Professor Hawking used an input device controlled by his cheek movements to choose the words he wanted to use. A special output device turned those words into electronic speech that people could hear.

Internal operating voltages in electronic devices continue to decrease, but input-source voltages don't change. As the difference between input and output voltages increases, so does the improvement ...

In essence, it boosts weak dc signals with an output potential that can be 100,000X larger than the potential difference between input terminals ... between sensors and devices such as analog ...

A crucial measured characteristic is the transfer function, which details the static relationship between device input(s) and output(s) and allows prediction of the equilibrium behavior of ...