Re: [time-nuts] Replacing electrolytics - any disadvantages of high temp ones?
Sorry to perpetuate the OT discussion, but there is an excellent series of articles by capacitor design engineer Cyril Bateman called Understanding Capacitors, published in EWWW magazine in the late '90s. The article on electrolytics covers almost anything you might want to know about them, and is a very worthwhile read. I highly recommend the whole series. Cyril had the articles posted on his own website some time ago, which I can no longer find. But, they are still available online if you search around. - Chad. On Jun 23, 2011, at 9:10, Dr. David Kirkby david.kir...@onetel.net wrote: On 06/21/11 08:39 PM, Poul-Henning Kamp wrote: In message4e008a73.50...@erols.com, Chuck Harris writes: and yet, I find that some electrolytic capacitors that have been run at lower than normal voltage improve markedly when reformed by applying rated voltage through a 10K resistor for a couple of hours. I noticed in a datasheet at one point, that the capacity only was warranted above a certain percentage of rated voltage. No explanation was given. Note on the link posted by Robert LaJeunesse: http://www.cde.com/catalogs/AEappGUIDE.pdf it says voltage derating gives better reliability: == Aluminum electrolytic capacitors made with formation voltages at least 35% higher than rated voltage and with rated tempera- tures of 85 oC or higher, don’t require much voltage derating. In applications operating at less than 45 oC no derating is needed, and with up to 75 oC, 10% is sufficient. For higher temperatures and with high ripple current, 15% or 20% is appropriate. Since operating life continues to increase for further derating, military and space applications use 50% voltage derating. I've herd stories one should not operating caps well below their rated voltage, but that would tend to suggest that is not so. -- A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Replacing electrolytics - any disadvantages of high temp ones?
Hi Chad: Google found it: http://techdoc.kvindesland.no/radio/passivecomp/20061223155312558.pdf But it's not that informative. The best info I've seen on measuring components is the HP (Agilent) Impedance Handbook. http://cp.literature.agilent.com/litweb/pdf/5950-3000.pdf I measured dozens of caps using a number of different methods to see how well the combined ESR and Capacitance meter I sell works. http://www.prc68.com/I/ESRmicro.shtml http://www.prc68.com/I/Capacitors.shtml Does anyone know of a modern cap leakage tester? Have Fun, Brooke Clarke http://www.PRC68.com GMail / AnalogAficionado wrote: Cyril Bateman called Understanding Capacitors ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Replacing electrolytics - any disadvantages of high temp ones?
Sencor LC 102. -John == [snip] Does anyone know of a modern cap leakage tester? Have Fun, Brooke Clarke http://www.PRC68.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Replacing electrolytics - any disadvantages of high temp ones?
Hi Brooke that is only the last of about 5 or 6 articles in the same journal you need to find the others as well. Cyril used to work for one of the big UK manufacturers I believe. I think I still have the paper copies of EWW somewhere. Alan G3NYK - Original Message - From: Brooke Clarke bro...@pacific.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Friday, June 24, 2011 7:22 PM Subject: Re: [time-nuts] Replacing electrolytics - any disadvantages of high temp ones? Hi Chad: Google found it: http://techdoc.kvindesland.no/radio/passivecomp/20061223155312558.pdf But it's not that informative. The best info I've seen on measuring components is the HP (Agilent) Impedance Handbook. http://cp.literature.agilent.com/litweb/pdf/5950-3000.pdf I measured dozens of caps using a number of different methods to see how well the combined ESR and Capacitance meter I sell works. http://www.prc68.com/I/ESRmicro.shtml http://www.prc68.com/I/Capacitors.shtml Does anyone know of a modern cap leakage tester? Have Fun, Brooke Clarke http://www.PRC68.com GMail / AnalogAficionado wrote: Cyril Bateman called Understanding Capacitors ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Replacing electrolytics - any disadvantages of high temp ones?
Hi John: It's almost $1k and does much more than measure leakage. Is there a much lower cost instrument that's aimed at just leakage? Have Fun, Brooke Clarke http://www.PRC68.com J. Forster wrote: Sencor LC 102 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Replacing electrolytics - any disadvantages of high temp ones?
