we take the statement "inquiring minds want to know" to a whole new level.  We deliver a project-based learning activity in a uniquely designed package to entice children to play while learning through science, technology, math, and engineering  (STEM) .  A product of Academics in __ Gadget Freak

Electric Bug Zapper -  None of us likes bugs at home.  To kill these flying insects, they should first be attracted and then electrocuted.  Bug zapper is one such device with a high-voltage electrocuting circuit...__ Electronics Projects for You

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

Electrical Device Harvests Earthworms -  A 120vac or 240vac isolation transformer is used to force earthworms from the ground.. . . Circuit by Dave Johnson P.E.-July, 2006

Electro-Etching -  An AlternativeCheaper method of Etching PCB'suses much less Ferric Chloride.   __ Designed by G.L. Chemelec

Electroluminescent Wire Sequencer -  Assembly and Operation of the SEQ5 ELWire Sequencer __ Designed by John DuBois

Electromagnetic Ring Launcher -- Building a Science Museum Classic -  21-Nov-16 -Design News:   Sajjad HaidarThe Jumping Ring or Electromagnetic Ring Launcher experiment is a staple of science museums and physics class rooms.  Here's how to build your own right in your home. __ Gadget Freak

Electronic Astrologer -  This electronic astrologer answers in either YES or NO.  For this reason it is a good idea to put this circuit in a box, and mark one LED as YES, and another as NO.  Electronic astrologer can played like this :- You ask such question whose answer can be either YES or NO, e.g Is it going to rain today ?.  Now, press and release push-button (S1) to get the answer.  After release, the glowing LED is electronic astrologer's answer. __ ` Sigmatone

Electronic candle -  This  circuit  will  detect  light  falling  on  the  Light Dependent Resistor  (LDR or CdS) .   When light falls on the  LDR  the  arrangement  of  resistors  at  the  base  of  the transistor T1 gives a change of voltage.   This biases or turns  on  the  transistor  which  turns  on  T2,  allowing sufficient  current  to  flow  to light the globe.   The arrangement of the  resistors at the base of T1 is called a Potential Divider.   It is adjusted to suit ambient light conditions by the variable resistor VR1.   A typical use would be to set the project up in the refrigerator.  The light will light up in another room if you have enough wire, or you  could put  a  buzzer  in  instead  of the light and catch whoever is raiding the refrigerator.__ CdS Electronic

Electronic Candle BLow Out -  LED or bulb switch off with a puff; Funny gadget3V Battery supply __ Contact: Flavio Dellepiane, fladello @ tin.it

Electronic Chime -  Scroll Down to find this circuit.  This circuit simulates a chime similar to the sound many cars make when the keys are left in the ignition.  The bottom two gates form a squarewave audio oscillator that drives the base of the 2N4401, turning it on and off at an audio rate.  The top two gates produce a short low-going pulse about once per second that discharges the 10 uF capacitor through the diode.  The voltage then jumps up and slowly decays __ Contact: Charles Wenzel of Wenzel Associates, Inc.

Electronic Dice -  This electronic dice has no chance of wear and tear but all the features of a wooden or plastic dice used for Ludo game.  The circuit comprises an astable multivibrator built around...__ Electronics Projects for You

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 -  I built this small Dice because we had a spare corner of PCB un-used of a larger PCB design.  Project originally belong to Pete Griffiths and I thank his efforts in making such a nice project and make available code for free use. __ Designed by Nina Gajjar

Electronic Dice -  It is good idea to put this circuit in a box and mark/write each LED with number 1 to 6.  Now, when switch S1 is pushed momentarily, any one of the 6 LEDs will glow.  The Number marked for glowing LED becomes dice's output.  Every time S1 is released, new LED will glow randomly.  Chances for each LED to glow is 16.66%. __ ` Sigmatone

Electronic Dice using AT89c2051 -  This simple circuit demonstrates the capability of an AT89C2051 microcontroller chip to function as a random number generator based on the flying counter principle.  The program in the chip constantly updates...__ Electronics Projects for You

Electronic Dog Whistle -  Need electronic dog whistle? It is widely known that dogs can hear sounds with frequencies higher than the humans cant hear.  Sound frequencies higher than 20 kHz can be hardly detected by humans but animals are very sensitive to it.  Basing this fact, an electronic dog whistle can be constructed and used to call dogs back from __ Designed by D Mohankumar

Electronic Fuse -  An absolute necessity of every electronics lab is a workbench power supply.  The power supply should be regulated and protected against short circuit.  Most power-supply protection circuits use a low-value, high-wattage resistor...__ Electronics Projects for You

Electronic Fuse -  This is adjustable elctronic fuse that can be used to protect power supplies from short circuits or can be also used to limit the current usage.  It can be adjusted for currents from 100mA up to 4.3A.   __ Designed by di Domenico Di Mario

Electronic Fuse -  Full short-circuit and overcurrent protection is given by this circuit suitable for workbench applications in technical schools and laboratories where there is a need to work directly with the mains.   __ Designed by © EFY Enterprises Pvt. Ltd.

