Hi ,
I'm just wondering what are the differences in performance between the two. I'm looking for 10000uf 80v 85c caps for an amplifier project and saw that the screw type caps are much bigger physically with the same spec. Most solder type 10000uf 80v 85c caps measure 35mmx50mm in size but the screw types measures 50mmx80mm or bigger in size with the same 10000uf 80v 85c specs.
Do I get any advantage in terms of electrical performance if I use the more expensive and physically bigger screw type caps? I hope someone can enlighten me .
Thank you.
I'm just wondering what are the differences in performance between the two. I'm looking for 10000uf 80v 85c caps for an amplifier project and saw that the screw type caps are much bigger physically with the same spec. Most solder type 10000uf 80v 85c caps measure 35mmx50mm in size but the screw types measures 50mmx80mm or bigger in size with the same 10000uf 80v 85c specs.
Do I get any advantage in terms of electrical performance if I use the more expensive and physically bigger screw type caps? I hope someone can enlighten me .
Thank you.
I think the screw-terminated caps are designed for much higher and constant ripple current. The PC-mounted caps have made a lot of progress over past few decades in packing in a lot of capacitance, but they may have a lower current rating. Check the operating temperatures.
Caps can be rated by performance.
Higher ESR can inhibit current flow and cause self heating. Ripple voltage rating determines how effective the cap is as a line filter. (see frequency rated at). Service life is determined by how much excess chemical is packed in, plus how much outgasses out through the holes and caps edges sealed with what quality of sealant?
So caps of very different sizes can have similar performance. Or caps that are physically big can have shorter life because the sealant was low grade. Read the numbers. Vendors newark (farnell) and digikey have a fairly complete list of specs in the selector table. Others refer you to the manufacturer datasheet. Some vendors won't even tell you what vendor and what line of cap they are selling. I don't use the latter for anything more than a throwaway prototype, and there are plenty of used caps around to equip those, so why buy a *****y 500 hour cap anyway?
Screw terminals were popular in the 70's and early 80s, are still sold now but at a very high premium price over "snap in" caps. I've converted my gear with original screw terminal caps to the snap in, but learned due to a bad experience that wires soldered on need a board of some sort to strain relieve the wire in case the solder melts. In my case, the whole amp was hot enough to melt solder, then the cap wire lifted off, touched the top, and blew up the feeding parts. An insulating board with 4 holes, two of them for the snap in terminals, two for loops of wire, glued on the cap with weatherstrip adhesive, can make the snap in installation fairly secure. Also, since the clamps that screw the screw terminal cap to the case don't fit anymore, I glue snap in caps to the chassis also with weatherstrip adhesive.
Best of luck in your replacement project.
Higher ESR can inhibit current flow and cause self heating. Ripple voltage rating determines how effective the cap is as a line filter. (see frequency rated at). Service life is determined by how much excess chemical is packed in, plus how much outgasses out through the holes and caps edges sealed with what quality of sealant?
So caps of very different sizes can have similar performance. Or caps that are physically big can have shorter life because the sealant was low grade. Read the numbers. Vendors newark (farnell) and digikey have a fairly complete list of specs in the selector table. Others refer you to the manufacturer datasheet. Some vendors won't even tell you what vendor and what line of cap they are selling. I don't use the latter for anything more than a throwaway prototype, and there are plenty of used caps around to equip those, so why buy a *****y 500 hour cap anyway?
Screw terminals were popular in the 70's and early 80s, are still sold now but at a very high premium price over "snap in" caps. I've converted my gear with original screw terminal caps to the snap in, but learned due to a bad experience that wires soldered on need a board of some sort to strain relieve the wire in case the solder melts. In my case, the whole amp was hot enough to melt solder, then the cap wire lifted off, touched the top, and blew up the feeding parts. An insulating board with 4 holes, two of them for the snap in terminals, two for loops of wire, glued on the cap with weatherstrip adhesive, can make the snap in installation fairly secure. Also, since the clamps that screw the screw terminal cap to the case don't fit anymore, I glue snap in caps to the chassis also with weatherstrip adhesive.
Best of luck in your replacement project.
Hi , Thank you for your replies , I already have the chassis and the power transformer, My amp will be dual mono from transformer to output relay , The Power supply is linear but the amp is Class D 250w into 8 ohms per channel , Using 4 10000uf 80v caps for each channel. , But I'm not so technical about caps , So in plain English , My question is , Do I lose nothing if I Choose the cheaper snap in caps over screw types in my amp build?
If the medium power use of the amp, then no loose at all. But if you will take hard duty from it, then the snap in caps will degrade quicklier than screwed counterparts.
Screws were a sign of quality in 1970. From mallory the "computer grade" cap had screws. The Mallory name has been sold off to a vendor that assembles in the country where "concrete" is made of sand and "pork" is made of rat, so screws are not a sign of quality anymore.
Look up the numbers for ESR, ripple factor, service life, of two specific caps you are comparing. Plain english doesn't cut it when you are doing engineering. Numbers do.
If you want names of brands that weren't assembled in the country of institutional fakes, I can be persuaded to talk. I've replaced >300 caps since 2010 , and the only way to find out where things are made is buy them and look at the packing slip.
Look up the numbers for ESR, ripple factor, service life, of two specific caps you are comparing. Plain english doesn't cut it when you are doing engineering. Numbers do.
If you want names of brands that weren't assembled in the country of institutional fakes, I can be persuaded to talk. I've replaced >300 caps since 2010 , and the only way to find out where things are made is buy them and look at the packing slip.
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