Hi again John: The manual for the LC 102 is free from BAMA and it's got all kinds of useful info. http://bama.edebris.com/manuals/sencore/lc102/ Have Fun, Brooke Clarke http://www.PRC68.com Brooke Clarke wrote: Hi John: It's almost $1k and does much more than measure leakage. Is there a much lower cost instrument that's aimed at just leakage? Have Fun, Brooke Clarke http://www.PRC68.com J. Forster wrote: Sencor LC 102 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Replacing electrolytics - any disadvantages of high temp ones?
Hi Brook, I know it's a pricey box, but I got mine cheap ($100) at an MIT Flea Market. If I wanted a cheapo leakage tester, I'd build one with a simple, variable voltage inverter, maybe a Cockroft-Walton stage or so, and a couple of $20 DMMs. -John = Hi John: It's almost $1k and does much more than measure leakage. Is there a much lower cost instrument that's aimed at just leakage? Have Fun, Brooke Clarke http://www.PRC68.com J. Forster wrote: Sencor LC 102 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Replacing electrolytics - any disadvantages of high temp ones?
Yes, except the schematics suck. Dave H at ArtekMedia helped mo out with that. You could also get the manual from Sencor directly for something like $20 - $50, I forget exactly. The LC 102 has been replaced with the LC 103, last seen. -John = Hi again John: The manual for the LC 102 is free from BAMA and it's got all kinds of useful info. http://bama.edebris.com/manuals/sencore/lc102/ Have Fun, Brooke Clarke http://www.PRC68.com Brooke Clarke wrote: Hi John: It's almost $1k and does much more than measure leakage. Is there a much lower cost instrument that's aimed at just leakage? Have Fun, Brooke Clarke http://www.PRC68.com J. Forster wrote: Sencor LC 102 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Replacing electrolytics - any disadvantages of high temp ones?
All, Speaking of replacing electrolytic capacitors, which I am now doing on a Fluke 845A, I found a carbon comp resistor way out of spec. It is a 150 ohm, 1/4 watt current limiter, for a 10 Vdc zener. I noticed that it had looked to have been hot (or gave off excessive heat), and had made a shiny place on the PC board above it, though the resistor doesn't show any burnt color. When I measured it, it was reading around 1 to 2 ohms. The zener was still good, luckily, as was the bridge rectifiers, and filter cap (though bulged), and this is the supply voltage for the switching transistors, which run the chopper transformer. My question is, have any of you seen a 150 ohm carbon comp resistor change that much in value? I wouldn't think they could, but evidently, this one did, and if so, I wonder about the others in the meter. Thanks, Will *** REPLY SEPARATOR *** On 6/24/2011 at 11:22 AM Brooke Clarke wrote: Hi Chad: Google found it: http://techdoc.kvindesland.no/radio/passivecomp/20061223155312558.pdf But it's not that informative. The best info I've seen on measuring components is the HP (Agilent) Impedance Handbook. http://cp.literature.agilent.com/litweb/pdf/5950-3000.pdf I measured dozens of caps using a number of different methods to see how well the combined ESR and Capacitance meter I sell works. http://www.prc68.com/I/ESRmicro.shtml http://www.prc68.com/I/Capacitors.shtml Does anyone know of a modern cap leakage tester? Have Fun, Brooke Clarke http://www.PRC68.com GMail / AnalogAficionado wrote: Cyril Bateman called Understanding Capacitors ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. __ Information from ESET Smart Security, version of virus signature database 5851 (20110206) __ The message was checked by ESET Smart Security. http://www.eset.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Replacing electrolytics - any disadvantages of high temp ones?
