Transistor clarification

[MrHeckles]

Could someone please clarify what emitter-base voltage is on a transistor for me.

Could I, for example, have a transistor with a Veb of 6v with the base of the transistor connected to a 12v source (assuming the collector-emitter side was also connected to the same 12v source)?

What about the same transistor with 12v on the base and 18v on the collector-emitter side.

Thanks in advance for clearing up my confusion.

 

[audioguru2]

Hi Mr. Heckles,
You should read about transistors in our Articles section.

The base-emitter junction of a junction transistor is a silicon diode!
A small transistor has about 0.7V across it at a few mA of collector current but it changes a little with changes in temperature and current.

You are talking about Veb instead of Vbe, so maybe you are thinking about a Jfet which has a negative voltage on its gate.

The base-emitter junction of a junction transistor is usually used forward-biased with about 0.7V across it, but its datasheet rates an absolute max reverse voltage rating of 5V to 7V when it has avalanche breakdown, which maybe you are confused about. :

View attachment 38015

 

[MrHeckles]

Thank you audioguru.

I was getting confused about the reverse breakdown voltage. That clears up my misunderstanding nicely.