Photodiodes and phototransistors are semiconductor devices which have their p-n semiconductor junction exposed to light through a transparent cover, so that external light can react and force an electrical conduction through the junction. How Photodiodes Work A photodiode is just like a regular semiconductor diode (example 1N4148) consisting of a p-n junction, but it has […]
Circuits
Build Simple Transistor Circuits
A compilation of important assorted transistor simple circuits to build has been included here. Simple Transistor Circuits for New Hobbyists Many simple transistor configurations like, rain alarm, delay timer, set reset latch, crystal tester, light sensitive switch and many more have been discussed in this article. In this compilation of simple transistor circuits (schematics) you […]
9 Simple Metal Detector Circuits Explained
In this post I have explained 9 simple metal detector circuits using LC tuned concept, magnetic absorption concept, and the beat frequency oscillator (BFO) concept. The BFO technique is considered to be the most accurate and reliable methods of detecting metals. 1) Metal Detector Circuit Using a Single UJT The first metal detector circuit shown […]
4 Simple VU Meter Circuits Explained
In this post I have explained how to build 4 interesting VU meter circuits, using LEDs and using a moving coil meter. What is a VU Meter VU meter or a volume unit meter circuit is a device used for indicating the music volume output from an amplifier or a loudspeaker system. It may be […]
Designing Simple Power Supply Circuits
In this post I have explained how to design and build a simple power supply circuit right from the basic design to the reasonably sophisticated power supply having extended features. Power Supply is Indispensable Whether it’s an electronic noob or an expert engineer, all require this indispensable piece of equipment called the power supply unit. This is because no electronics […]
5 Simple Audio Mixer Circuits Explained
The explained 5 circuits below are universal simple audio mixer circuits, that may be customized and upgraded to 5 channel or even 10 channel mixers, as desired by the user. Contributed by: Anil Rao. Stereo Audio Mixer The operation stereo audio mixer circuit shown below is straightforward: If a mic is “being used,” its output […]