Solving Diode Circuits | Basic Electronics

If you want more videos on basic electronics, subscribe to the CircuitBread channel!

Table of Contents:
0:00 Introduction
0:14 What is the quiescent point, or the q-point, of a diode?
0:36 Load Line Analysis for solving circuits with diodes in them
1:15 Math model for diode circuit
2:18 Ideal diode circuit analysis with the four steps
8:39 Constant voltage drop diode example
14:15 Review of the four methods and four steps

CircuitBread is joining the fight to help people more easily learn about and use electronics. With an ever-growing array of equations, tools, and tutorials, we're striving for the best ways to make electronics and electrical engineering topics more accessible to everyone.

Connect with CircuitBread:

[yarenkaya]

Finally, a systematic solution with checkpoints! Thank you very much for the tutorial.

[MERF]

You went to BSU?! Me too! Who was your microelectronics teacher? I had Dr Campbell she is my favorite professor! Nice to meet another alumn!

[tjriz]

I have a question. We are learning about diode circuits right now in my microelectronics class. One of our homework problems has us solving for the diode voltage and current of a diode/resistor series circuit using not only the constant voltage diode model, but also the iteration method using both the KVL equation and the exponential diode equation, along with finally a load line analysis using Python/MatLab. We are tasked with solving for these values with the applied voltages of 0.5, 0.8, 1, and 1.2 V. The values of reverse saturation current and resistance are both given. Using the iteration method for the applied voltages of 0.5 and 0.8V, the resulting values of diode voltage quickly rise above the amount of applied voltage, which obviously doesn't make sense in reality. And subsequent iterations would result in a negative current, which causes issues for the log function being used for the iteration. I know this is surely because it is before the threshold voltage that would cause current to flow. I feel comfortable in saying that no current would be flowing with the applied voltages of 0.5 and 0.8 V, but what exactly could I say about the diode voltage when the iteration breaks down?

[mehdicharife]

Why in 11:47 do you assume that there is no voltage drop across the 22k resistance ?

[adizafran]

hey, thanks for the great explanations! I was wondering in the last exercise of i2=0 how does the voltage drops across D2?

[Deus]

Feeling like my professor threw our class to the wolves, on the same day he introduced diodes he wants us solving the peak forward current through them and we have both AC and DC sources in the circuits. Any chance you have an example like that?

[derekmitt]

I think you are using conventional flow theory and not electron flow theory. Is this correct?

[kritisohagchakma]

I am confused about i1, i2 and i3 of the first math..can you please explain?

[dominikbaricak]

Why it's not closed circuit? This is terrible method of circuit drawing

[chrisoca]

You are amazing!!! I subscribed!! Thank you very much!

[caliskanata]

complaining about your sketch ? you don't wanna see how i draw an inductor

[znhait]

I think drawing circuits in such a manner is confusing. Circuits are supposed to be closed and putting voltages at a node with no connection in sight throws people off.

[BorselinoThadchack]

you should have done it in Circuit LAb

[Mehedi_buet_]

thank you..helpful..and you speak so nicely😊

[latitude]

5:55 Why does I1 current split to make I2 and I3. Is it because voltage higher on anode for diode 2.

[TKR]

dang ! you have your own microscope for soldering ? nice. You have a nice man-cave setup!

[krTX]

In the last 2 examples:-
You took 0.7 V drop in the forward biased diode in last example.
Whereas,
You didn't took 0.7 V drop in the forward biased diodes in the second last example.
Why so? kindly explain please.

[hannahadams]

Do you have any videos on how to make your forward/reverse bias assumptions? I believe this is what I struggle most with.
Thank you.

[dragontamer]

This is really helpful in understanding diodes and their calculations for an exam I have coming up. Just one question. How do you know if your assumptions are wrong? Are you double checking the current values you got at the end to the assumptions you made for if the diode is forward bias or reverse bias? Forward = current and Reverse = no current.

[quincejohnsjr.]

how was it 409ma when you already converted ma to amps