Search Results for: Radio broadcast receivers without an external power source
annular blowout preventer is a large valve that uses a wedge to seal off a wellhead. it has a donut-like rubber seal, known as an elastomeric packing unit, reinforced with steel ribs. during drilling or well interventions, the valve may be closed if overpressure from an underground zone causes formation
can be much larger than the controlling input power, the transistor provides amplification of a signal. the transistor is the fundamental building block of all modern electronic devices, and is used in radio, telephone, computer, and other electronic systems. from november , to december , , john bardeen...
https://en.wikipedia.org/wiki/Timeline_of_United_States_inventions_(1946%E2%80%931991)