Comparison with vacuum tubes:
Prior to the growth of transistors, vacuum (electron) tubes (or in the UK (United Kingdom) "thermionic valves" or just "valves") were the major active components in electronic equipment.
Advantages:
The main advantages that have permitted transistors to replace their vacuum tube predecessors in several applications are
- Small size and minimal weight that permitting the development of miniaturized electronic devices.
- Highly automated manufacturing processes that resultant in low per-unit cost.
- Lower possible operating voltages, creating transistors appropriate for small, battery-powered applications.
- No warm-up period for cathode heaters needed after power application.
- Lower power dissipation and usually greater energy efficiency.
- Higher reliability and bigger physical ruggedness.
- Very long life. Some transistorized devices have been in service for much more than 50 years.
- Complementary devices available that facilitating the design of complementary-symmetry circuits, something not possible with vacuum tubes.
- Insensitivity to mechanical shock and vibration so avoiding the problem of microphonics in audio applications.