Hi all
If I connect the base ( of photo transistor ) by a resistor to the emitter, and I expouse the transistor to light, wiil any current (due to light effect) will flow through
the resistor ?
How to calculate that current?
Hope the answer will not contain physics.
BR
Sure. Transistor base current is supplied from light source. But, some of the current will flow through resistor. Base-emitter voltage is approximately ~0.7V. So, you can calculate the current: IR=0.7/R
If you connect a resistor between the base and the emitter of a phototransistor,
you are lowering the BE impedance, hence doing the transistor less sensitive to
the light incidence. In some cases this is a common practice to decrease the gain.