By convention, there are actually two different base voltages that are chosen, V and V which are equal to the rated voltages for either side of the transformer.
22.
When the input voltage ( Q1 base voltage ) rises slightly above the voltage across the emitter resistor R E ( the high threshold ), Q1 begins conducting.
23.
When the voltage of C1 right-hand plate ( Q2 base voltage ) becomes positive and reaches 0.6 V, Q2 base-emitter junction begins diverting a part of R2 charging current.
24.
The output voltage is about 0.65V less than the base voltage, which in turn is about 2 & ndash; 3 V less than V S ( when loaded ).
25.
There is a full ( 100 % ) negative feedback; the two input base voltages and the emitter voltage change simultaneously while the collector currents and the total current do not change.
26.
He designed a DXing radio receiver when he was 14, which never worked; however, he designed his own SMPS based voltage regulator for the genset, after which it was accepted by the army.
27.
If the input current is increased, then the collector voltage falls below the base voltage, and the Shottky diode starts to conduct and shunt some of the base drive current into the collector.
28.
An increase in the collector base voltage, for example, causes a greater reverse bias across the collector base junction, increasing the collector base depletion region width, and decreasing the width of the base.
29.
As it exceeds the voltage required to bias the emitter-base junction of Q3, Q3 acts as an emitter follower or common collector amplifier and the base voltage of Q1 and Q2 begins to rise.
30.
However, even with a fixed base voltage, collector current varies with temperature ( for example ) so an emitter resistor is added to stabilize the Q-point, similar to the above circuits with emitter resistor.
