On a related note, I heard this 2nd hand from a guy who was talking to CAT about a module they wanted to have 80V over voltage protection for a crazy amount of time (minutes). My friend asked what scenario required that and it was something like this: Guy at a construction site can't start his bulldozer. He doesn't have jumper cables, but he's got an arc welder... I don't know if that actually happened but it would not surprise me.
That said, I may not understand what a 'load dump' condition is, myself -- I always thought it referred to the common case where a high current load is switched off abruptly, causing the voltage to spike until the alternator's regulator circuit can respond by reducing the field coil current.
Disconnecting the battery would not be expected to cause such a condition, since the charging current is not all that high most of the time compared to other loads. I wouldn't expect much of anything to happen when disconnecting the battery from a running car. It should just keep running.
Alternators tend to produce a constant current in proportion to the field winding current (the variable the voltage regulator controls). When you disconnect the battery the alternator attempts to maintain that current by increasing the voltage. The voltage regulator has to reduce the current in the field to close to zero to stop this voltage surge. The field has some magnetic energy (inductance) that the voltage regulator has no good way to get rid of quickly. So the output voltage zooms up to maybe 10 times the normal voltage for an extended period and any electronics in the car might be very sad.
Adding just a transistor to handle the high impedance of the guitar and a few cents worth of resistors and capacitors, one could build a tiny amplifier that once plugged to a 12" guitar speaker could make some serious rock'n'roll!
I remember taking most design ideas from this gold mine: https://www.sonelec-musique.com/electronique_realisations.ht... (unfortunately only in French)
> While the -6 volt supply spec caused little trouble for the LM383, it meant that all the other electronics in a car needed to voltage regulator that could provide protection.
The other components need protection anyway. What is the connection to the LM383?
> Some one made the joke that the lateral PNP's were so bad that even delco would not be able to destroy them.
Why are bad lateral PNP's hard to destroy? Is he talking about PNP's inside the LM383 or inside other power supply circuitry that's supposed to provide protection?
>A skunk works layout of a lateral PNP regulator ultimately made its way to delco. And sure enough, they could not destroy it. They loved it. And National Semiconductor got into the business of making PNP output regulators.
I have vague intuition that p-type silicon has lower mobility and worse ohmic-junction performance than n-type silicon. A real semiconductor engineer should verify, but I believe the core of the dig is that the low performance acts like intrinsic protection: the PNPs simply couldn't conduct enough current to destroy themselves, at least not in the multitude of spectacular fashions as the NPNs.
However I don't think this was the main part of the joke, rather it's that lateral transistors are _way_ worse in pretty much every conceivable metric than vertical transistors save two - they are hard to destroy and cheap. So add 'lateral' to 'PNP' and you basically have 'worst possible transistor', so bad that you can't kill it.
The hard part is actually the parasitics that come into play (capacitive/inductive coupling between signal lines and the bulk), and dealing with that when synthesizing the design.
Cheap clock radios use them. They also use an 8-pin AM/FM digital radio IC: pins for 32 KHz crystal, I2C, antenna (loopstick for AM), and audio out. No coils, inductors or filters needed.
Paging Steve Gibson: somebody reinvented your dog silencer[1][2]!
[1] https://www.grc.com/tqc/TheQuietCanine.htm
[2] https://groups.google.com/forum/#!topic/portable-sound-blast...
Funny thing is that I remember that back in the day I hated those Courier-font-style publications. They always seemed hard to read compared to well type-set documents. And I never understood screenplay writers obsession with Courier 12[1]. I guess the web is so noisy and cluttered today, that even harsh black Courier on a white page is a relief.
[1] Screenplays are usually written in Courier 12. I only know that because I sometimes read screenplays, for movies that interest me. It's fun and doesn't take as much time as it does to watch the movie.
I don't know why I find this as hilarious as I do, but thanks for sharing.
Personally, I haven't read many screenplays, though I did read the original one for Monty Python and the Holy Grail and it bears very little resemblance to the final film. There's a whole section about buying pet ants from Harrods.
Oooh, found my project for the weekend!
"Now it is no longer possible to do this since the packaging department had redesigned the package"
aww shucks
Wear safety glasses!
this week I’ve been looking into making a wireless speaker similar to a Sonos play:1. In terms of the streaming mechanism is was going to use a raspberry pi running as a snapclient, wired to a class-d amp board and a, say, 3” driver. I thought I would find a load of projects using a pi + amp + driver in a small box combination, but I must be looking in the wrong place.
