Oooh, I get it now. VBE is the potential difference between the emitter and the base. Decreasing it will reduce the base current. I was viewing that VBE as the 0,7V potential barrier but it was just the difference between VB and VE :D Thank you, kind sir!LvW said:Rewriting your equation we have
VBE=VB-VE.
As you wrote - in case of constant VB (resistive voltage divider) an increase of VE (larger emitter current IE) will reduce the difference (VB-VE).
This reduction in VBE is the desired negative feedback effect.
The problem is that the IC=f(VBE) exponential relation is very sensitive to temperature changes (-2mV/K). Hence, for a constant VBE the current IC would change its value - more than allowed. For this reason we are using such an emitter resistor RE which produces an increasing voltage drop VE=IE*RE for the unwanted current increase. As a result, the voltage VBE again will decrease and, thus, bring back the current IE (and withit: IC) to nearly the previous value.
VBE stands for "voltage between base and emitter" and refers to the voltage difference between the base and emitter terminals of an NPN transistor. It is an important factor in determining the behavior and characteristics of the transistor.
VBE plays a critical role in determining the base current, which in turn controls the collector current in an NPN transistor. The value of VBE also affects the amplification and switching capabilities of the transistor.
VBE and VE both refer to voltage differences in an NPN transistor, but they are measured in different ways. VBE is measured between the base and emitter terminals, while VE is measured between the emitter and ground. VE can also be referred to as VCE, or "voltage between collector and emitter."
VBE is directly related to the base-emitter junction of an NPN transistor. This junction acts like a diode, and the voltage drop across it is known as the "junction voltage" or VBE. The value of VBE is determined by the type of transistor and the current flowing through it.
No, VB and VBE cannot be used interchangeably in an NPN transistor. VB refers to the voltage between the base and a reference point, which is typically ground. VBE, on the other hand, specifically refers to the voltage between the base and emitter terminals of the transistor. These values may be different depending on the circuit configuration.