Sencore 102 or 103's. If your lucky you can find one for less $200. If you don't mind the age. At the bottom of the pile are ones like the Eico 950-B and many that are close. The 950-B is about the best in the lower shelf. Stick with the B, newer if anything and remember Eico's also came as a kit. If you not in a rush, wait till you find a Sprague Tel-Ohmike's The 5 and 6's being the last of the series and the only ones to really consider. Just my call, others like some of the older ones. Depending on condtion and phase of the moon you can get a TO-6A for around $50, most go for about $100. Next shelf up I would say the Clough-Brengle 712 and its military cousin the ZM-11/U. I find it harder to use only in that everything is jammed so close. And my 712 died a couple years ago and havn't got around to looking inside. Price $50 to $100 Non of these prices reflect Ham-fests, Aunt Milli's thrift store etc. All the above will or should be gone over, the usual stuff caps, resistors, etc. The one I use the most is the Tel-Ohmike 6A. Some say the 5 is better and the 6's did dropped the transformer ration feature, but I only the thing i use it for is caps. Moving into the modern era, the Sencore's 75, 102 and 103. Again at the top Sencore 102 and 103's, but you really have to be lucky to get one under $100 or so. I've not been so lucky. On Fri, Jun 24, 2011 at 11:22 AM, Brooke Clarke bro...@pacific.net wrote: Hi Chad: Google found it: http://techdoc.kvindesland.no/radio/passivecomp/20061223155312558.pdf But it's not that informative. The best info I've seen on measuring components is the HP (Agilent) Impedance Handbook. http://cp.literature.agilent.com/litweb/pdf/5950-3000.pdf I measured dozens of caps using a number of different methods to see how well the combined ESR and Capacitance meter I sell works. http://www.prc68.com/I/ESRmicro.shtml http://www.prc68.com/I/Capacitors.shtml Does anyone know of a modern cap leakage tester? Have Fun, Brooke Clarke http://www.PRC68.com GMail / AnalogAficionado wrote: Cyril Bateman called Understanding Capacitors ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Replacing electrolytics - any disadvantages of high temp ones?
On Fri, 24 Jun 2011 11:11:34 -0700, GMail / AnalogAficionado analogaficion...@gmail.com wrote: Sorry to perpetuate the OT discussion, but there is an excellent series of articles by capacitor design engineer Cyril Bateman called Understanding Capacitors, published in EWWW magazine in the late '90s. The article on electrolytics covers almost anything you might want to know about them, and is a very worthwhile read. I highly recommend the whole series. Cyril had the articles posted on his own website some time ago, which I can no longer find. But, they are still available online if you search around. - Chad. . This site has links to many of Cyril Bateman's articles, including the EW series on capacitors. http://www.proaudiodesignforum.com/forum/php/viewtopic.php?f=6t=153start=2 -- kc0ukk at msosborn dot com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Replacing electrolytics - any disadvantages of high temp ones?
Yes, that's the one... As Alan mentions there are several other articles, and I see the same website has them - just lop off the file name at the end of the URL to see the rest. Here's the one specifically on electrolytics: http://techdoc.kvindesland.no/radio/passivecomp/20061223155301644.pdf - Chad. On Jun 24, 2011, at 11:32, Alan Melia alan.me...@btinternet.com wrote: Hi Brooke that is only the last of about 5 or 6 articles in the same journal you need to find the others as well. Cyril used to work for one of the big UK manufacturers I believe. I think I still have the paper copies of EWW somewhere. Alan G3NYK - Original Message - From: Brooke Clarke bro...@pacific.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Friday, June 24, 2011 7:22 PM Subject: Re: [time-nuts] Replacing electrolytics - any disadvantages of high temp ones? Hi Chad: Google found it: http://techdoc.kvindesland.no/radio/passivecomp/20061223155312558.pdf But it's not that informative. The best info I've seen on measuring components is the HP (Agilent) Impedance Handbook. http://cp.literature.agilent.com/litweb/pdf/5950-3000.pdf I measured dozens of caps using a number of different methods to see how well the combined ESR and Capacitance meter I sell works. http://www.prc68.com/I/ESRmicro.shtml http://www.prc68.com/I/Capacitors.shtml Does anyone know of a modern cap leakage tester? Have Fun, Brooke Clarke http://www.PRC68.com GMail / AnalogAficionado wrote: Cyril Bateman called Understanding Capacitors ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Replacing electrolytics - any disadvantages of high temp ones?
