Hello,
Today I have been experimenting with emitter bias feedback method for biasing a transistor. Please locate in the following link:
http://www.allaboutcircuits.com/vol_3/chpt_4/10.html
where it describes the 1st attempt of calculations as:
β = 100 and Ic = 1.01ma
and
β = 300 and Ic = 2.76ma
in the "emitter bias" section.
When I redid the circuit and calculated it with the real values as shown in T1-EBF-A.png attachment, the measured Ie (1.875ma) was not equal to the calculated Ie (1.54ma)?
Therefore I thought of recalculating it while applying REE calculations. As you can see at attachment T1-EBF-B.png, the calculations resulted as being further erroneous at 1.01 ma???
In summary, the calculations are somewhat close but still off from the actual measurements. Please note, that in my schematic I made VBB the same source as VCC.
Does anyone see where I went wrong?
Any help / feedback is still very appreciated!
Thank you!
regards
r
Today I have been experimenting with emitter bias feedback method for biasing a transistor. Please locate in the following link:
http://www.allaboutcircuits.com/vol_3/chpt_4/10.html
where it describes the 1st attempt of calculations as:
β = 100 and Ic = 1.01ma
and
β = 300 and Ic = 2.76ma
in the "emitter bias" section.
When I redid the circuit and calculated it with the real values as shown in T1-EBF-A.png attachment, the measured Ie (1.875ma) was not equal to the calculated Ie (1.54ma)?
Therefore I thought of recalculating it while applying REE calculations. As you can see at attachment T1-EBF-B.png, the calculations resulted as being further erroneous at 1.01 ma???
In summary, the calculations are somewhat close but still off from the actual measurements. Please note, that in my schematic I made VBB the same source as VCC.
Does anyone see where I went wrong?
Any help / feedback is still very appreciated!
Thank you!
regards
r
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