Recent Posts

1

Beginners / Re: Dimming signal 0-12V from microcontroller (logic level to 12V PWM)

« Last post by Ian.M on Today at 10:34:54 pm »

While you could rework my reply#12 circuit to move the offset resistor R4 to the OPAMP -in, then adjust it to trim out the PWM low offset, the ESP32-C3 GPIO low voltage will vary with how much power the ESP32 is using.  The best option would be to buffer the PWM with a 74LVC1G17, which will give an output that swings to within 0.1V of its supply rails at 100uA load current, then filter and amplify that.  You may need to increase your filter input resistor to keep the load on the gate output low enough to get close enough to rail-to-rail swing.

2

Test Equipment / Re: $20 LCR ESR Transistor checker project

« Last post by dave356 on Today at 10:32:09 pm »

Thanks indman,  will look into these.

Dave

3

General Technical Chat / Re: H5N1 bird flu and how we're risking another global pandemic

« Last post by NiHaoMike on Today at 10:31:42 pm »

https://twitter.com/danibeckman/status/1786650661603446976?t=Ox8-l5JlhQi3QBapsjTsVg
Not a good development. More spreading, more chances for mutations.

All the talk about vaccines misses the point that if there weren't factory farms to multiply the virus so efficiently, there would be less chance of an outbreak happening in the first place and therefore the vaccines to keep it under control would be less important.

4

Repair / Re: TSI361R - Identify obscure/old blown transistors

« Last post by coppercone2 on Today at 10:31:42 pm »

Annealing tin seems pretty hot 230-300°C? and where does it go? Fall inside I guess.
More pics here: NASA Anecdote: Tin Whiskers Inside of AF114 Transistors
They recommend tapping on the top, yeah beat up that transistor's whiskers lol

I was thinking more along the lines of maybe some how treating it to prevent future regrowth, after their vaporized. maybe you can relax the material some how

like with carbon comp you can bake them to regain their performance. that is much simpler system but the concept is the same

5

Beginners / Re: cable shield to PCB?

« Last post by coppercone2 on Today at 10:29:23 pm »

its definately higher performance if you terminate the braid at the connector no arguement

but for the foil, I thought you basically NEED the drain wire to ground it on. I would have zero confidence on a shield going into anything. Well maybe one exception, I have seen a connector that uses a rubber collet to terminate the shield, that might be OK for foil ,but still.. you basically KNOW thats going to tear with any use (but it is the wrong cable to use for a frequently moved application)

6

Test Equipment / Re: Siglent SDS3000X HD and upgraded SDS1000X HD

« Last post by Electro Fan on Today at 10:29:09 pm »

The scopes this thread is about don't have 10Mhz reference inputs, so I feel it's pointless to talk about it here.
There should be a separate thread for that.

Which of the scopes in this thread use a $1199 precision frequency reference?  (Just commenting on what is already in this thread).  And fwiw, maybe the scopes in this thread should have a 10 MHz Ref input.

7

Microcontrollers / Re: Memory model for Microcontrollers

« Last post by tellurium on Today at 10:24:38 pm »

Yeah, AI trains on expert content. For now, it is still easy to recognise it by a behavioral pattern.

E.g. a human pattern is to ask a question, then iterate and follow up.
Example: take a look at the "porting C++ to C" thread - https://www.eevblog.com/forum/microcontrollers/help-porting-2-functions-from-c-to-c/
Or, "starting with stm32" thread - https://www.eevblog.com/forum/microcontrollers/starting-with-stm32-(nucleo-l412kb)/

Note how much OPs iterate over the answers, trying to figure out the solution.

AI's pattern is different - it just asks the question and NEVER does any meaningful follow up. Even when many answers were given, and tons of hints. Look at this thread - not a single meaningful follow up on a on-topic answers (many of them!). Despite all the claims about "genuine interest" and so on.

But I guess AI progresses, and soon we'll see more human-like behavior, including follow-up questions, etc.

8

Test Equipment / Re: Test Equipment Anonymous (TEA) group therapy thread

« Last post by Zoli on Today at 10:18:22 pm »

Calling out to my American friends! I'm in need of some inch size screws, something which is almost unobtanium here in Japan........

If someone can grab some packs of these screws (and appropriate thread taps too) next time you are at the hardware store or making an order from McMaster Carr and stick them in a parcel to send my way, I have Paypal ready and I'd love you long time. 

Flat or oval head (countersunk) slotted machine screws, zinc plated or similar:
6-32, 3/16 long
6-32, 5/16" long
6-32, 3/4" long
10-24 1/4" long
5/16-18, 1/2" long (ideally 3/16" long if available)

For this thing I made. 
https://www.thingiverse.com/thing:6607366
...

I'll bite, if there no other volunteers, but until then: quantities? slot-head is negotiable(to Phillips/etc.)? 5/16-18 I suppose you mean 3/8" is the ideal length, not 3/16"... I'm asking, since I already have some of the stuff(6-32&10-24 tap, some/maybe all of 6-32PH flat head SS screws). PM if interested.

9

Microcontrollers / Re: Memory model for Microcontrollers

« Last post by PlainName on Today at 10:17:55 pm »

So they essentially want gobs of stuff to train their LLM to be the fount of all knowledge? On the one had that would be cool (if it didn't end up behind a significant paywall) - kind of like the next Google search, which was kind of like the next encyclopedia. But on the other hand it may just be masses of complete rubbish so not actually any help in making knowledge more accessible.

Copyright is a double-edged sword. Creators need an incentive to both create and share, but big corps like Disney overdo it with several lifetime's lock-in and payback. IMO, copyright should be limited to the same as patents: 20 years tops. But that's going off on a tangent...

10

Beginners / Re: 5V buck converter debugging

« Last post by DimitriP on Today at 10:10:03 pm »

So does this mean Webench is bugged because it's adjusting Fsw on an IC where you can't do this?

Yikes.
I tried lowering the max current and  Fsw does get reduced. 
I'd stick with a high enough current that keeps WEBENCH Fsw to 2.1MHz so it's running in "sane" mode  
I don't know how many good parts you have left, but it'll be intersting to see what it does if you change L1 to 800nH.
And keep Vin above 5 Volts