Electronic Fuse for DC Short Protection -  This is an electronic fuse that protects the load against short circuit.  Relays must be choosen with a voltage value equals to the input voltage.  Don't omit using the 100uF capacitor with appropriate voltage value with respect to the input voltage.  If you can't provide, you can use C106 instead of BRX46.  You can adjust the current with using 10K potentiometer.  If you will use the fuse with very high currents, lower the 0R6 5W resistor value  (ex.0R47, 0R33, 0R22 or 0R1) .  Watt value of the resistor should be increased also.  

Electronic Games -  Collection of electronic game circuits __ Contact: Charles Wenzel of Wenzel Associates, Inc.

Electronic Heart -  With this electronic heart glowing on and off, you are sure to steal the heart of that special someone.  The circuit uses an NE555 timer wired in astable multivibrator mode.  Its...__ Electronics Projects for You

Electronic Horn -  Here’s a simple circuit of an electronic horn that is built around quadruple op-amp IC LM3900  (IC1) . IC LM3900 has four independent op-amps  (A1 through A4) with a large output voltage...__ Electronics Projects for You

Electronic I Ching -  This circuit is the electronic emulation of the I Ching, a form of divination originating in China.  In the classical form, the response is obtained by the manipulation of 50 sticks or, more practically, by tossing 3 coins.  The process must be repeated 6 times in order to complete what is called an hexagram.  The various combinations given by the 6 readings are then read with the help of a book: the I Ching in fact or book of changes, used as a guide for the interpretation of the results.  As the hexagrams look very much like a binary code, 

Electro-Static AIR Filters -  This article deals with Principals of a Good Electrostatic Filter systemPlus Basic Plans.   With a Schematic for the HV Static Supply and I can Now Supply the Trigger Coil for this.   __ Designed by G.L. Chemelec

Emergency Siren Simulator -  This siren circuit simulates police, fire or other emergency sirens that produce an up and down wail.   __ Contact: Charles Wenzel of Wenzel Associates, Inc.

Enable oscilloscope art -  09/24/13  EDN-Design Ideas Let your inner artist out: Paint electrons in quadrature __ Circuit Design by Lyle Williams

Energy-Harvesting Soccer Ball Gets a Kickstart -  14-Mar-13 -Design News:   Elizabeth MontalbanoA New York-based startup is taking the idea of energy harvesting to a more philanthropic level through the use of something that can be found in nearly every country in the world -- a soccer ball.  The founders of Uncharted Play Inc.  have developed a prototype soccer ball, called SOCCKET, that __ Gadget Freak

ESP8266 WIFI MailBox Email Alert SystE - M -  The ESP8266 wifi serial modules, are the new HIT, so i had to play with them also, Here is my second project with this new-wounder, a wireless WIFI enabled mail box with email alert, a very usefull tool for my busy day :-)  So now there is no need to look into the mail box and see it is only empty. __ Designed by Thomas Scherrer OZ2CPU

Eurotech's Mirror Is Smarter Than Your Mirror -  23-Jun-15 -Design News:   Hilary Tomasson of Eurotech Inc.  , explains how the company's network gateway can be applied to a smart mirror that displays personal calendars, weather information, new feeds, or other information.  Eurotech showed off the mirror at the Freescale Technology Forum, which is taking place this week in __ Video-Gadget Freak

Evil Scientist or Rocket Science? You Decide -  6-Feb-06 -Design News:   What could be cooler than launching model rockets? Launching a lot of them! To control multiple rocket launches relative to one another and put on an utterly amazing backyard air show, Joe designed a circuit  (replicated for each rocket) consisting of two 555 timers configured for monostable __ Gadget Freak

Exploding Confetti Cannon -  Here is a cool pyrotechnics gadget that explodes with a shower of confetti! Great for live concerts, parties, weddings, special events.  you name it! What You Need A glow-plug which you can get HERE Electrical Box with cover Plumbing Extension __ Designed by Radio LocMan

   <<<         This is the last page of DF

Gadgets:  #'s - C        D - E        G - L        M - O        P - S        T - Z


Imagineering Ezine    Discover Solar Energy Dave Johnson & Associates Faraday Touch Switches

 About Us   |  Advertise on DiscoverCircuits.com   |   Report Broken Links  |    Link to DiscoverCircuits.com  |   
Privacy Policy

Discovercircuits.com endeavors to credit original designers.   Please alert us by eMail so we can
delete links to material that have been copied without your permission
.   Thank you.

© Copyright of all original material on this website is the property
of David A. Johnson, P.E. (Dave Johnson & Associates ) unless otherwise noted.  

Linking is ALLOWED but COPYING any content or graphics to your web site is EXPRESSLY PROHIBITED.
All material is provided "as is" without guarantees or warranty of any kind, either expressed or implied.