Cx5 is a strange material that’s a favorite of model makers and prop replicators. It’s kind of like a wax, kind of like a clay, and a little bit like a plastic. Now it’s a 3D printer filament. It looks very interesting for sculpted and highly detailed models, something the 3D printing scene hasn’t had yet.
So you want a CNC machine, right? Tormach makes a good one, and here’s what it takes to put a PCNC440 in your garage. This is an incredible amount of work and a great excuse to buy an engine hoist.
[Zemnmez] could find dozens of apps and webpages that would calculate resistor color codes for him automatically. What he couldn’t find is one that would do it in reverse – i.e. type in a resistor value and return the correct color code. He made this.
[aggaz] needed a way to connect multiple MIDI devices to his computer. The MIDI spec provides a neat piece of hardware for just this occasion – the MIDI thru box. The only thing you need to build a single MIDI thru box is an opto-isolator and a buffer. It’s easy enough to build, although the DIN5 jacks used for MIDI devices are pretty expensive nowadays. (FWIW- We get an invalid certificate error when loading this page but you should still be able to load it.)
AliExpress always has some interesting stuff on it, and [Ethan] found something very cool. They’re A8 CPUs found in the latest iPhone. Are they real? Who knows. I bought one, and you’re going to get pictures in another links post in a month or so.
The Game Boy Micro was released by Nintendo in 2005 and quickly became one of the coolest and most desired handheld consoles on the planet. You need only look at the eBay listings for the Micro as evidence of its desirability. [ModPurist] took an old DS Lite and converted it into a Game Boy Micro – same idea, larger package.
The resistance app is cool…ElectroDroid also goes both ways. Teehee goes both ways…
http://www.sphere.bc.ca/test/build.html
A printable circular sliderule. Mark both the inner and outer rings for 20 and 10% resistor values. (1.0, 1.2, 2.2,..5.6…)
Then when you need to build a resistor divider, line up the ratio (e.g. 4/3) on the rings and look where opposing markings are closest.
Does anyone has a bit of knowledge about fake chips ? what’s worth copying, how are they copied, what is probably not fake, degree of fakeness etc? I hear mostly hearsay, drunken rambling and documented anecdotes once in a while on fake chips (like the famous FTDI stuff), but I can’t find anything a bit intellectual on that topic.
There care lots of fake chips out there. The more basic the chip the easier they are to fake, for instance there are lots and lots of fake voltage regulators (https://www.youtube.com/watch?v=JLwJb4MVbls). Then you have the likes of these fake atmel chips from china (https://www.youtube.com/watch?v=Sl4D71NRY8A). Chips aren’t really hard to reverse engineer because if you look at the datasheets for the chips most of the time the internal circuitry is drawn out for you and even if it wasn’t if your really good you could work ou what is going on inside anyway.
I don’t know what you mean by degree of fakeness but when it comes to computer CPU’s sometimes people have scrubbed the writing off an old CPU and printed more text on them so they look like the latest intel i7’s. These processor’s are as fake and crappy as it gets as they wouldn’t even work in your computer. Then next you would have a badly copied chip when it will either provide basic functionality or is made from cheap materials and won’t last very long especially if you push towards upper limits. Lastly you have a clone, basicly a like for like clone where you won’t be able to tell any difference in performance or look.
So summing up if you buy your chips from China you have a good chance of coming across fakes, Even if you buy from trusted suppliers there is still a risk of getting fakes. There is no way really to prevent fakery butif you want to avoid by direct if you can or from recommended suppliers.
I hope this helps.
if it’s like shoes, you have different degree of fake stuff: production at night by the same factory, resell of the rejects,, desoldered stuff, manufacturing blueprints travelling a bit more than what the client bargained for, design form the ground up of a different chip but with deceptive markings etc. You can feel that the “night shift” doesn’t produce the same quality as the scrap bin, etc.
I’m all for buying original brands from cartel distributors, but any single 0.2€ capacitor will cost me 20€ in shipping and handling, so it’s not going to happen until I buy them with other’s people money and sell to rich Californians (which doesn’t really feels like a liberal dream). But I’d rather buy original Chinese components, with their Chinese brand on it, but they are hard to discover, all those western brands with 20€ shipping are flooding the internet with advertisement for expensive products, and they are basically killing the meritocracy.
