BJT Homework Help: Troubleshooting Results

In summary, The speaker is discussing the results of a lab and questioning the accuracy of the results. They mention strange results when trying to find I(c), I(b), and I(e) and speculate about the linear region and small dc gain. They also question why I(b) is negative in one combination and whether R2 is acting as a battery. The listener suggests an alternative method for determining the value of IB.
  • #1
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This is the result from a lab,but I am not sure the results are correct.
Also,when I try to find I(c) , I(b) and I(e),by measured V(RC) and V(RE),I find the results strange.
I guess the combination of R1=10k and R2=10k is under linear region,but the dc gain is so small.
For combination of R1=10k and R2=1k,Idon't know why the I(b) is negative.Is it the cut off mode?
And for combination of R1=1k and R2=10k,it should be in saturation?
I guess R2 is like a battery so current I(b) flow ,but how about R1??
 

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  • #2
You calculated IB using IE - IC. This can be inaccurate when IE is close in value to IC.
There is another way you can determine the value of IB in each test situation, it's a more accurate method, too.

What is this second method I speak of?
 

1. What is a BJT and why is it important in electronics?

A BJT, or bipolar junction transistor, is a type of semiconductor device commonly used in electronic circuits. It is important because it allows for the amplification and switching of electrical signals, making it a fundamental component in many electronic systems.

2. How do I troubleshoot BJT circuit results?

Some common steps for troubleshooting BJT circuit results include checking for loose connections, ensuring proper biasing and component values, and using a multimeter to measure voltages and currents at different points in the circuit.

3. What are some common issues that can arise when working with BJTs?

Some common issues with BJTs include thermal runaway, saturation, and breakdown. These can be caused by factors such as excessive heat, high currents, or incorrect biasing.

4. How can I improve the performance of a BJT circuit?

Some ways to improve BJT circuit performance include using proper biasing techniques, selecting appropriate component values, and implementing temperature compensation methods.

5. Are there any safety precautions I should take when working with BJTs?

Yes, it is important to follow safety precautions when working with BJTs, as they can become damaged or even pose a risk of electric shock if not handled properly. This includes using proper equipment, disconnecting power sources before handling BJTs, and being aware of potential hazards such as high voltages and excessive heat.

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