If I recall, didn't BK make a capacitor analyzer that did ESR measurements too? I think it was a hybrid, part solid-state, and part tube, but folks swore by them. Best, Will *** REPLY SEPARATOR *** On 6/24/2011 at 2:34 PM Pete Lancashire wrote: Sencore 102 or 103's. If your lucky you can find one for less $200. If you don't mind the age. At the bottom of the pile are ones like the Eico 950-B and many that are close. The 950-B is about the best in the lower shelf. Stick with the B, newer if anything and remember Eico's also came as a kit. If you not in a rush, wait till you find a Sprague Tel-Ohmike's The 5 and 6's being the last of the series and the only ones to really consider. Just my call, others like some of the older ones. Depending on condtion and phase of the moon you can get a TO-6A for around $50, most go for about $100. Next shelf up I would say the Clough-Brengle 712 and its military cousin the ZM-11/U. I find it harder to use only in that everything is jammed so close. And my 712 died a couple years ago and havn't got around to looking inside. Price $50 to $100 Non of these prices reflect Ham-fests, Aunt Milli's thrift store etc. All the above will or should be gone over, the usual stuff caps, resistors, etc. The one I use the most is the Tel-Ohmike 6A. Some say the 5 is better and the 6's did dropped the transformer ration feature, but I only the thing i use it for is caps. Moving into the modern era, the Sencore's 75, 102 and 103. Again at the top Sencore 102 and 103's, but you really have to be lucky to get one under $100 or so. I've not been so lucky. On Fri, Jun 24, 2011 at 11:22 AM, Brooke Clarke bro...@pacific.net wrote: Hi Chad: Google found it: http://techdoc.kvindesland.no/radio/passivecomp/20061223155312558.pdf But it's not that informative. The best info I've seen on measuring components is the HP (Agilent) Impedance Handbook. http://cp.literature.agilent.com/litweb/pdf/5950-3000.pdf I measured dozens of caps using a number of different methods to see how well the combined ESR and Capacitance meter I sell works. http://www.prc68.com/I/ESRmicro.shtml http://www.prc68.com/I/Capacitors.shtml Does anyone know of a modern cap leakage tester? Have Fun, Brooke Clarke http://www.PRC68.com GMail / AnalogAficionado wrote: Cyril Bateman called Understanding Capacitors ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. __ Information from ESET Smart Security, version of virus signature database 5851 (20110206) __ The message was checked by ESET Smart Security. http://www.eset.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Replacing electrolytics - any disadvantages of high temp ones?
Hi: Be careful, the web URL is Pro Audio Design Forum. There are other cap articles by the same author where he's measuring the distortion at 1 kHz down to -140 dB. Have Fun, Brooke Clarke http://www.PRC68.com Matt Osborn wrote: On Fri, 24 Jun 2011 11:11:34 -0700, GMail / AnalogAficionado analogaficion...@gmail.com wrote: Sorry to perpetuate the OT discussion, but there is an excellent series of articles by capacitor design engineer Cyril Bateman called Understanding Capacitors, published in EWWW magazine in the late '90s. The article on electrolytics covers almost anything you might want to know about them, and is a very worthwhile read. I highly recommend the whole series. Cyril had the articles posted on his own website some time ago, which I can no longer find. But, they are still available online if you search around. - Chad. . This site has links to many of Cyril Bateman's articles, including the EW series on capacitors. http://www.proaudiodesignforum.com/forum/php/viewtopic.php?f=6t=153start=2 -- kc0ukk at msosborn dot com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Replacing electrolytics - any disadvantages of high temp ones?
On 06/21/11 08:39 PM, Poul-Henning Kamp wrote: In message4e008a73.50...@erols.com, Chuck Harris writes: and yet, I find that some electrolytic capacitors that have been run at lower than normal voltage improve markedly when reformed by applying rated voltage through a 10K resistor for a couple of hours. I noticed in a datasheet at one point, that the capacity only was warranted above a certain percentage of rated voltage. No explanation was given. Note on the link posted by Robert LaJeunesse: http://www.cde.com/catalogs/AEappGUIDE.pdf it says voltage derating gives better reliability: == Aluminum electrolytic capacitors made with formation voltages at least 35% higher than rated voltage and with rated tempera- tures of 85 oC or higher, don’t require much voltage derating. In applications operating at less than 45 oC no derating is needed, and with up to 75 oC, 10% is sufficient. For higher temperatures and with high ripple current, 15% or 20% is appropriate. Since operating life continues to increase for further derating, military and space applications use 50% voltage derating. I've herd stories one should not operating caps well below their rated voltage, but that would tend to suggest that is not so. -- A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Replacing electrolytics - any disadvantages of high temp ones?
