Transformer insulateing tape?
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From: Jim Thompson on 20 Jun 2010 16:36 On Sun, 20 Jun 2010 06:07:33 +0000 (UTC), Cydrome Leader <presence(a)MUNGEpanix.com> wrote: >Hammy <spam(a)spam.com> wrote: >> On Sat, 19 Jun 2010 22:47:52 +0000 (UTC), Cydrome Leader >> <presence(a)MUNGEpanix.com> wrote: >> >>>Hammy <spam(a)spam.com> wrote: >>>> >>>> What kind of tape can you use for insulation between primary to >>>> secondary of flyback transformer. I know mass produced professional >>>> designs use a 3M specialty tape. What I'm looking for is a tape I >>>> could pick up at Staples or some office supply store or hardware >>>> store. >>>> >>>> The vinyl electrical tape I can find is only rated for 600V and 80C >>>> MAX TEMP. >>>> >>>> Is there a commonly available tape that is good for higher temp and >>>> offers higher insulation? I've read of people using a mylar tape is >>>> there a brand name ,type anyone could recommend? >>>> >>>> This is for a 90 - 140Vac input flyback. >>> >>>are you making one transformer or many, and if so, are you using a coil >>>form? >> >> Just one. I'm using an ETD29 core with Bobbin. I've made several >> transformers for LVDC less then 50Vrms.This is my first transformer >> from scratch for a line powered supply. I usually just buy or get >> samples from places like coil craft, but I want a multiple output >> flyback 50W small light weight and I've got this down too fitting into >> a 5" x 3" x2.2" in enclosure. I know I could buy one for $50 to 100 >> plus but that's no fun;-) >> >> I will be the only one using it. Its main purpose is to save bench >> space and to save me the hassle of having to continually dig out 317's >> 7812 or 7805's when I'm working on something that requires multiple >> voltages. >> >> So its not going to be tested for EMC compliance (but I do have a line >> filter) or Hi Pot tested etc. >> >> I originally did it up to operate of my Bench top PSU with an EFD20 >> core/ bobbin set (for 24W ) but I want to be able to eliminate the >> larger Bench top PSU so I don't have so much clutter on the bench. >> >> Eventually I'll get around to building a half decent sized bench, but >> I just finished installing and painting seven new interior doors. >> That's my renovating fun for a couple of months anyway's. ;-) > >This info helps quite a bit. > >For a single unit you might be able to scavenge the yellow tape from a >junked switching power supply from from a computer. Some peel apart if you >smash the ferrite, some don't. Do avoid plain electrical tape- it creeps >and "pressure" inside a coil with hundreds or thousands of turns can sink >right though it. > >Other sources of insulating material are in your junk pile. Those white >plastic sheets that replace fish paper to keep pins from hitting close >fitting chassies can be cut up and used. Junked computer power supplies >have lots of goodies like this inside them. > >It works fine for quick and dirty projects. secure it with scraps whatever >tape you can peel from a transformer or inductor and you're good. Ask Larkin. He's the resident mouthy non-expert here. Makes AlwaysWrong look like a Nobel Laureate ;-) ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | Where is Joe McCarthy when you need him ??
From: Jan Panteltje on 20 Jun 2010 16:55 On a sunny day (Sun, 20 Jun 2010 13:09:14 -0700) it happened Perenis <Perenis(a)hereforlongtime.org> wrote in <iats16lnv75krd2gcjp7anlkjk730ngve2(a)4ax.com>: >On Sun, 20 Jun 2010 19:33:24 GMT, Jan Panteltje ><pNaonStpealmtje(a)yahoo.com> wrote: > >>On a sunny day (Sun, 20 Jun 2010 15:25:31 -0400) it happened Hammy >><spam(a)spam.com> wrote in <9kqs16p9evdl9lh8ikt3l6uqkg5ecmrnrj(a)4ax.com>: >> >>>> First, he wants quick and dirty to prove the design. Then, he MIGHT >>>>fine tune it, characterize it, or 'dial-it-in'. If it works right on the >>>>first jab, he might just be done with it and get back to his other bench >>>>work. >>> >>> >>>Exactly. >>> >>>Thanks for reading the requirments.;-) >> >>Any mains isolation could be solved by putting windings on separate legs and >>using 2 U cores.... >>Earth the core. >>Safer not possible. > > It is NOT a line transformer! LOL, what do you mean by that? Any switchmode can have windings on different legs, the primary that is connected to the mains on one leg, and any secundary for output on the other You would not go by an other often wrong alias now would you?
