13 basic transistor application
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Transcript of 13 basic transistor application
University of Bahrain
Electronic Circuits I ITCE263
Dr. Mohammed Majid Al Khalidy
Lesson 13
Basic Transistor Application
Dr. Mohammed Majid al Khalidy
The transistor in the circuit is switched between cutoff and saturation.
An npn bipolar inverter circuit used as a switch
If vI < VBE (on), then iB = iC = 0 and the transistor is cut off. If the load were a motor, the motor would be off with zero current.
If vI = VCC and if the ratio of RB to RC , where RC is the effective resistance of the load, is less than β, then the transistor is usually driven into saturation.
Dr. Mohammed Majid al Khalidy
which means that:
In this case, a collector current is induced that would turn on the motor or the LED, depending on the type of load.
Dr. Mohammed Majid al Khalidy
Calculate the appropriate resistance values and transistor power dissipation for the two inverter switching configurations shown in the Figure below.
Example
below
Solution:
Dr. Mohammed Majid al Khalidy
Determine the currents and voltages in the circuit shown in Figure below.
Example
Solution:
Dr. Mohammed Majid al Khalidy
The bipolar inverter circuit can also be used to amplify a time-varying signal