I got to looking at the power requirements and limits to the tl072. In the current data sheet the tl072 which is a jfet amplifier chip it mentions no higher than 18v. In the notes at the bottom of the page, “1. All voltage values, except differential voltages, are with respect to the midpoint between (VCC+) and (VCC−).” Does this mean the points VCC- and VCC+ have to be a potential difference of 18v or does this mean the separate ± supplies individually? I am still getting the hang of understanding how operational amplifiers work. I would just like to know how this works. My multimeter reads the potential difference between the (+12) and the (-12) to be 24v. Just a digital guy getting into op amps. LOL Thanks guys for all your help thus far.
It means no higher than 36v combined (evenly distributed).
Thanks. That makes sense. I was not exactly sure if I was understanding it correctly. I am so close to having a proof of concept done. Hints why I am looking into bread boarding this module. I hope to really customize it.
I guess it’s good that Jameco provides a copy of the data sheet, but the copy they have there is pretty old. For the latest, always check the manufacturer’s site, in this case TL072 data sheet, product information and support | TI.com which gives the absolute max as 36 V (VCC+ - VCC–) and recommends 5-15 V on the supply rails, with a note saying it doesn’t have to be symmetrical, just that total VCC (VCC+ – VCC–) should be between 10 V and 30 V.
It does not look good for the company does it? Although I imagine the engineers who order parts in a real world situation for a product normally keep up to date on many more sources than just the company they order from. Why would a distributor spend an enormous amount of time to keep up to date information for a small society of DIY’rs? I suppose I should take this as a lesson in doing my research better for the parts and concepts I use in my own lab. Thanks for your input. Always nice to have good conversation with intelligent people.
I often have to download manuals and other documentation from an online source, so it becomes second nature to evaluate the provenance and reliability of such material. The manufacturer’s official website is almost invariably the best source and the easiest to use.
I have a cousin who’s career is ensuring chip manufacturers keep their documentation in line with their releases. You’d be amazed how many new products fail to come to market because the spec differs from performance. I stopped downloading and printing data sheets a while ago. Now I just have bookmarks to main sites and even those have changed rapidly over time.
What I’d love to find is a rogue chip manufacturer who’ll make up a dozen “whatever you want” based on an eda schematic or is that a teensy?
@Farabide and this is why I really want some sort of tablet just for PDFs. Like nothing else other than tech sheets, my writing, and perhaps schematics. I been working on. I waste soo much paper just on this. With how often companies change or update I might as well bite the bullet and save up for one.
Buy a cheap second hand nook, the old b&n ebook reader. It costs under 20 usually. These can be rooted and recast as Android machines and the ink screens are perfect for schematics and PDF files. I have a tablet I used during builds and it spent most of the time on the floor or on a chair next to me because it’s bulky, slow (it was very cheap one) and heavy. The nook is small, light and running an android os is scalable. Before lockdown I got 2 old nooks and a backlit nook for £35 on an eBay joblot. One I’ll be using for my music practice drills, another as a Songbook (links,pdfs, lyrics etc) and the 3rd will be for project info and data sheets. Loads of info on Google re rooting and upgrading the nooks, if you’re fine with a high res black and white touch screen you’re golden.
Additional : the nooks have wifi so again just put links to manufacturer data sheets etc.
Kindles can be had pretty cheap too. But I’ve found they can be less than great for viewing PDFs. Then again my electronics work table is adjacent to my computer desk, and if I really need the PDF right at the work table there’s the laptop.
Kindles are ok but not as easy to root and convert. Plus I find the matt nook screen very easy to read. I tried looking at a JPEG schematic using Google cardboard and scaled so I had to turn my head to view the whole thing but putting a cardboard box on your face is not good soldering practice. (A friend told me 
)
I have a tiny work space and desktop realty is precious. I do have a couple of cheap bendy arm phone and tablet holders plus my 11“hp chromebook can sit comfortably on my lap.
Why root and convert? I mean, if you want an e-ink Android tablet for other purposes, sure, but if it’s just for PDFs, Kindles display them.
True. But if you want to use a web browser to link to manufacturer sites and other places like electro-music or here for example its tough. I also like being able to type and interact with my notes which is limited on a kindle. All that said I have an old projector I should just cast my phone to it and have a 2 meter schematic on the wall or a small overlay on a piece of protoboard to trace. The possibilities are endless.
I almost forgot about my project to master arm assembler programming. Its still in the very early stages of planning mind you. I hope to build a raspberry pie system that I can use for on the go experimenting and repair work for when I manage to get with a band. I don’t have any hope of becoming famous mind you, but I would really like to have a band that I can just be myself around. I will be putting up a more up to date public diary on this. Suffice it to say I have my coping strategies that many find very weird. The pacifier avatar I used is not just a piece of random art. Once I get my fantasy pacifier sketched colored and completed it will be a statement of autism. I will be replacing the avatar on all the forums I am on when its done.
To be fair, the specs for ICs that have been around since forever don’t change that much; it’s mostly packaging options being added or removed, and the occasional rebranding 
But in this case, it seems the numbers you looked for were more clearly explained in the new version.
(On the other hand, it’s 2020 and I’d be very surprised if bigger manufacturers don’t provide machine-readable catalogs to distributors – e.g. both mouser and digikey link to the datasheet on the TI site, with a “distId” in the URL, and I doubt they’re maintaining all those links by hand.)
I was just looking at the datasheet for CD4018B. It says “Revised October 2003” and appears to be a scan of a paper version with no OCR 