A type of indicator circuit for batteries

I am thoroughly impressed with the Elecrow 5-Inch QLED Quantum Dot Display. I tested it with several devices, including the Homatics Pocket TV, Goovis D4-H1 4K Portable Stream Media Player, Firefly Station P1 Geek Mini PC and my Oppo Find X5 smartphone, and the video output consistently delivered smooth performance with exceptional visual clarity. For connectivity, I utilized HDMI-to-HDMI and USB Type-C-to-HDMI cables, which ensured seamless operation across all devices.

This device is a simple square wave oscillator kit. The frequency range is from 1.5296 Hz to 15,000 kHz.

Famous Actidamp Mk2 phono preamp construction excellent in audio quality, redesigned for modern parts.

The project represents an electronic switch actuated by the value of the light intensity that excites a photoresistor.

Simple electronic circuit.

This is a relatively cheap complete Tesla coil driver, so we only need a primary and secondary coil to build functional Tesla coil.

A simple way to build a quality multiband receiver using a specialized radio chip.

Another electronic project.

A balance indicator for audio systems.

The Pinecil LED Ring adds three LED lights to the Pinecil soldering iron to improve soldering in dark environments. This addition to the Pinecil soldering iron fits just above the soldering tip on the plastic area by friction so no glueing is required. It is easy to assemble and add to the iron using another soldering iron to connect the internals.

These miniature metal detectors cannot boast of any great sensitivity, but it would still be good to make them for any enthusiast in this field, especially because of the opportunity to study in detail the way such devices work.

This is a light bulb indicator kit that blinks with music.

Using this electronic circuit, a very simple pulse generator can be made, using a 4066 circuit.