My first circuit is a fun and easy to assemble Do it Yourself kit. It combines some of the most common electronic components (such as LEDs, resistors, capacitors, transistors etc.) with others that are rather interesting like the photo-resistor.


From a functional point of view it is a so-called joule thief or vampire torch that only actives in the dark. Specifically, LEDs need 3V to light up but the circuit is powered using only a 1.5V battery. However, when the photo-resistor detects low levels of light intensity the LEDs light up. How is that possible? The circuit has a voltage booster area that increases the voltage to nearly 6V so that it can power both LEDs in series. It does it through an oscillatory behaviour that fills the capacitor with voltage. Further, when the capacitor is charged the transistor comes into play as it releases all the voltage to the LEDs all at once. This process is iterated until the battery is fully discharged. This also means that the lights are not on all the time, but it all happens so fast that it is not visible to the naked eye.


The kit can use nearly all of the energy in a single-cell electric battery, even far below the voltage where other circuits consider the battery fully discharged (or "dead").

May 29,2019
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    • Omer Faruk Ucar from TURKEY
      Founder of the project ‘Lezzetli Robot Tarifleri’ In the frame of this project he produces Turkish contents about electronics/software and serves it to people for free. He produced many jammer devices mostly drone dropper weapons while working in electronic defense industry. He gave lessons to teachers about software and electronics in a program which supported by the government. And now he is working as a hardware engineer on SCADA systems syber security.
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    • Ilya Galkin from RUSSIAN FEDERATION, THE
      Senior hardware engineer
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    • Catia Diaz from MEXICO
      Catia Diaz director of YouTube channel catykanal that was created to insentiate the taste for electronics with tutorials explained in a simple and fun way. Teacher with more than 3 years of experience in promoting the learning of electronics to children and young people.
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    • Engineer from TURKEY
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    • Jiri Praus from CZECH REPUBLIC, THE
      If you got a low score from me, I don't think you fit for I can solder content. Sorry for that, at least I tried to rate your design. I am an artist. I design electronics and brass wire sculptures. www.jiripraus.cz
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    • Oyvind Dahl from NORWAY
      NOTE: If you have a project that I don't think is for beginners (or I don't understand what it is/lacks documentation) - you'll automatically get a low score from me even though your project is really cool. Sorry! ABOUT: Author of Electronics For Kids. Creator of Ohmify.com and the electronics blog build-electronic-circuits.com.
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    • Ever since I was a kid, I love tinkering with anything that involves energy from toys to cellphones. I love designing and creating projects that could be innovative with the use of electronics. I was also appointed team leader of the University of Sto. Tomas team for the Shell Eco-marathon Philippines Competition in 2018.
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    • J_RPM from SPAIN
      My name is José Ramón Pueyo, I live in Spain. For more than 40 years he has worked in the radio communication sector, mainly with RF equipment and developing control and monitoring systems.Five years ago I opened a channel on YouTube (J_RPM) in order to share some developments and divulge technical information.
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    • www.cursoderobotica.com
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