Oh to add further information. I love old caps. They go bad and I get my test equipment for cheap. That said I do measure the caps I am going to put in on a old style HP cap meter that can apply up to 100 volts to the cap. I look for leakage. What I see in quite modern caps that have been around for a while (Surplus you get at hamfest approx 3-5 years) is that there is a higher leakage current that does settle down after a while. So I sense the forming effect still exists. Am I wrong about this?? Regard Paul WB8TSL On Wed, Jun 22, 2011 at 1:16 AM, Chuck Harris cfhar...@erols.com wrote: Hi Bill, I agree with your forming information, as applied to older caps, but not your temperature information. The 105C high temp caps are just as happy, or unhappy really, with low temperatures as the 85C caps. Basically the difference between the two is water. The 85C caps have an electrolyte with a significant amount of water, that boils dry at high temperatures. The 105C caps don't. Kind of like the difference between an antifreeze and water solution, and straight antifreeze. Both seriously run out of capacitance when they get below freezing. The loss of capacitance can really bite you when you use integrated low overhead voltage regulators in automotive temperature ranges. The regulators will oscillate if they don't have enough capacitance on their input terminals... which can happen if you specify an electrolytic capacitor that is right around the 100uf needed. When it gets to 0C, and becomes a 10uf capacitor, the regulator takes off and burns up your load. -Chuck Harris Bill Hawkins wrote: Group, During my days of interest in antique radios, I learned that the dielectric between aluminum plates was formed by passing current in one direction to build up an oxide coating on the plates, which became the dielectric. The thickness is directly proportional to working voltage and inversely proportional to capacitance. As we learned from reforming old caps, the oxide thins when there is no voltage on the cap, but can be restored by passing several milliamps through the cap. Applying rated voltage before it was formed would destroy the cap by welding spots of the plates together. I'm not sure that this applies to modern caps. As to the temperature rating, a high temp cap run in a cool environment will be as unhappy as someone transplanted from Miami to Minneapolis in the winter. It may work, but it will be very unhappy - so it depends on your empathy for the cap. There ought to be a way to work precision time into this thread, but I can't think of one. Bill Hawkins -Original Message- From: Poul-Henning Kamp Sent: Tuesday, June 21, 2011 2:40 PM In message4E008A73.50701@erols.**com 4e008a73.50...@erols.com, Chuck Harris writes: and yet, I find that some electrolytic capacitors that have been run at lower than normal voltage improve markedly when reformed by applying rated voltage through a 10K resistor for a couple of hours. I noticed in a datasheet at one point, that the capacity only was warranted above a certain percentage of rated voltage. No explanation was given. __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Replacing electrolytics - any disadvantages of high temp ones?
IMO, the issue of reforming is very much alive with electrolytics, old and new. In some modern PZT actuator drivers, there is a warning to bring up the supplies slowly if the unit has been dormant for sx months or more. -John Oh to add further information. I love old caps. They go bad and I get my test equipment for cheap. That said I do measure the caps I am going to put in on a old style HP cap meter that can apply up to 100 volts to the cap. I look for leakage. What I see in quite modern caps that have been around for a while (Surplus you get at hamfest approx 3-5 years) is that there is a higher leakage current that does settle down after a while. So I sense the forming effect still exists. Am I wrong about this?? Regard Paul WB8TSL On Wed, Jun 22, 2011 at 1:16 AM, Chuck Harris cfhar...@erols.com wrote: Hi Bill, I agree with your forming information, as applied to older caps, but not your temperature information. The 105C high temp caps are just as happy, or unhappy really, with low temperatures as the 85C caps. Basically the difference between the two is water. The 85C caps have an electrolyte with a significant amount of water, that boils dry at high temperatures. The 105C caps don't. Kind of like the difference between an antifreeze and water solution, and straight antifreeze. Both seriously run out of capacitance when they get below freezing. The loss of capacitance can really bite you when you use integrated low overhead voltage regulators in automotive temperature ranges. The regulators will oscillate if they don't have enough capacitance on their input terminals... which can happen if you specify an electrolytic capacitor that is right around the 100uf needed. When it gets to 0C, and becomes a 10uf capacitor, the regulator takes off and burns up your load. -Chuck Harris Bill Hawkins wrote: