NPN Emitter Follower Switch: Design Procedure?

[blackshadow]

can anyone itemize the process of biasing an NPN emitter follower to act as s switch?

 

[ericgibbs]

can anyone itemize the process of biasing an NPN emitter follower to act as s switch?

hi,
As a general rule.
Knowing the collector current you are switching, set the transistor base current to be approx 10% of the collector current.

This assumes a transistor gain of 10 when in Vce Sat.

OK.?

Edit:
Incorrectly read the OP post as common emitter.!

 

[dougy83]

For emitter-follower, no bias is used - for NPN, the collector goes to a positive supply, the emitter to the load and the base to the control signal. Have a look at: Common collector - Wikipedia, the free encyclopedia