From: Wimpie on 20 Jun 2010 17:30 On 20 jun, 21:19, Perenis <Pere...(a)hereforlongtime.org> wrote: > On Sun, 20 Jun 2010 11:53:29 -0700 (PDT), Wimpie <wimabc...(a)tetech.nl> > wrote: > > >He mentions it is line-powered, > > The UNIT is, not the transformer. > Words from Hammy: "Just one. I'm using an ETD29 core with Bobbin. I've made several transformers for LVDC less then 50Vrms.This is my first transformer from scratch for a line powered supply." Did I understand this wrong, no mains powered circuit? > I would feel reasonably sure that the hammster does not need to worry > about his AC flashing through to the operator. Andif it doe, he'll trash > it and build another. > > > so you have to account for over > >voltages and whether single or double/reinforced insulation is > >requried, even when the output voltage is 5V. If Hammy doesn't have EN > >60950, or 60065 at hand, he may search for ECMA-287. > > He has stated SEVERAL times that this is NOT a product! Even when it isn't a product, you want a safe setup. > > > It can be > >downloaded free and gives good guidance on creepage, clearance, > >insulation requirements, etc. > > He knows about that already. SO DO I. The only difference is that *I* > DID read the thread, and *I* DO know what his considerations for this > are. It is for his personal lab. If he knows that (safety issues) already, why asking for what tape to use? > > First, he wants quick and dirty to prove the design. Then, he MIGHT > fine tune it, characterize it, or 'dial-it-in'. If it works right on the > first jab, he might just be done with it and get back to his other bench > work. Wim PA3DJS www.tetech.nl
From: krw on 20 Jun 2010 17:35 On Sun, 20 Jun 2010 20:55:14 GMT, Jan Panteltje <pNaonStpealmtje(a)yahoo.com> wrote: >On a sunny day (Sun, 20 Jun 2010 13:09:14 -0700) it happened Perenis ><Perenis(a)hereforlongtime.org> wrote in ><iats16lnv75krd2gcjp7anlkjk730ngve2(a)4ax.com>: > >>On Sun, 20 Jun 2010 19:33:24 GMT, Jan Panteltje >><pNaonStpealmtje(a)yahoo.com> wrote: >> >>>On a sunny day (Sun, 20 Jun 2010 15:25:31 -0400) it happened Hammy >>><spam(a)spam.com> wrote in <9kqs16p9evdl9lh8ikt3l6uqkg5ecmrnrj(a)4ax.com>: >>> >>>>> First, he wants quick and dirty to prove the design. Then, he MIGHT >>>>>fine tune it, characterize it, or 'dial-it-in'. If it works right on the >>>>>first jab, he might just be done with it and get back to his other bench >>>>>work. >>>> >>>> >>>>Exactly. >>>> >>>>Thanks for reading the requirments.;-) >>> >>>Any mains isolation could be solved by putting windings on separate legs and >>>using 2 U cores.... >>>Earth the core. >>>Safer not possible. >> >> It is NOT a line transformer! > >LOL, what do you mean by that? >Any switchmode can have windings on different legs, >the primary that is connected to the mains on one leg, >and any secundary for output on the other >You would not go by an other often wrong alias now would you? Yes. Terrell better add it to the list.
From: Perenis on 20 Jun 2010 18:57
On Sun, 20 Jun 2010 20:26:01 +0000 (UTC), Cydrome Leader <presence(a)MUNGEpanix.com> wrote: >Archimedes' Lever <OneBigLever(a)infiniteseries.org> wrote: >> On Sun, 20 Jun 2010 06:07:33 +0000 (UTC), Cydrome Leader >> <presence(a)MUNGEpanix.com> wrote: >> >>>For a single unit you might be able to scavenge the yellow tape from a >>>junked switching power supply from from a computer. Some peel apart if you >>>smash the ferrite, some don't. >> >> >> Even if it would, the adhesive is pressure sensitive, and will have >> polymerized, and be unusable for subsequent use, unless you wanted to do >> it without the adhesive. > >the outside wraps, even the ones around the ferrite halfs can sometimes be >peeled off an re-used. the keyword is sometimes. With the *REAL* word being "rarely". |