Group, During my days of interest in antique radios, I learned that the dielectric between aluminum plates was formed by passing current in one direction to build up an oxide coating on the plates, which became the dielectric. The thickness is directly proportional to working voltage and inversely proportional to capacitance. As we learned from reforming old caps, the oxide thins when there is no voltage on the cap, but can be restored by passing several milliamps through the cap. Applying rated voltage before it was formed would destroy the cap by welding spots of the plates together. I'm not sure that this applies to modern caps. As to the temperature rating, a high temp cap run in a cool environment will be as unhappy as someone transplanted from Miami to Minneapolis in the winter. It may work, but it will be very unhappy - so it depends on your empathy for the cap. There ought to be a way to work precision time into this thread, but I can't think of one. Bill Hawkins -Original Message- From: Poul-Henning Kamp Sent: Tuesday, June 21, 2011 2:40 PM In message4E008A73.50701@erols.**com 4e008a73.50...@erols.com, Chuck Harris writes: and yet, I find that some electrolytic capacitors that have been run at lower than normal voltage improve markedly when reformed by applying rated voltage through a 10K resistor for a couple of hours. I noticed in a datasheet at one point, that the capacity only was warranted above a certain percentage of rated voltage. No explanation was given. __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Replacing electrolytics - any disadvantages of high temp ones?
A very good reference for aluminum electrolytic use: http://www.cde.com/catalogs/AEappGUIDE.pdf Guides for other capacitor types are also on this page: http://www.cde.com/appguide/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Replacing electrolytics - any disadvantages of high temp ones?
Had not seen these links and at least so far the CDE sights quite good Thanks On Wed, Jun 22, 2011 at 12:35 PM, Robert LaJeunesse rlajeune...@sbcglobal.net wrote: A very good reference for aluminum electrolytic use: http://www.cde.com/catalogs/AEappGUIDE.pdf Guides for other capacitor types are also on this page: http://www.cde.com/appguide/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Replacing electrolytics - any disadvantages of high temp ones?
On 06/21/11 12:59 AM, Alan Melia wrote: David Another important factor when considering power supply caps is ripple current rating. It is generally the ripple current that makes them get warm. Yes. I must admit I did not give that any thought, which was rather stupid of me. But I did not buy cheap caps. I will check the ripple ratings, but its hard to know exactly what is needed. I think the usual thumbnail calculation still work for caps if you can reduce the temperature by 20 degrees they will last at least 4 times as long. That is an activation energy (Arrhenius eqn) of about 1ev. I also believe though I cant quote that they are best run at about 75% of their specified working voltage. I have always wonderd about this but it would seem to be a mistake to have too low a voltage on electrolytics ...maybe something to do with the strength of the instulating layer formed. Yes, I have heard this before about not using them at too low a voltage. I don't know whether its an old-wives tale, or if there is any truth to it. Alan G3NYK Thanks for your comments Alan, Dave G8WRB. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Replacing electrolytics - any disadvantages of high temp ones?
Dr. David Kirkby wrote: I think the usual thumbnail calculation still work for caps if you can reduce the temperature by 20 degrees they will last at least 4 times as long. That is an activation energy (Arrhenius eqn) of about 1ev. I also believe though I cant quote that they are best run at about 75% of their specified working voltage. I have always wonderd about this but it would seem to be a mistake to have too low a voltage on electrolytics ...maybe something to do with the strength of the instulating layer formed. Yes, I have heard this before about not using them at too low a voltage. I don't know whether its an old-wives tale, or if there is any truth to it. It is discussed in ITT's Reference Data for Radio Engineers. It certainly was true at one time not necessarily anymore, though. In the old days, the oxide layer that formed the dielectric was mostly formed in place by applying a controlled current to the capacitor at a voltage above the intended operating voltage. Now, the aluminum electrode foil is anodized before the capacitor is assembled, and the electrolytes are specifically formulated to not damage the oxide layer and yet, I find that some electrolytic capacitors that have been run at lower than normal voltage improve markedly when reformed by applying rated voltage through a 10K resistor for a couple of hours. -Chuck Harris ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Replacing electrolytics - any disadvantages of high temp ones?
