Yup same nut! Sorry, I am quite senile. If it was at a show I should be excused na?
BTW why the "ji"? Some Delhi boys tacked it on to the end of my name over on that "famous indian auto forum" no need to "ji" me here too!
Finally magma, thanks to we have the heatsinks for class A amplifcation. Since we live in India (higher ambients) we need to double the area of heatsinks recomended by the websites. A base of 16-20mm would be a minimum to quickly radiate the heat away from the silicon.
Which projects? What happened? Sangram? Did I miss something?
i couldn't agree more, and thats why i see these extrusions as a boon. i built a FirstWatt F2 clone last year in Delhi and it gets quite toasty in summer if it plays through the day...
i am thinking of building a couple of F5's soon, and was tempted by these sinks.
Sangram, how did you fare with 10 inches of the flower extrusion (7 inch width) per side? i was thinking of using two pieces placed side by side to make up the side of the enclosure, so 4 heatsinks in all for a stereo amp. one per device in the F5. i was planning to use a 7 or an 8 inch length.
are the flower type extrusions more effective than the straight finned type? or are they just more compact?
cheers,
mymindinside
Quite well. Sinks are about 44 degrees in winter and about 50 in summer. I don't use thermistors so I have to adjust the bias when the seasons change. MOSFETs are usually about 10 degrees higher when measured on the case tab, which is nicely in line with my estimate of 0.3 C/W between the device and the sink.
Two 5" lengths per side should be perfect for the F5, each device on a single 5" piece.
Well not here
I was replying to a thread on coaxial speaker design, mentioning that I was working on a coaxial project myself along with a Selenium subwoofer. I got a call last night which revealed that my reply was misread to assume that I was copying the Emerald Physics design (which shares absolutely nothing with my creation except the use of a coaxial loudspeaker), and this allegation was aired on another forum - which I used to be a member of and left under acrimonious circumstances.
What worried me the most is that my clarification was not sought here before making these allegations/assumptions - either over PM or on the thread. I was being misquoted while I was a member of that forum, and now I'm being misquoted behind my back. Any project that I work on can similarly be twisted into something it's not, so I guess I'll quiet down and only provide what advice I can, and the rest over PM and email.
Don't back off -- we all lose
I've usually returned to where I was -- I've refused to walk away. I've ignored the stupidity and trash, and I've tried hard to continue as if that stuff didn't affect me. It's just that I've realised that when one of us backs off, we all lose. What we have here (and in other similar long-lasting forums created over time) is too valuable to allow the junk around us to kill it.
I've seen good friends back off from diyaudio, in spite of the moderators doing an excellent job of keeping the trash within limits. Some of the best people simply don't have the time and energy to sustain themselves through all this -- they back off, and we all lose.
Just my two bits. I don't know the details of what happened (is this at the same forum where you greeted me when I joined some months back?) but I don't need to know. Don't back off. Please.
Don't back down. I've been forced to face this choice before. I can either back off and disappear, or I can weather it out, ignore the nastiness, and continue doing what brought me to the place to begin with. (In my case, these weren't audio-related activities.)
I've usually returned to where I was -- I've refused to walk away. I've ignored the stupidity and trash, and I've tried hard to continue as if that stuff didn't affect me. It's just that I've realised that when one of us backs off, we all lose. What we have here (and in other similar long-lasting forums created over time) is too valuable to allow the junk around us to kill it.
I've seen good friends back off from diyaudio, in spite of the moderators doing an excellent job of keeping the trash within limits. Some of the best people simply don't have the time and energy to sustain themselves through all this -- they back off, and we all lose.
Just my two bits. I don't know the details of what happened (is this at the same forum where you greeted me when I joined some months back?) but I don't need to know. Don't back off. Please.
Jeetubhai re-visited
Some old-timers may recollect Jeetubhai. I had written about him in this thread about five hundred years ago.
I re-visited that chapter of my history. His son is in the driver's seat, and is friendly and willing to do business. He has some interesting drivers. Thought some of you may want to know more. Wrote up a page about it on my site.
Some old-timers may recollect Jeetubhai. I had written about him in this thread about five hundred years ago.
I re-visited that chapter of my history. His son is in the driver's seat, and is friendly and willing to do business. He has some interesting drivers. Thought some of you may want to know more. Wrote up a page about it on my site.
Good to see you again Tarun and thanks for the PM.
To clarify, I will not be posting on projects till they are absolutely finished. It also had nothing to do with this forum specifically, it was members of another forum who were copying my material off DIYA and posting snide comments about it over there.
It's good to know the driver business in Mumbai is going to (hopefully) pick up. Usually the reasons for dealers dropping out of that business is because it isn't lucrative enough. Because DIY'ers are generally looking for either the cheapest, or stuff that isn't available here. The range looks decent enough to span full range speakers or sub-sat combos. Good stuff.
@rajesh: Steel cases can be much thinner and can be bent into various shapes over small radii. Thin aluminum is generally not stiff enough or is prone to ringing and rattling. In addition, >5mm walls can be tapped to take screws, for thinner panels one needs to have angled joinery workpieces. Thicker panels also resist warp while working the pieces, and since aluminum is less effective at shielding than steel slightly thicker panels help. Cases with thin panels and a thick aluminum decorative panel are only for effect, though.
To clarify, I will not be posting on projects till they are absolutely finished. It also had nothing to do with this forum specifically, it was members of another forum who were copying my material off DIYA and posting snide comments about it over there.
It's good to know the driver business in Mumbai is going to (hopefully) pick up. Usually the reasons for dealers dropping out of that business is because it isn't lucrative enough. Because DIY'ers are generally looking for either the cheapest, or stuff that isn't available here. The range looks decent enough to span full range speakers or sub-sat combos. Good stuff.
@rajesh: Steel cases can be much thinner and can be bent into various shapes over small radii. Thin aluminum is generally not stiff enough or is prone to ringing and rattling. In addition, >5mm walls can be tapped to take screws, for thinner panels one needs to have angled joinery workpieces. Thicker panels also resist warp while working the pieces, and since aluminum is less effective at shielding than steel slightly thicker panels help. Cases with thin panels and a thick aluminum decorative panel are only for effect, though.
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Why does a amp case need to be 6mm thick?
It prevents external fields from entering your circuit, but the case has to be properly connected at the joints, without gaps.
Gajanan Phadte
Amar Radio has heatsink extrusions of all types, but they are typically not pre-drilled for mounting specific packages. You have to buy the extrusions of the length of your choice, and have it marked accordingly and drill it yourself. There are other shops which offer drilled heatsinks, but they're typically smaller sections and have only TO-3 footprints.
after reading your reply i have just visited to Amar Radio,I have inquired at least 7 type of extrusions from their portfolio but they replied that they dont have.Perhaps,assuming that i am a retail buyer they simply refused.
Oh GOD !!!!!!!!!!! no body is diy friendly.
Funky - I've bought single-piece quantities of heatsinks from him about 8 months ago. Expensive, but he had stock and was willing to sell one-off units.
Has he run out of stock, or does he have stock but is unwilling to sell retail quantities? Talk to the proprietor (the guy sitting to the right) directly, not to the sales clerks.
Also check out Cee Pee Electronics (near Vishal) - he has a smaller selection, but at more reasonable prices.
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