What is it?

My first circuit is a fun and easy to assemble Do it Yourself kit that does not require soldering. 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.

Why did you make it?

I am keen on building my own Electronics since this enables me to understand how things work as well as get to tailor them according to my own needs. Therefore I encourage learning by doing as a means of discovery and acquisition of both knowledge and skills. And what better way to understand how electronic components really work in a circuit than by building your very first circuit.

What makes it special?

One of the main reasons why building electronics seems cumbersome for beginners is the fact that it requires not only knowledge and skills, but also buying a lot of hardware and tools. Therefore, My first circuit is a plug-and-play electronics kit that enables experimentation without soldering.

Another reason why the kit is special is the fact that it 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").

And, of course, it can serve you as a night-light.

What’s in the kit

• 1 x PCB
• 1 x Plexiglass cover
• 1 x AA battery holder
• 4 x LEDs
• 2 x Potentiometer (50k)
• 2 x Photoresistor (3k-0.3M𝛺)
• 2 x Capacitor (22pF)
• 2 x Resistor (1k)
• 2 x Resistor (10k)
• 2 x Resistor (100k)
• 2 x Inductor(470uH)
• 4 x Transistors (NPN - MPSA06)
• 2 x Transistors (PNP - 2N3906)
• Screws and screwed spacer sleeves

What’s needed

An AA battery (even slightly used). That and curiosity. Just Go hard!