In message 4e008a73.50...@erols.com, Chuck Harris writes: and yet, I find that some electrolytic capacitors that have been run at lower than normal voltage improve markedly when reformed by applying rated voltage through a 10K resistor for a couple of hours. I noticed in a datasheet at one point, that the capacity only was warranted above a certain percentage of rated voltage. No explanation was given. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Replacing electrolytics - any disadvantages of high temp ones?
Group, During my days of interest in antique radios, I learned that the dielectric between aluminum plates was formed by passing current in one direction to build up an oxide coating on the plates, which became the dielectric. The thickness is directly proportional to working voltage and inversely proportional to capacitance. As we learned from reforming old caps, the oxide thins when there is no voltage on the cap, but can be restored by passing several milliamps through the cap. Applying rated voltage before it was formed would destroy the cap by welding spots of the plates together. I'm not sure that this applies to modern caps. As to the temperature rating, a high temp cap run in a cool environment will be as unhappy as someone transplanted from Miami to Minneapolis in the winter. It may work, but it will be very unhappy - so it depends on your empathy for the cap. There ought to be a way to work precision time into this thread, but I can't think of one. Bill Hawkins -Original Message- From: Poul-Henning Kamp Sent: Tuesday, June 21, 2011 2:40 PM In message 4e008a73.50...@erols.com, Chuck Harris writes: and yet, I find that some electrolytic capacitors that have been run at lower than normal voltage improve markedly when reformed by applying rated voltage through a 10K resistor for a couple of hours. I noticed in a datasheet at one point, that the capacity only was warranted above a certain percentage of rated voltage. No explanation was given. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Replacing electrolytics - any disadvantages of high temp ones?
Hi Bill, I agree with your forming information, as applied to older caps, but not your temperature information. The 105C high temp caps are just as happy, or unhappy really, with low temperatures as the 85C caps. Basically the difference between the two is water. The 85C caps have an electrolyte with a significant amount of water, that boils dry at high temperatures. The 105C caps don't. Kind of like the difference between an antifreeze and water solution, and straight antifreeze. Both seriously run out of capacitance when they get below freezing. The loss of capacitance can really bite you when you use integrated low overhead voltage regulators in automotive temperature ranges. The regulators will oscillate if they don't have enough capacitance on their input terminals... which can happen if you specify an electrolytic capacitor that is right around the 100uf needed. When it gets to 0C, and becomes a 10uf capacitor, the regulator takes off and burns up your load. -Chuck Harris Bill Hawkins wrote: Group, During my days of interest in antique radios, I learned that the dielectric between aluminum plates was formed by passing current in one direction to build up an oxide coating on the plates, which became the dielectric. The thickness is directly proportional to working voltage and inversely proportional to capacitance. As we learned from reforming old caps, the oxide thins when there is no voltage on the cap, but can be restored by passing several milliamps through the cap. Applying rated voltage before it was formed would destroy the cap by welding spots of the plates together. I'm not sure that this applies to modern caps. As to the temperature rating, a high temp cap run in a cool environment will be as unhappy as someone transplanted from Miami to Minneapolis in the winter. It may work, but it will be very unhappy - so it depends on your empathy for the cap. There ought to be a way to work precision time into this thread, but I can't think of one. Bill Hawkins -Original Message- From: Poul-Henning Kamp Sent: Tuesday, June 21, 2011 2:40 PM In message4e008a73.50...@erols.com, Chuck Harris writes: and yet, I find that some electrolytic capacitors that have been run at lower than normal voltage improve markedly when reformed by applying rated voltage through a 10K resistor for a couple of hours. I noticed in a datasheet at one point, that the capacity only was warranted above a certain percentage of rated voltage. No explanation was given. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Replacing electrolytics - any disadvantages of high temp ones?
