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I forgot why the filter IC in the app note is being used in 4th order mode. You can do 8th order on it, it has two sections *IC has 4, but the schematic by JW uses 2 circuits to make a 'balanced' signal but only one is used. , one is connected but not loaded.. I thought maybe this is done for some kind of high performance reason like current level balance inside of the IC. You can easily turn it into a 8th order filter if you wanted to, but its not written in the note or the datasheet for the IC IIRC.

I think I investigated it. I don't remember if I changed my circuit or not.
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Microcontrollers & FPGAs / Re: Hardware revision + unique serial IC's !!??
« Last post by dgtl on Today at 04:30:11 am »
I've used 1-wire chips for identification. There are some with parallel inputs, that you can use for board revision (DS28E04-100).
I've not seen any with the number on the case; it would probably not be readable with a scanner anyway. Read it out electronically.

Another idea would be using the dynamic RFID tag chips. It acts like an RFID/NFC tag, but has additional I2C interface. Use an NFC reader to scan the tags.
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General Chat / Re: What did you buy today? Post your latest purchase!
« Last post by PA0PBZ on Today at 04:27:48 am »
A CubeX duo 3D printer

That looks like a nice one, why did Steve let it go, he got something better?
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There are two basic schemes for BLDC control:
1: varying the supply voltage to the power stage, either DC or PWM
2: gating a PWM signal into the drive circuit for the power stage.
In both cases, the "Master" signal for the power stage drive is the feedback from the Hall sensors.

The opportunities for adding advanced features on top of this are of course infinite.

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Repair / Re: BJT replacement - pulling my hair out
« Last post by jaunty on Today at 04:26:55 am »
They should work fine in that circuit.  The hfe might be a bit different depending on the version of the 2SD234 and 2SA490 that are in there but that shouldn't be an issue in this case.

I find it a bit strange, though, for the transistors in positions tr2 and tr5 to die, I would have expected tr1 and tr6 to take the brunt of any abuse.

What is the issue with the supply?



As they are pretty old BJTs they seem to be the most basic form of those transistors - i can't find any other versions of them. Actually - they didn't 'die' as far as i can tell - but the power supply started blowing fuses - so I started rebuilding the entire thing, not having found any obvious culprits. In the process of trying to resolder everything back together i managed to break off one of the legs of one of the 2SA490s (there are actually two of each) - so I figured maybe rather than risk circuit instability it might be better to simply replace them all anyhow (esp. considering the thermal compound has now fossilized etc) ... so here i am. I hope that explains it well enough.

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Repair / Re: Sony Bravia KDL-40RD455 repair
« Last post by wraper on Today at 04:25:27 am »
How about TLV73311PDBVT? Would it work alright? I ask this because this one is more accessible for me than those other two.
Should be fine.
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Test Equipment / Re: Test Equipment Anonymous (TEA) group therapy thread
« Last post by PA0PBZ on Today at 04:25:00 am »
The thing with my Samsung (and I guess Cerebus' tablet) is that you could expect the charge circuit to be ok, and I didn't 'dick around' with it, never left it in my car and there was no visible damage or suspect construction problems as with the Note. I did punch a very small hole in it and let the gas escape and it worked ok for another month. After that the capacity dropped like Flynn's trousers and I replaced it. I still have it so if anyone has a suggestion what to look for I can do it (outside  ;) ).
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General Chat / Decapping integrated circuits
« Last post by Jane on Today at 04:21:58 am »
I would like to replace an  integrated circuit on a mainboard. A problem is that a manufacturer removed any text on the circuit. If I decap the circuit (in a nitric acid) I can see the inner circuits. Is it common a manufacturer put a model number on the wafer( inside of the circuit) or not?
Anyone knows?
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Vintage Computing / Re: What was you first computer?
« Last post by taydin on Today at 04:20:47 am »
My first computer was an Amiga :)



About two years later, I bought my first 80286 PC. And then I saved money for 1 year to get the 80287 math coprocessor for it.
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But my sources of such information, are usually from somewhat unreliable, internet scare-mongering, and rumour producing sites. So what the actual reality is really like, I don't know.
Since military stuff, tends to be kept tight lipped, it is difficult to get reliable sources of information about it.

Indeed, it's one of those areas where "Those that know don't say, those that say, don't know". Back in the day I knew enough people in the right places to probably have had, should I have wanted to, a fair picture of the real situation. Nowadays I'm as blissfully ignorant as the rest of the public. What I can say, based on previous insider knowledge and comparing it to what's said publicly is that the Politicians and people senior enough in the Forces/Police/Whatever to be regarded as members of the political class are almost always clueless about the real situation, and the journalists and pundits that talk to them, also equally devoid of clue.

Even were I still in a position to know what's what, I'm sufficient of a patriot that I doubt that I'd do more than make comforting noises in public if all was well or, if all was not well, keep quiet and go and hassle my (useless, careerist, spineless, party-line-towing) local MP.
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