- Joined
- Jun 21, 2012
- Messages
- 4,878
Too bad, since you purchased from China, that you have no idea what those 30 "devices" really are. Finding out "fer sure" would cost more... much more... than what you would have spent purchasing from a North American distributor the original lot of 10. But, hey, ya pays yer money and ya makes your choices. I have bought electronics stuff from China, mostly through Amazon. Once I tried to purchase via email exchange for a project that used stepper motors. I have had no problems with Amazon, but there was a huge language problem trying to communicate, both verbally and through documents, with the Chinese. I finally gave up trying to source a motor from China when the person I was trying to buy these motor for decided to purchase them himself.So now I have 30 of them.
Still waiting for those motors so I can continue with that, now almost ten-year old, project. Both he and I are getting older, so it may never get finished, but if it does, I will send a link to where you can purchase one... of the stepper motors that is. Cannot say how the motors will be used, because of an NDA I signed for the person who wants the motors.
I need to take some time now to go back and read the whole thread of dialog between you and AudioGuru. If I recall correctly, he was the person who first discovered, and then reported to this forum all those problems in the Asian power supply... not only discovered but also explained and corrected! If it wasn't this thread (which is old) it might be a very much older thread. Whatever... what I need to know now is the final corrected schematic with parts identified by symbol and value. I guess a BOM (Bill of Materials) would be a little much to ask?
You might as well test them for functionality, too. Some, all, or none of them may be parts actually manufactured by Texas Instruments.when I get a chance I'll refresh my memory about this and test some of them to see if they have the appropriate resistance between the offset pins.
A small ZIF or Zero Insertion Force socket would speed up the testing process. Functionality testing can get complicated really fast. Testing just the two "offset" pins for resistance and rejecting those devices that show "no continuity" is just a minimum test to sort bad from possibly good. Even a "bad" chip could turn out to be "good" if only you knew more about it. And all the "possibly good" devices that "pass" the continuity test could be fakes or defective. However, I think you can now purchase a "smart socket" instrument that analyzes whatever device you insert into it and then tells you the nearest equivalent part number. IIRC, it was a bit pricey... maybe needed a cloud-based database to store specs for every integrated circuit or device it recognized.
Maybe I should use this website's "search function" instead of cluttering us space on your screen!