What Transistor was used befor BJTs(Bipolar Junction Transistor) ?

Question

What Transistor was used befor BJTs(Bipolar Junction Transistor) ?

Answer 1

BJTs were among the first good transistors ever used. Here's a brief history of what came before 1947-48 when the BJTs were first invented.

http://en.wikipedia.org/wiki/Transistor#...

Answer 2

The first transistors were point contact type.

Then came the grown junction transistor, a lot more rugged and practical than the point contact type.

Then came alloy junction or diffused junction transistors (Philco and Sprague)

Finally the modern planar junction transistor.

.

Answer 3

AS we the transistor works as a switch.

the transistor was firstly invented in the late fiftys and the transistor to be firstly made is the bjt.

Vacuum tubes were used before using the bjt.....