I need it for charging batteries

morning

@harvey_slash Search google images for "constant current source". Most of those circuits will provide a constant current until the battery reaches some certain value. Unfortunately, most of them aren't designed with that in mind, so they won't tell you what that value is. But you ought to be able to work it out.

Or just search for "battery charging circuit"

thanks

Hi

@abdullahkahraman ho

Oh, what da? Something happened to my computer!

Only the letter "m" is like this..

Doesn't matter Firefox or IE

?

:'(

@abdullahkahraman did you pay your annoying-bug-defuser-license this month

@abdullahkahraman Looks like the font got changes BTW, that may be site specific (or not).

some non-optimized or non-aliased font

did you fiddle with (sub-pixel) aliasing settings?

@jippie It is not site specific and changing anti-aliasing settings doesn't work. :(

Ah, yes...

Re-installed Verdana font and done! :)

hi everybody

hi

@VladimirCravero hi

@JYelton thanks for pointing out that doubt can not mean question. In Italian it can, my mistake followed.

Where is this @kortuk character when you need him

@jippie What happened to the original "how do I build a power supply?" question?

@ThePhoton What HDIBAPS-question?

He previously posted the same question with 30 V dc input, but that one seems to have been nuclearly annihilated.

Why are people so eager to build power supplies?

I understand that's an underestimated topic in EE, also if (ultra)(very)low power equipment is fancy today, but for a home project I'd just buy a wall adapter

@VladimirCravero It is a good project to learn from.

Yeah that's true

I wonder what that guy must power with all these voltages

@VladimirCravero Because they find the transformer too bulky

(and expensive, but that is secondary)

@jippie yep but you need a transformer somewhere

@VladimirCravero no you don't

an inductor at least? :D

@VladimirCravero I mean, we would need one, but then again we are old fashioned EE that care about safety and power consumption and things like that

or you can use a "capacitive divider" (do they call it like that)

@jippie you are speaking of a switched mode PSU without a transformer?

that would not be insulated for the grid, seems like a bad idea to me

@VladimirCravero usually they aim for resistive dividers or the capacitive divider

@VladimirCravero that is what everybody keeps telling them, but it is the wrong answer.

@jippie I can't follow you

?

you are saying a transformerless dc-dc converter from the recified grid is safe enough?

I can't follow you = I don't understand what you are saying

telling people they mustn't make a non-galvanic separated power supply is a dumb idea is not what these people want to hear.

as in grid connected

Now I get it

I was thinking I was missing a great new kind of power supply

You can always design circuits that run on 350Vdc

@VladimirCravero easy enough

I once "designed" a coilgun

six capacitors from ATX psus running straight from the rectified grid

And once I wanted to design a super high power audio amp and since transformers are $$$ I was thinking to make something out of discrete components running directly from the grid, but luckily I soon found out it was not such a great idea

mainly because they don't make 15kW loudspeakers, where \$15kW=\frac{(350V)^2}{8\Omega}\$

@jippie it seems we have all the flavours tonight: electronics.stackexchange.com/questions/123580/…

> I'm limited to the mains supply in Europe of 230V

:16888792 ..

> Strangely, the polarity is also reversed as I expected

Yes you want that with electrolytics at 300VDC+

We need a darwin

@jippie imho he has the probes reversed on the multimeter.

@VladimirCravero That's what I hope for him.

@jippie he can still go full darwin and move the black probe from the "V-R" connector to the "A" connector

@VladimirCravero I tried to measure amps of mains when I was a young boy ... Nothing really bad happened apart from my multimeter probes get dented.

@jippie well that's DC, and there are the caps... I think the fuse might quite bang

@VladimirCravero I guess you are officially one of the grumpy old farts on EE.SE that everybody is annoyed with, because they always say what you can't do.

Welcome to the league of EE.SE's grumpy old farts.

We need an official plaque for that

@VladimirCravero Fuse? Amp range? Expensive meter that has a fused amp range.

@jippie well thanks, can we just strip the "old" part of the title for now? I still feel young enough for now

@VladimirCravero nope

all part of the deal

@jippie well I'll stick to it then... Any notable companion?

myself?

@AnindoGhosh

not to forget Olin

I guess all regulars with formal training

Even @abdullahkahraman should be allowed to the league

@jippie I must say that telling what you can't do is usually easier than telling what you can't do

huh?

Usually the first thing is to say: Stop doing that

the second thing to say is: before you kill yourself (or others)

and the third thing would be, what you can do

I was just trying to say that there's no need to have formal training, a sort of hey I might be a GOF but I'm no guru

too many sentences and I already stopped reading myself after the first sentence :-p

GOF?

time for bed, have get up early tomorrow morning

ah GOF, I get it

@VladimirCravero Having formal training makes it easier to enter the GOF league :-p

but it is not a requirement

anyways

/me is out

@jippie well I'm almost finished with my formal training so I guess I'll... formally be a GOF soon.

good night

@VladimirCravero you could always get a biology degree too

@ewo

damn the enter thing always gets me

@EwokNightmares I don't think I'd like to study biology, I love human made things guts, not nature made ones

you could specialize in robot genetics

@EwokNightmares Robot paternity tests?

@EwokNightmares I like robots

@W5VO ya i'm sure a thesis needs to be written for that

@EwokNightmares I'm not sure what "robot genetics" is though

With self replicating robots, who's going to pay baby robot child support?

@VladimirCravero that's why you'd get a degree in biology

Ah I'm sorry my thesis will be something about delta sigma ADCs

@W5VO the one with male plugs

@EwokNightmares I was planning to search for a job instead...

maybe a doctorate in biology is the solution, but I bet you need a major in biology for that

someone needs to get a job making LTspice faster

@EwokNightmares You need smaller circuits

or a better time step

what if I want to simulate a .01 Hz oscillator powered by a 1Ghz charge pump

can't you separate the simulations?

@EwokNightmares you should ask yourself if you are over-engineering things.

/night