Shockley diodes - Page 1
Forum section: electronics / general

author: Addicted2AnalogTek
author_rank: Frequent Contributor
timestamp: February 26, 2018, 05:39:14 am
content: For the past hour I have been going through and labeling random components that came with lots I had purchased when I came across an envelope labeled "SHOCKLEY DIODES". Many of them are of the type that came off of a production line, but there's also a few obscure ones. The few diodes with date codes on them are from 1965.I find it rather unlikely, but I can't help but think the black one in the photo might be a prototype. It's got what looks to be hand painted black epoxy coating on it. It has long, thick leads with indentations on the ends where it probably was clamped into a test fixture or curve tracer. The print on the clear tape is golden. I don't know anything about the history of early discrete semiconductors and their prototyping methods, but I'd bet on it that the EEV community has a wealth of knowledge on this subject!Does anyone have any idea what it is that I'm looking at? I wish I had a high quality camera or microscope. All that I'm working with is an iPhone camera..(I forget how to post pictures here as thumbnails..)

author: meeder
author_rank: Regular Contributor
timestamp: February 26, 2018, 05:47:11 am
content: I think that they are mislabeledhttps://en.m.wikipedia.org/wiki/Schottky_diode?wprov=sfla1

author: BrianHG
author_rank: Super Contributor
timestamp: February 26, 2018, 05:48:02 am
content: Quote from: meeder on February 26, 2018, 05:47:11 amNo they are not. Schottky diodes did not exist in 1965. They actually are Shockley diodes. A different technology.https://en.wikipedia.org/wiki/Shockley_diode

author: Addicted2AnalogTek
author_rank: Frequent Contributor
timestamp: February 26, 2018, 05:57:23 am
content: Yes, they are definitely Shockley diodes, not schottky diodes. The other ones in the pouch are 4E20, 4E30, 4E40, 4E50, M4L3053, M4L2054, and the ones with the date code are ST36. Date code 6527.

author: BrianHG
author_rank: Super Contributor
timestamp: February 26, 2018, 06:03:02 am
content: I wonder if you can design a project which makes specific use of the reverse turn off current characteristic of the Shockley diode to operate.

author: BrianHG
author_rank: Super Contributor
timestamp: February 26, 2018, 06:53:22 am
content: Example:

author: tautech
author_rank: Super Contributor
timestamp: February 26, 2018, 07:45:36 am
content: Quote from: BrianHG on February 26, 2018, 06:03:02 amThey're probably the predecessor to unijunction transistors.Quote from: Addicted2AnalogTek on February 26, 2018, 05:57:23 amSeem like prefect candidates to send to Dave as the basis for an interesting video.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 26, 2018, 11:19:59 am
content: Basically a DIAC, but not optimized for symmetrical, bidirectional operation.Tim

author: Addicted2AnalogTek
author_rank: Frequent Contributor
timestamp: February 26, 2018, 06:03:47 pm
content: I intend to play around with them a little tonight when I get back home. It's quite challenging finding any datasheets for these since they're so old. I know I can at least find data for the 4E20 and maybe more off the Tek semiconductor list, other than that I'd probably be digging up PDF copies of semiconductor books from the 60s and 70s.I'd definitely be down to send a few to Dave, though!

author: schmitt trigger
author_rank: Super Contributor
timestamp: February 26, 2018, 06:12:36 pm
content: Anyways, you got some piece of history in your hands!Many companies and institutions claim to be the "founders of Silicon Valley".However.....Shockley semiconductor definitively helped launch the "silicon" part of Silicon Valley.

author: Addicted2AnalogTek
author_rank: Frequent Contributor
timestamp: February 26, 2018, 08:50:45 pm
content: My question is: If this is a prototype and it really is a true piece of history, what do I do with it?? History deserves more than a place in someones parts stash boxes.

author: Addicted2AnalogTek
author_rank: Frequent Contributor
timestamp: February 26, 2018, 09:17:07 pm
content: There are several pages regarding William Shockley and Shockley diodes in the database of the semiconductor museumhttp://semiconductormuseum.com/Museum_Index.htmhttp://semiconductormuseum.com/PhotoGallery/PhotoGallery_Shockley4E30.htmThere's a schematic on page 4 for a sawtooth oscillator that I'd like to play around with a bit. There's also a schematic on page 5 for an audio power amplifier that I might have the correct diodes to build if the schematic had all of the necessary info. The diode I've posted a picture of above will most certainly not be 'played with', though.

author: schmitt trigger
author_rank: Super Contributor
timestamp: February 27, 2018, 05:16:45 pm
content: Quote from: Addicted2AnalogTek on February 26, 2018, 08:50:45 pmI would frame one of them, with a background of printed datasheets and/or application circuits. Perhaps a photo of Dr. Shockley himself. You know, a nice collage to hang in your office or workshop.I would also consider donating one sample to the semiconductor museum, in case they don't have any samples.

author: RandallMcRee
author_rank: Frequent Contributor
timestamp: February 27, 2018, 07:18:04 pm
content: Better would be a circuit that incorporates the diodes as a work of art, ala Jim Williams and others.

author: rsjsouza
author_rank: Super Contributor
timestamp: February 27, 2018, 07:30:16 pm
content: For starters, I would at least take a nice photo of one or a few and add to the Wikipedia article.

author: Addicted2AnalogTek
author_rank: Frequent Contributor
timestamp: February 28, 2018, 02:45:01 am
content: I'm going to see if I can borrow a friend's professional photography skills and start with some HQ pictures. At that point I'll submit them to wiki and the semiconductor museum, then see what comes of it.

author: meeder
author_rank: Regular Contributor
timestamp: February 28, 2018, 06:09:41 am
content: Nice thread here. A whole new world is opening up for me here