Lot’s of different fakes –
Small micro controller used to emulate hardware
Fake clones of die
Chip numbers ground off and higher spec numbers printed on
An extremely popular fake is phone chargers, especially when a company like Samsung charges extortionist prices. For example, a 2.1 amp output charger for the S4 and Tab 3 (and several other Samsungs) sells for over $30 direct from Samsung.
I bought one for a few $ off eBay. It wouldn’t charge my Tab 3 at all and would barely charge my S4. Then it died. I had a very close look at it with a magnifying glass and found the printing on it was different, logos different size and location and the color was wrong. It was also nearly a gram lighter than the real one. I got my money back.
Then I paid a bit more for another one, selecting one that had large images that I carefully compared to my genuine S4 charger. Size, position, color etc of the printing all looked good. Nope, another fake that was only good for about one amp and would not charge the Tab 3 at all. Very close examination showed the printing color was very slightly off and the Samsung logo was just a smidge different size. The rest of the printing and logos were spot on. Another refund.
It just chaps my arse to pay Samsung’s gouging price for a charger they have made in China at a couple bucks a pop. If they didn’t expect to make an extreme profit on them, the fakes would not exist! Put a reasonable $10 price on the genuine one and watch the counterfeit market dry up.
I bought a Belkin in emergency at an airport. 2.1 amps, a little bit less than 25$. Works like a charm. You could find the same for cheaper in a normal store. But the point is : I never buy any USB charger off ebay or aliexpress, too much scam.
You made a point : samsung and apple are selling their chargers way too expensive. But in the meantime, I don’t understand why people are going blindly to these brands only. There is a lot of cheaper brands with more experience in designing chargers, hearphones and other accessories.
isn’t it the same with chips? why does everybody go to FTDI instead of going to smaller Chinese brands? (well truth is: because if the datasheet is in Chinese).
While the eBay fakes are horrid to experience. You don’t need samsungs own charger. I use an Asus 2.1A supply for my hp steam tablet. Anything with a 2 or so supply and usb out is fine. Belkin as mentioned have functional items. Powered usb hubs can do the trick. I actually use a portable powerbank with dual 2.4a output
I don’t think this is a fair comparison. It may be true that the US products are overpriced but perhaps not as far as you think.
With the US product you get –
1)A product that is certified by someone that has in interest in not having to pay much more insurance should the thing electrocute someone.
2)Someone to sue if it burns the house down.
3)Support services
at the same time US companies have to pay –
4) import taxes
5) product certification / safety inspections
6) inefficient US transport costs
7) support services
So yes there more pricey but I would still pay the extra just for point one above.
I might have been lucky, but so far I had pretty good deals with AliExpress. Ordered 10-20 times so far and never got a fake transaction or a defective component. Last order was for a lot of analog multiplier in order to compare the performances of this project:
https://hackaday.io/project/7542
The multipliers ordered from AliExpress were supposed to be some Analog Devices chips, AD835. At Digikey, AD835 can be bought at about $20/piece. From AliExpress, they were like $1.5/piece.
I was expected a totally fake and not functionally chip, but to my surprise, when the package arrived I tested them and they really are analog multiplier. I didn’t test them against the full specs, and I am not sure if they were produced by Analog Devices, but at least they are working analog multipliers good enough for experiments.
Bottom line, so far I am very happy shopping hobby chips/parts/modules from AliExpress.
MIDI nominally uses current to signal, not voltage. The CD40106 is only specified to be able to sink 1mA when powered at 5V, but MIDI’s current loop specifies 5mA.
Unfortunately, I cannot currently load his images to see what voltage he’s running this buffer at.
5V. So using CD40106 wasn’t a good idea after all?
I mean, if it works, it works, but it’s out of spec, so it may well at some point in the future magically not work for no discernible reason because it can’t sink enough current.
Until now it worked, but it’s possible that I did not push it, (I tried it with only a pair of volcas at the same time because I still need more cables!). But I want to thank you for your comment/suggestion. It’s definitively something I will take in account.
Too hard to find a color code calculator ? Just type “resistor color code generator” in google.
Seconde result : http://www.electronics2000.co.uk/calc/resistor-code-calculator.php
The wording on the MIDI section confused me a bit, until I realized he wasn’t trying to route multiple instruments IN to his computer… he was trying to use (one) computer MIDI output to drive multiple synths.
The color code page has the colors wrong. This is becoming more common. The *REAL* color code is designed so that color blind people can read them to.
Unfortunately, color perception is different for *EVERYONE* so if you choose colors that look right *to you* then they *will* be wrong for others.