I'm sure many of you with old equipment must have considered the fact that electrolytic caps have a finite life and considered replacing them. I have a few that look suspect (bulging) on a transceiver, and decided to replace them. I'm tempted to do all of them in the PSU, as: * It runs hot * PSU could destory other bits * Two of the 15 or so caps on the PSU board show signs of bulging. For the PSU I used all 105 deg C caps, apart from one which was rated at 125 deg C. These are higher spec than the originals. I also replaced another cap (not in a hot region) with a 105 deg C rated cap. I've made my capacitor choice based on assuming. 1) Higher temperature devices (like 105 deg C) will be more relieable than low temperature ones like the standard 85 deg C cap. I'm sure at high temperatures, that must be true, but I've no idea if it would be beneficial if the cap does not get very warm. 2) There are no disadvantage of the higher temperature caps, other than cost. Are these true? I've ruled out the idea of replacing all electrolytics with new ones. That would be a LOT of work, and cost a lot of money. Dave -- A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Replacing electrolytics - any disadvantages of high temp ones?
In message 4dffbaf4.4070...@onetel.net, Dr. David Kirkby writes: 1) Higher temperature devices (like 105 deg C) will be more relieable than low temperature ones like the standard 85 deg C cap. I'm sure at high temperatures, You should check both temperature and lifetime rating of the capactors. There are many capacitors on the market these days with 5000h or even 2000h rated life. That is 7 or 3 months respectively. And yes, it should be criminal to manufacture and sell those. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Replacing electrolytics - any disadvantages of high temp ones?
On 06/20/11 10:44 PM, Poul-Henning Kamp wrote: In message4dffbaf4.4070...@onetel.net, Dr. David Kirkby writes: 1) Higher temperature devices (like 105 deg C) will be more relieable than low temperature ones like the standard 85 deg C cap. I'm sure at high temperatures, You should check both temperature and lifetime rating of the capactors. I have, but I would assume one rated at 6000 hours at 125 deg C would be at least as good as one rated at 7000 hours at 105 deg C. There are many capacitors on the market these days with 5000h or even 2000h rated life. That is 7 or 3 months respectively. Even 1000 hours I've seen. But these are of course at the maximum temperature, which few would use them at. Otherwise failure rates would be a lot higher than they are. I've not seen any electrolytics rated more than 10,000 hours (14 months), but they last a lot longer if the temperature is lower. My PC is already more than 14 months old, and has been on 24/7. Hopefully it is not dying on me. And yes, it should be criminal to manufacture and sell those. Well, I think the MTBF will be a lot more than that in practical use, as few would design equipment to run at 85 deg C, which is the lowest maximum temperature rating I've seen on any cap. -- A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Replacing electrolytics - any disadvantages of high temp ones?
David Another important factor when considering power supply caps is ripple current rating. It is generally the ripple current that makes them get warm. I think the usual thumbnail calculation still work for caps if you can reduce the temperature by 20 degrees they will last at least 4 times as long. That is an activation energy (Arrhenius eqn) of about 1ev. I also believe though I cant quote that they are best run at about 75% of their specified working voltage. I have always wonderd about this but it would seem to be a mistake to have too low a voltage on electrolytics ...maybe something to do with the strength of the instulating layer formed. Alan G3NYK - Original Message - From: Dr. David Kirkby david.kir...@onetel.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Tuesday, June 21, 2011 12:40 AM Subject: Re: [time-nuts] Replacing electrolytics - any disadvantages of high temp ones? On 06/20/11 10:44 PM, Poul-Henning Kamp wrote: In message4dffbaf4.4070...@onetel.net, Dr. David Kirkby writes: 1) Higher temperature devices (like 105 deg C) will be more relieable than low temperature ones like the standard 85 deg C cap. I'm sure at high temperatures, You should check both temperature and lifetime rating of the capactors. I have, but I would assume one rated at 6000 hours at 125 deg C would be at least as good as one rated at 7000 hours at 105 deg C. There are many capacitors on the market these days with 5000h or even 2000h rated life. That is 7 or 3 months respectively. Even 1000 hours I've seen. But these are of course at the maximum temperature, which few would use them at. Otherwise failure rates would be a lot higher than they are. I've not seen any electrolytics rated more than 10,000 hours (14 months), but they last a lot longer if the temperature is lower. My PC is already more than 14 months old, and has been on 24/7. Hopefully it is not dying on me. And yes, it should be criminal to manufacture and sell those. Well, I think the MTBF will be a lot more than that in practical use, as few would design equipment to run at 85 deg C, which is the lowest maximum temperature rating I've seen on any cap. -- A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
