A sealed glass tube containing a near-vacuum which allows the free passage of electric current.
- ‘We think of the 1950s as the golden era of the vacuum tube.’
- ‘I didn't know much about transistors because my education was during the days of vacuum tube.’
- ‘In 1948 the vacuum tube was replaced by longer-lived solid-state transistors, marking the dawn of microelectronics.’
- ‘It wasn't until the vacuum tube and the transistor were invented that true computers became feasible.’
- ‘A photocell is usually a vacuum tube with two electrodes.’