All Questions
12
questions
0
votes
1
answer
403
views
Fermi levels in PN-junction under forward bias are not constant throughout each side
This is, in a way, a follow-up to this question.
I see the following band diagram for a forward biased diode everywhere:
In the above picture, I marked a point with potential zero (where battery is ...
- 163
16
votes
5
answers
4k
views
Resistance depending on voltage - the chicken and the egg?
If I understand correctly:
The resistance of some circuit components (like diodes) depends on the voltage across them.
When two components are connected in series: \$\frac{V1}{V2} = \frac{R1}{R2}\$
...
- 181
2
votes
1
answer
993
views
What is the exact meaning of 0.7V voltage drop in a forward-biased diode?
this question is partially (but not totally) discussed here:
Why do diodes have a voltage drop?
Does the power drop on a diode become entirely heat?
The conclusion is that, in a forward-biased diode ...
- 3,550
-1
votes
1
answer
199
views
What happens when an LED burns out? [duplicate]
When an LED is burned out, specifically which part is burned out?
Is it the semiconductor or the wires?
Can we use a burned out LED to generate electricity?
0
votes
0
answers
267
views
Simulating circuit TINA TI
For my assignment I got to run a transient analysis for the duration of 5 periods of sinusoidal input voltage and display the input voltage (ac + dc) and the output voltage on the RL component.
Used ...
- 1
0
votes
2
answers
262
views
Forward voltage across the diode
If the diode's dynamic resistance was zero , will not we be able to increase the voltage across the diode above 0.7 v ?
(I am assuming forward bias )
I am asking this question because my book ( ...
- 37
1
vote
2
answers
122
views
Designing a circuit that opens when less than 12 volts are applied and closes when more than 12 are applied
I'm looking to build a circuit where current only flows when there is a potential difference across the entire circuit of more than 12 volts (+- 0.1 V). I also need there to be only a small amount of ...
- 203
1
vote
4
answers
493
views
Is forward biasing or reverse biasing an inherent property of a diode?
I read a tutorial about transistors and I reached the following sentence.
"The Bipolar Junction Transistor (BJT) is a three layer device constructed form two semiconductor diode junctions joined ...
- 803
4
votes
1
answer
5k
views
Measuring barrier potential of a pn junction using a voltmeter
The image above is from the book "The Electronics companion". Can someone please explain why the barrier potential of a pn junction cannot be measured due to the presence of the contact potential?
- 253
3
votes
3
answers
1k
views
LED typical and forward voltages
So, I was going through the spec sheet of super bright 5mm orange LED, and it was listed that the forward voltage is between 1.8V and 2.5V. Below that there was a property listed as 'typical voltage' ...
- 187
0
votes
1
answer
3k
views
Cutoff and Conducting diodes
Why is D1 considered cutoff and D2 considered conducting ?
Note : I am working with constant voltage model where the diode voltage is 0.7v and I need to figure out I and V. Please explain why D1 is ...
- 178
45
votes
8
answers
11k
views
Why isn't there a potential difference across a disconnected diode?
I know this question sounds silly, as if there was a potential difference a current would be created when the terminals are connected together and this would mean energy has come from somewhere.
The ...
- 1,655