Jake Peterson is Lifehacker’s Tech Editor, and has been covering tech news and how-tos for nearly a decade. His team covers all things technology, including AI, smartphones, computers, game consoles, ...

Here this circuit is based on the principle of audio amplification using operational amplifier and pulse width modulation using 555 Timer. In this article we are describing the principle, design and ...

We may earn commission from links on this page, but we only recommend products we love. Promise. Ahead, check out the best sleep sound machines your $$$ can buy, including travel-friendly models, ...