例句與造句

1. Unlike the beat frequency oscillator or the induction balance machines which both used a uniform alternating current at a low frequency, the pulse induction machine simply magnetized the ground with a relatively powerful, momentary current through a search coil.
2. In 1879 the experimenter and inventor David Edward Hughes working in London discovered that a bad contact in a Bell telephone he was using in his experiments seemed to be sparking when he worked on a nearby induction balance ( an early form of metal detector ).
3. He developed an improved detector to pick up this unknown " extra current " based on his new microphone design ( similar to later detectors known as coherers or crystal detectors ) and developed a way to interrupt his induction balance to produce a series of sparks.
4. It's difficult to find induction balance in a sentence. 用induction balance造句挺難的