A Super-Simple LED Peak Flasher Audio Overload Clipping Indicator Using the TL431

Where we discuss new analog design ideas for Pro Audio and modern spins on vintage ones.
User avatar
JR.
Posts: 2574
Joined: Sat May 24, 2008 7:21 pm

Re: A Super-Simple LED Peak Flasher Audio Overload Clipping Indicator Using the TL431

Post by JR. » Wed Jan 30, 2019 12:20 am

mediatechnology wrote:
Tue Jan 29, 2019 6:06 pm
Looks like TI introduced an improved TL431"I" as recently as November 2018.
I guess they didn't think it was perfect... :lol:

JR

PS: BTW how long should it take for a sessions to time out? I have to log in multiple times a day...

User avatar
mediatechnology
Posts: 3437
Joined: Sat Aug 11, 2007 2:34 pm
Location: Oak Cliff, Texas
Contact:

Re: A Super-Simple LED Peak Flasher Audio Overload Clipping Indicator Using the TL431

Post by mediatechnology » Wed Jan 30, 2019 5:00 am

The "I" version tightened up some of the reference specifications.
After 40 years of baking the same cake they found a way to make it better.

7200 seconds to submit a form.
So if you're editing a post and it takes longer than 2 hours to submit it will log you out.
https://ka-electronics.com
Learn to code.
"Mr. Sociopath Goes to Washington" https://www.zerohedge.com/news/2019-02- ... washington
"FBI Directing CNN Camera Crew During Raid" https://www.brighteon.com/6000098956001
"Knowing Keeps Us Free" https://www.youtube.com/watch?v=5lC3mpG60sw
"Nick Sandman: The Truth in 15 minutes" https://youtu.be/lSkpPaiUF8s

User avatar
JR.
Posts: 2574
Joined: Sat May 24, 2008 7:21 pm

Re: A Super-Simple LED Peak Flasher Audio Overload Clipping Indicator Using the TL431

Post by JR. » Wed Jan 30, 2019 9:24 am

mediatechnology wrote:
Wed Jan 30, 2019 5:00 am
The "I" version tightened up some of the reference specifications.
After 40 years of baking the same cake they found a way to make it better.

7200 seconds to submit a form.
So if you're editing a post and it takes longer than 2 hours to submit it will log you out.
I have to log back on multiple times a day...(I guess I don't have too). :lol:

Sadly I've had more than one longer post get scrubbed when I log back on... I do not always rewrite the effort.

Like I said It may be a browser thing. I remember being able to back up and find unfinished posts before in the browser cache.

I understand backing us out to save server capacity, but wish it didn't eat my homework. I can get distracted, apparently.

JR

User avatar
JR.
Posts: 2574
Joined: Sat May 24, 2008 7:21 pm

Re: A Super-Simple LED Peak Flasher Audio Overload Clipping Indicator Using the TL431

Post by JR. » Wed Jan 30, 2019 10:02 am

Just wondering why I've never used (or seen) a TL431.

If the adjustable voltage went lower than 2.5V it would rock as a bias string for power amp output stages, but 2.5V is a bit too much voltage. I vaguely recall an article from decades ago about how the 2.5V nominal reference level was necessary to deliver good temperature stability.

I've even used LEDs as low voltage references where I could have used a TL431... go figure. :oops:

JR

User avatar
mediatechnology
Posts: 3437
Joined: Sat Aug 11, 2007 2:34 pm
Location: Oak Cliff, Texas
Contact:

Re: A Super-Simple LED Peak Flasher Audio Overload Clipping Indicator Using the TL431

Post by mediatechnology » Wed Jan 30, 2019 2:23 pm

The TLV431 has a 1.25V reference and I think they are used as bias spreaders.
https://ka-electronics.com
Learn to code.
"Mr. Sociopath Goes to Washington" https://www.zerohedge.com/news/2019-02- ... washington
"FBI Directing CNN Camera Crew During Raid" https://www.brighteon.com/6000098956001
"Knowing Keeps Us Free" https://www.youtube.com/watch?v=5lC3mpG60sw
"Nick Sandman: The Truth in 15 minutes" https://youtu.be/lSkpPaiUF8s

User avatar
JR.
Posts: 2574
Joined: Sat May 24, 2008 7:21 pm

Re: A Super-Simple LED Peak Flasher Audio Overload Clipping Indicator Using the TL431

Post by JR. » Wed Jan 30, 2019 6:09 pm

mediatechnology wrote:
Wed Jan 30, 2019 2:23 pm
The TLV431 has a 1.25V reference and I think they are used as bias spreaders.
The data sheet I looked at this morning said 2.5V (unless I was dreaming), I'll check again (later).

1.25V or higher adjustable would certainly work for biasing up output stages that are often 4xVbe while those popular Vbe multipliers used there are generally thermally coupled to the heat sink to track with output device temperature. A bias device that doesn't change with temperature might defeat that design concept. :oops:

JR


User avatar
JR.
Posts: 2574
Joined: Sat May 24, 2008 7:21 pm

Re: A Super-Simple LED Peak Flasher Audio Overload Clipping Indicator Using the TL431

Post by JR. » Thu Jan 31, 2019 9:40 am

I see what they did there.... TLV is a different part... Perhaps I wasn't the first one looking for lower voltage operation.

So I am not (completely) crazy. :lol:

JR

User avatar
mediatechnology
Posts: 3437
Joined: Sat Aug 11, 2007 2:34 pm
Location: Oak Cliff, Texas
Contact:

Re: A Super-Simple LED Peak Flasher Audio Overload Clipping Indicator Using the TL431

Post by mediatechnology » Thu Jan 31, 2019 10:59 am

And then there's also HV versions and increased-current versions.

To be honest I had been aware of the TL431 since it came out in the 1980s(?) but had never used it.
Like yourself a big ho-hum. Yawn. "Poo-pooed." :roll:

When I needed a shunt regulator for the ZTX851 low noise moving coil front-end I sort of discovered it.
Though it could be quieter in that application it is a common mode noise source so it doesn't really matter.

Going through the datasheet and seeing its' "legitimate" use as a comparator made me think "I may have a home for this circuit some day."

The one thing about using the TL431 is its "Vcesat."

The "LV" version should reduce it's Vcesat.
https://ka-electronics.com
Learn to code.
"Mr. Sociopath Goes to Washington" https://www.zerohedge.com/news/2019-02- ... washington
"FBI Directing CNN Camera Crew During Raid" https://www.brighteon.com/6000098956001
"Knowing Keeps Us Free" https://www.youtube.com/watch?v=5lC3mpG60sw
"Nick Sandman: The Truth in 15 minutes" https://youtu.be/lSkpPaiUF8s

Post Reply