Out of 4 wires in a USB Cable, two wires are for Data transfer and two wires are for Power supply. These two power supply wires in USB cable can be easily identified, generally two extreme side wires or Red & Black wires are used for Power supply.

This simple transistor based water level indicator circuit is very useful to indicate the water levels in a tank. Whenever tank gets filled, we get alerts on particular levels. Here we have created 4 levels (low, medium, high and full), we can create alarms for more levels.

This Instructable is the project I built with a schematic from the IC datasheet and some parts I removed from an old CB radio. Before I call the project completed, I need to add a heat-sink to the amplifier IC and some vent holes in my project box. But as it is right now the amplifier works and sounds great.

Object counters or product counters are important applications used in industries, shopping malls, etc. They count objects or products automatically and so reduce human efforts. In this tutorial we are going to design a simple object counter circuit without using any microcontroller.

IC CD4017 is a CMOS decade counter IC. It can produce output at the 10 pins sequentially, i.e. it produce output one by one at the 10 output pins. Explore below some interesting electronic circuits based on IC CD4017.