Is it to prevent loadin? What exactly is loading
2007-03-12 18:23:21 · 4 answers · asked by Reni 3 in Science & Mathematics ➔ Engineering
The base emitter junction is a diode. If you inject a voltage into the emitter it is only one diode drop above ground. The resistor is a current limiter to protect the emitter and the driver.
2007-03-12 18:42:27 · answer #1 · answered by John S 6 · 0⤊ 0⤋
You need an input resistor if you don't have an emitter resistor, to limit base to emitter current. Yes, it is to prevent a loading effect of the base-emitter. Loading is the effect of a power source supplying current.
2007-03-13 12:43:55 · answer #2 · answered by joshnya68 4 · 0⤊ 0⤋
resistor is needed to prevent high flow of input current.... otherwise the transistor will go into saturation region...
2007-03-13 05:14:53 · answer #3 · answered by the_phenom 1 · 0⤊ 0⤋
see:
http://en.wikipedia.org/wiki/Common_emitter
The emitter resistance provides negative feedback, therefore, trading some gain for stability
2007-03-13 02:12:27 · answer #4 · answered by arbiter007 6 · 0⤊ 0⤋