If you spec 1oz copper for O/S layers, it usually gets plated up to 2oz.
I did a quick Google search, "pcb heat sink calculator" low and behold TI has an online calculator.
PCB Thermal Calculator - TI.com
Also an app note
http://www.ti.com/lit/an/slua566/slua566.pdf
There you go Jan, hope it helps you out.
I did a quick Google search, "pcb heat sink calculator" low and behold TI has an online calculator.
PCB Thermal Calculator - TI.com
Also an app note
http://www.ti.com/lit/an/slua566/slua566.pdf
There you go Jan, hope it helps you out.
I am looking at 0.5 inch^2, both sides of a 2-layer board stitched together (36 small vias). Total power to be dissipated, not sure, this is music ;-) guesstimate less than a watt from a TO220.
Would that jive?
Jan
Attachments
Stuck on that TO-220 🙂
Again, looking at figure 3, 0.5 sq inch is not much, best you are going to get is around 50 degrees C per W, so for die temp add ambient, say 25C, you get 75C die, which is safe. max junction is 150C, thermal shutdown is 175C.
The TO-220 package free air is 65C/W
You are using TH comps, you can make the copper pour area (radiator) bigger, if you want, just put some solder mask around the areas that extend past your thermal pad since it is at the V- potential unless you use an insulator for the flange to pcb interface, which is probably not a good idea.
Again, looking at figure 3, 0.5 sq inch is not much, best you are going to get is around 50 degrees C per W, so for die temp add ambient, say 25C, you get 75C die, which is safe. max junction is 150C, thermal shutdown is 175C.
The TO-220 package free air is 65C/W
You are using TH comps, you can make the copper pour area (radiator) bigger, if you want, just put some solder mask around the areas that extend past your thermal pad since it is at the V- potential unless you use an insulator for the flange to pcb interface, which is probably not a good idea.
Normally one computes for worst case dissipation.
http://updatemydynaco.com/documents/Class_B_Amplifier_Dissipation_Calculations.pdf
http://updatemydynaco.com/documents/Class_B_Amplifier_Dissipation_Calculations.pdf
Well another completely off topic question for my friends here.
As I am updating my web presence, if you were tasked with finding a company to provide a sound system for a church, auditorium, athletic field or other professional purpose, how would you search for it?
As I am updating my web presence, if you were tasked with finding a company to provide a sound system for a church, auditorium, athletic field or other professional purpose, how would you search for it?
Ed, you'd want to talk to some SEO guy. (Search Engine Optimisation).
It is a misconception that if you get the terms right, you end up up top. This is no longer the case since probably almost a decade.
Jan
Actually the search engine folks will give drop you in the ratings if they detect attempts to influence the results.
The current techniques are to have your website listed on other sites, have good reviews and good key word content.
(I have relatives making careers out of that internet stuff.)
But the test is how many folks even here can find my website without using my name. Even better is locating all of my pages.
Yet another topic that I would like to reintroduce, hi end audio, is still alive in many areas, as I was reminded by an engineering friend who recently got a job in a Chicago hi fi store. Yes, hi end phono turntables are still available, and careful set-up, apparently necessary for best performance, is offered.
I suspect that many here who criticize vinyl have never been around really good vinyl playback, so you criticize from your compromised position, but apparently it has made quite a come-back.
I suspect that many here who criticize vinyl have never been around really good vinyl playback, so you criticize from your compromised position, but apparently it has made quite a come-back.
It never went away in my house. Unless my poor british turntable and swiss cartridge are not high end enough. I checked the like for like replacement cost and with the inflation of the new boutique world of vinyl the front end comes out at about £8000. I am so glad I bought it 25 years ago when prices were on a downward trend.
I am all for reasonable cost phono playback, as I have only a relatively modest turntable (Linn LP12) and a Lyra MC cartridge. I can't justify any more myself, BUT I do know that there is better out there, yet my set-up seems to beat comparable digital playback, even at the SACD level. Ultimate vinyl playback appears to still be very expensive, but it is still real to the serious listeners who can afford it.
I think our front ends are comparable, and like you I cannot justify more. If I could an ELP laser turntable would be on my list. I believe Jan had a play with one and was impressed.
No offence John C. and other vinyl fans or fanatics, but those are just your opinions just like mine are.
To me it is just crazy, the costs you are speaking of, hearing and knowing that you have this inherent background vinyl surface noise, that is so real and just gets worse with every play. Also the static discharge pops, vinyl imperfections, tracking errors, that are a reality, unless you go through a thorough static discharge cycle, have a humidity controlled environment. What a PITA.
In some cases for me, my LP's sound better when I run them through my de-clicker software, Steinberg Clean! 1.5.
How do you dismiss these media/reproduction artifacts as being good for overall sound quality?
I hope that you can at least agree that no LP playback system is going to do away with these artifacts unless it is contact-less and has no tracking error.
Surely every method has it deficiencies but the above imo outway the issues that you would have with SACD or equiv. reproduction system, at a fraction of the cost. Maximum bang for your buck makes a lot more sense to me.
Also knowing that anything new in LP production, is derived from a digital source to begin with. I believe there are no more recordings being done on analog tape anymore, let alone mixing, mastering. Just makes no sense to me at all.
I am sure we have all been through this over and over, just I do not get it, maybe I am just stupid 🙂 been called worse 🙂
I recall my Dad saying he did not listen to the pops and scratches, he just listens to the music, I just shrugged my shoulders and said okay I sort of get it, old school thinking.
Okay I said my piece, delete or disregard as you wish. Back to more important things, Mom needs to be feed her home made Spaghetti 🙂 Cheers Rick
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On top of all the issues with vinyl, there is talk of digitizing the pristine analog signal from the phono cartridge to compensate its frequency response, etc.. In that case, seems like one may as well go digital all the way. It's going to sound digital either way.
Mark, I can't work out if you have finally developed a sense of humour here or being serious?
quite debatable, dubious in fact if allowed good ADC/DAC, required Blind listening protocol
people will bet stacks of Benjamens against and thousands of trials never required Clark to pay out for Blind listening test comparisons between amplifiers which are expected to be much more variable that current, competent 24/96 digital audio
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