About Germanium & Silicon diodes, their voltage drop (0.26 - 0.8 V) & much more, demo + schematics

Please read the description first.

A few days ago I uploaded a video about Silicon and Germanium diodes, but I removed it the following day, because I did not find it good/informative enough.

But I got a request from one of my followers, Gary Granato, where he asked: why did you remove it? It was interesting and I am (we are) interested.

So I made this new video today (7 October 2023) and now (to my own idea) I have explained and demonstrated these subjects much better: Germanium and Silicium/Silicon diodes + a simple test on their forward voltages + a demo about their practical uses in radio or electronic circuits.

Anyway: I think that everything that I wanted to tell is now in this new video.

The scientific information about diodes and the “diode effect” (rectification effect, thus that the current through a material or a stack of materials only wants to flow properly in one direction, thus only from (+) to (-) and not or problematic/cumbersome from (-) to (+) is extremely interesting.

It happens not only in solid materials/with stacks of materials (under certain conditions), but also e.g. with pieces of different metals, immersed in an electrolyte (a certain fluid with sometimes a chemical substance dissolved).

We can remember the AC to DC rectifier circuits for tubes made with different metal plates (I found: lead-aluminum) placed into a watery electrolyte, out of the 1920's. What happens here is, in physical/chemical terms extremely interesting. Charged particles & ions play roles. Ions in wet situations, charged particles in cases of solids. Both are charged particles, by the way.

In solids we are often looking into their (materials, metals, semi-metals) so called “valence bands” and into the quantum mechanic properties of these substances.

Yesterday I read an article in the “Philips Technical Magazine” of 1939 (!) where the effects of semiconduction/semiconducting materials/semiconductor properties related to the physical/chemical crystal lattices of different materials, stapled upon each other, were extensively explained.

Thus (this all) before the invention of the transistor by the dr. (s) Bardeen, Brattain and Shockley in 1947.

Their invention was/must have been “hanging in the air” in the scientific communities (Europe-America- etc.) of those days, the late 1930’s.

When you search, search always “NEWEST FIRST” to get the right overview.

You can also search via the “looking glass” on my Channel trailer via keywords like ”audio”, “radio”, “amplifier”, “filter”, “Shortwave”, “transistor”, “FET”, “oscillator”, “generator”, “switch”, “schmitt trigger” etc; so the electronic subject you are interested in.

My books about electronics & analog radio technology are available via the website of "LULU”, search for author “Ko Tilman” there.

I keep all my YT videos constant actual, so the original video’s with the most recent information are always on YouTube. Search there, and avoid my circuits that are republished, re-arranged, re-edited on other websites, giving not probable re-wiring, etc. Some persons try to find gold via my circuits. I take distance from all these fake claims. I cannot help that these things happen. Upload 7 October 2023.

RELEVANT VIDEO’S regarding the use of diodes, for more info
Silicon diode used as temp sensor to activate a cooling fan, 1 Aug. 2022

And:

Germanium transistor (its diodes inside) used as a temperature sensor to switch an electric circuit in or out (24 April 2023)

About the fore-mentioned (in this text/video) “semiconductor effects” of materials, published in the 1939 Philips Technical Magazine:
Title: “Blocking Layer Rectifiers” by W. Ch. Van Geel, Philips Technical Magazine indication nr. 621.314.63. On Page 100-105 of that 1939 magazine, volume 4.

[acestudioscouk-Ace-GACE]

Thanks very much for this video, I both enjoyed and learnt from it. I'm sure there are many like me who are late comers to electronics and radio who need your "teaching beginners" style. Thank-you.

[samlowe]

i made this 20 years old, but only 1 diode, so it's in class C, but the sound very good for my ear!

[RobertGlotzbach]

Geweldig dat ik dit kanaal heb ontdekt :-) Toen ik jong was, was ik vaak bezig met elektronica, natuurlijk is alles wat ik wist nu weg gezakt. Ik probeer mijn Dynaco 120 versterker te repareren. Ik heb al 4 diodes van de brug gelijkrichter vervangen omdat ze stuk waren. Nu heb ik ook nog het volgende nodig: silicon diode 0.8 volt drop @ 140 ma en een zener diode, 5.1 volt, 5%, 400 mw. Vroeger hadden we Radio Rotor hier in Amsterdam, maar helaas is die verdwenen. Heeft u een suggestie waar ik die diodes kan vinden online, ik heb gezocht, maar kan ze niet vinden met de juiste details?

[Kangsteri]

Thanks. I will make the same comment again: You can make the voltage drop smaller by using 3 diodes, LEDs, or transistors in parallel. 3 of them is usually optimal, cause the advantage is exponentially less. That is good to know if someone wants to make rectenna/lectenna for energy harvesting.