115/230V voltage switch key for transformer?
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From: who where on 25 Nov 2009 19:01 On Tue, 24 Nov 2009 20:44:49 -0800, Joerg <invalid(a)invalid.invalid> wrote: (snip) >I could cook up an electronic auto-selector but that would probably blow >the cost target as well. If you do go that route, beware the brownout on a 240V supply. Kills auto-select ATX PSU's.
From: Joerg on 25 Nov 2009 19:58 Fred Bartoli wrote: > Joerg a �crit : >> Fred Bartoli wrote: [...] >>> Have a dual 120V primaries xfrmer with a relay switched >>> series/parallel connection. >>> The relay rest position is connecting the xfrmer in 240V mode, then >>> you have all the time you need to decide what to do with the relay. >>> Cost: one relay and 10c parts. >>> >>> But I'm confident you'll find something that won't fit ;-) >>> >> >> Yeah, two things :-( >> >> One, a primary side relay adds more than those 10 cents. > > You said 1 buck is OK, not five. > I said one relay and 10c parts. I guess that would not make for 5 bucks... > Probably I could get a DPDT 250V-rated for under a buck but the cap would need to become larger. Then I'd have to convince TUEV and other guys that this is all nice and kosher. > The other is >> that a brown-out situation would cause the relay to partially let go >> ... bzzz ... phssss ... *PHOOMP* >> >> Of course I could make a brown-out detector and all that. But things >> would need to go fast because the transformer is without power during >> the switch-over. >> > > But don't you have a bulk cap somewhere? > Just keep the relay in the same state until the bulk cap voltage is > over. And if you use a low voltage coil WRT to the nominal bulk cap > rail, then you have plenty brownout time before the relay decides to > switch back. > Yes, there is a cap but this all adds parts and stuffing costs. Pretty soon you are over the one buck. > Oh, and it'll never switch on 240 mains, so in not 3rd world countries > we won't experience any failure at all. > Ahem ... I think it was in France where a TV team plugged in some Klieg lights and then the wallpaper turned black from ceiling to wall outlet. Turned out the circuits did not have any fuses and the custodian said "That's normal around here". >> Did you decide which theremin to build with your daughter? >> > > Not yet, but I got some bit of interesting info I didn't think about, > like the one (it's all about ergonomic) that use some "linearizing > trick" to get a usable hand stroke. But I don't like the way they do it > (1000s turns coil). > Also the one you pointed me too was already preassembled. Just fit it in > the box and voil�. That's not what I was after. > But now I begin to feel I've the info I missed to design a good one, so > I might go that path. > > Of course work will get in the way, but... > Don't know how old she is but it might be great to include your daughter in the design process as well. Who knows, maybe she'll catch on to engineering. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: Joerg on 25 Nov 2009 19:59 Baron wrote: > Joerg wrote: > >> petrus bitbyter wrote: >>> <osr(a)uakron.edu> schreef in bericht >>> > news:f664eb19-4b19-4565-b198-87d60393c2a8(a)j19g2000yqk.googlegroups.com... >>> On Nov 24, 8:48 pm, Joerg <inva...(a)invalid.invalid> wrote: >>>> Hello Folks, >>>> >>>> Never needed this before but now I do: What are those things called >>>> that you unplug and insert 180 degrees rotated to switch the >>>> primaries of a transformer between 115V operation (parallel) and >>>> 230V operation (series)? Circuit board mount. >>>> >>>> Or better yet, does anyone know a source? Must be super cheap, as in >>>> <<50c altogether in qties, as usual :-) >>>> >>>> Under categories such as "voltage selector" I only found fuse >>>> holders with this feature in there, really expensive plus way too >>>> large. I want to avoid a slide switch because someone could >>>> accidentally hit it and ... *PHUT* >>>> >>>> -- >>>> Regards, Joerg >>>> >>>> http://www.analogconsultants.com/ >>>> >>>> "gmail" domain blocked because of excessive spam. >>>> Use another domain or send PM. >>> | The classic term used in Marshall and other Audio Amps is voltage >>> | selector plug. >>> | >>> | Somebody decided they should be removed from the electrical code. >>> | Your left with the voltage selecting fuseholders. try schurter. >>> | >>> | Steve >>> | >>> >>> FAIK that old method does not meet current EU safety regulations >>> anymore. So that selectors became obsolete. >>> >>> Why a slide switch will not do? You can find voltage selector slide >>> switches in which the slider is burried so deeply it can only be >>> operated by a small screwdriver or something like that. Sliding it >>> accidentaly seems next to impossible. >>> >> Not that easy anymore. Slide switches often don't have the respective >> agency ratings and since they are primary side they must. Also, it is >> very hard to find any that are rated 260V which is required for >> countries such as the UK. > > Dunno if it helps, I've seen multi pole jumpers used for voltage > selection where the cap has multiple links in it. > Do you remember where or what brand it might have been? -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: Joerg on 25 Nov 2009 20:04 Rich Grise wrote: > On Wed, 25 Nov 2009 12:34:38 -0800, Joerg wrote: >>> BTW, how do you pronounce "Joerg?" :-) >>> >> It's o-umlaut, pronounced just like Archie Bunker and many New Yorkers say >> "poifect" or "point". > > "Joig?" Or maybe "Yoig?" > No, the o-umlaut is like the first part of the French word for "maybe" -> peut-etre Technically one of the "e" needs a roof over there but my keyboard can't do that. > If "Euler" is pronounced, "Oiler," then howcome "Euclid" isn't pronounced > "Oiclid?" ;-) > In German it is :-) -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: Joerg on 25 Nov 2009 20:05
Rich Grise wrote: > On Wed, 25 Nov 2009 14:42:01 -0800, Rich Grise wrote: >> On Wed, 25 Nov 2009 12:34:38 -0800, Joerg wrote: >>>> BTW, how do you pronounce "Joerg?" :-) >>>> >>> It's o-umlaut, pronounced just like Archie Bunker and many New Yorkers >>> say "poifect" or "point". >> "Joig?" Or maybe "Yoig?" >> >> If "Euler" is pronounced, "Oiler," then howcome "Euclid" isn't pronounced >> "Oiclid?" ;-) >> > PS. I was thinking maybe "Yerg". ;-) > > Oops - I think the vodka might be kicking in... > Na'sdarovje! -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. |