Does anyone have any top tips of examples of setting something like this up? What amp / driver combination to use? I’m not looking for anything amazing, and I’m sure round 1 will be a learning experience, but any help appreciated.
https://sites.google.com/site/undefinition/isetta
He mostly just lays out the speaker and crossover design; but as he mentions a search for "TPA3116 2.1 amp" will give you lots of results on Amazon, AliExpress, and Parts Express.
PE's forums are good, lots of people have tackled similar projects:
http://techtalk.parts-express.com/forum
For anybody else interested in this hobby, there are lots of fantastic kits out there, primarily for bookshelf/tower speakers and subwoofers.
https://www.parts-express.com/cat/speaker-kits/286
The product page for the C-Notes (a fantastic value at $100/pair!) kit has a build video which gives you a great idea of the process and the tools you'll need. Process is similar for any flat-pack kit.
https://www.parts-express.com/c-note-mt-bookshelf-speaker-ki...
Of course you can also go as far down the DIY hole as you like, designing your own electronics and selecting drivers, etc.
Here's how I did it:
Last year, I visited Taiwan and China, I basically went to scout for speaker suppliers. I shortlisted a couple, but I realized, the popular they are, the pricier they are - regardless of the quality. Then, I realized something shocking. Actually, most speaker manufacturing is done in Nanjing (and one more location starting in N, forgot). These factories just stick the brand names on top and license it to these "big brands". And you pay a premium for that. So, I visited one direct supplier in Nanjing. It was a very small shop. I just walked in, placed an order for a pair. The whole set of 4 speakers (2 woofers and 2 mid-ranges) costed me in total of $200 US roughly. I purchased two 6.5" aluminium cone woofers and 2 golden capped full ranges. I like woofers with large Xmax, so I bought these for bass units.
You can purchase from AliExpress too, although it's slightly pricier. But most speakers from China, contrary to popular belief, are very very high quality. In fact, the consumer audio space such as Sony, Samsung, etc. use much lower grades than what's normally found on AliExpress.
As for amplifier, buy a half-decent board. Strip out all the cheap components, spend 3x the price of the board on really good quality components. For the TPA3116D2 board, this place is a good start [4]
Hope this helps. Cheers.
[0] https://www.instagram.com/p/BplhIIqHNhl/
[1] https://www.instagram.com/p/Bpl71mUHLbm/
[2] https://www.instagram.com/p/Bm02F4OgAwX/
[3] https://www.instagram.com/p/Bppl-dsHWuW/
[4] http://www.diyaudio.com/forums/diyaudio-com-wiki/252663-tpa3...
In regards to your project - it depends how many sub-projects you want to spawn. I've got https://www.ebay.com.au/sch/i.html?_from=R40&_trksid=m570.l1... hooked up to my PC and some old speakers - 3.5mm jack, USB DAC and Bluetooth support. It's variable voltage up to 12V (I think). Funnily, if you supply it with 5~7 volts, you'll get a "low battery" audio cue - despite there being no battery connector anywhere.
The newer version of this has the volume knob in a silly place.
That was until I nearly burned the shed down charging one up. I was confined to alkalines then. Boo hiss.
This first paragraph is almost gibberish to me. In a good way. I just find it humorous that there are so many in-the-know words here.
TDA200 and LM383 are obviously product or device names. Bruno Murari is obviously a person's name (a design engineer, as the sentence points out!), SGS is obviously a place where one works, likely a company.
You should have no issues with the term "reverse engineering" if you are on Hacker News. So that only leaves "automotive power amplifier using only five pins". You probably know what "automotive" and "five pins" means, though, so even less than that.
And then it's absolutely obvious that you won't know what a "power amplifier" is if you don't have some connection to electrical engineering, but it's useless to point that out. Imagine if every electrical engineer did that on articles on biology, chemistry or economic sciences.
These are names of things. The sentence structure makes that clear, and makes it clear how they relate. They are not "in-the-know" terms that are lacking definitions. It is not gibberish, just like the sentence "Jane gave Sue a letter from Bob" is not gibberish, even though nobody defined "Jane", "Sue", or "Bob".
From the article, I knew the LM383 was a 5 lead audio amp. From context in the sentence it was clear that the TDA2002 is a predecessor of the LM383. I don't know who Bruno Murari or SGS are, but again, context makes it clear that Murari worked at SGS when he designed the TDA2002.
What part did you find to be gibberish?
