Electrical Engineering

10:56 AM

@PlasmaHH Why you can never work from home.

https://t.co/LJflckUBCE

Tweeted by inthemoodfortw on February 27, 2017 at 10:49 AM

3:17 PM

3:33 PM

@PlasmaHH Der Empfänger war beim 1. Zustellversuch nicht anwesend. Ein 2. Versuch erfolgt.

Curious how I can narrow this question?

3

A: Compact DC/AC converter

Embedding a Walwart inside your project box seems like a retrograde step. More sensible (and already suggested) is to use power supply products designed to go into project enclosures. If you want to go in this direction you take on a whole lot of responsibility if you intend to sell product. If ...

The short version is "Would this component work as a compact power supply?" Not sure how much narrower I can make it.

As usual, voting to close without providing a comment with a reason is stupid and useless.

3:53 PM

@Asmyldof I blame the wife, her responsibility to stay home ^^

@PlasmaHH o.O

I'm sure leaving a Daughter in charge will be fine for a 29kg package

@AndyD273 You ask whether something would work for you, by providing none of the details needed to judge whether it would. As some answers indicate most people suppose the device you indicate won't work, because you are probably not looking to build your own SMPS with a controller module, which that is. But how the hell can we judge and suggest if we know none of the requirements other than "Smaller than an unnamed and unreferenced wall adapter"

@Asmyldof That's fair (and also why a comment to that effect would have been useful so I could fix it)

And also why I'm here asking how to fix it

JRE

@Asmyldof Paid.

4:11 PM

@JRE Yay. Your package needs to travel further, though both went through the same hub at the same time in Germany, first delivery tomorrow

@AndyD273 I'm not saying everyone else in that Q-chain acted in the spirit of the site, but generally EE is difficult enough when you know the specs, such that a "management type" request quickly falls on deaf or dumb ears here

@Asmyldof I'm still learning my way around, and also what different components do. I added some details. I don't know if that makes it any better

like for instance, this: digikey.com/product-detail/en/VSK-S15-5U-T/102-2608-ND looks like one of these: digikey.com/product-detail/en/cui-inc/VSK-S1-5U/102-2595-ND/… with some screw terminals attached. Does it actually need a lot more stuff to make it into a functional AC/DC converter?

4:46 PM

@AndyD273 Do you want a thing that you solder on to your pcb, or do you want a thing that hooks up with wires to your pcb?

@AndyD273 Do you know how much current your load will need?

on board would be fine with me.

@AndyD273 The first unit you linked says "15 W" and the second one says "1 W", so I don't think they're the same.

@AndyD273 That said I'm using something like the first one (but 50 W) on my current project and it seems okay.

Around 5V. One of the applications is a relay, which has a 5V coil. The other part will be something like an ESP8266

@AndyD273 How much current?

The wallwart I'm currently using is 220mA

@ThePhoton Yeah, I saw that. It was mostly an example of what I'm hoping for. Something compact

4:50 PM

@AndyD273 The only think about soldering on to your pcb is you will need to understand creepage and clearance distances (you can google it) to make the pcb design safe. Also choose a connector to bring the mains voltage on to the pcb.

We should advance from using plain old electricity to something more advanced that doesn't throw away the majority in conversion losses...

Maybe I don't know enough yet to handle this project yet. :/

@AndyD273 5 V @ 200 mA is 1 W, so even the smaller one "should" be okay.

@PlasmaHH donkeys

photons...

@ThePhoton The wasted energy is pretty high on those

4:53 PM

@AndyD273 If you could just train another donkey to muck out the stable, though.

@AndyD273 Or, if the intended application is "garbage disposal", get a goat instead of a donkey.

@ThePhoton Right. I'm looking at the data sheet to see what I need. Test configuration looks like a couple caps for current smoothing, and the "typical application" has a lot more...

All this makes me wish I could take some DC transformers plans back so that Edison could have won the power wars instead of Tesla. To be fair, I would give Tesla the patents.

@AndyD273 Take them back from where?

@ThePhoton Time travel

IIRC, during that time period we had AC transformers, but not DC transformers, so Edisons idea of running DC power everywhere wouldn't work because either the current would be way to high, or you'd need a power station on every block. AC worked because they could run it at high current, and reduce it at substations for household use, which is what Tesla advocated.

As is, we run AC everywhere, and then mostly convert it to DC power at a loss

You know, I have an LED nightlight that somehow manages to turn AC power into DC to run an LED and fits it all into a very small package. I really aught to take that apart and see what kind of current it has...

@AndyD273 Problem is, we still don't have DC transformers.

So you're going to need to go to the future first to get the plans, and then back to the past to get them to Edison.

@AndyD273 Look around for "off-line" power supply designs. The trade-off is no safety isolation.

5:11 PM

Huh. Interesting. For some reason I though we had ways to step down current from very high to low. my bad.

k

High-voltage direct current

@AndyD273 We have, but they're not (AFAIK) called transformers. And Edison would have a hard time doing anything with the plans, since there was no purified silicon (along with a lot of other things) available to him to make the ICs.

A high-voltage, direct current (HVDC) electric power transmission system (also called a power super highway or an electrical super highway) uses direct current for the bulk transmission of electrical power, in contrast with the more common alternating current (AC) systems. For long-distance transmission, HVDC systems may be less expensive and suffer lower electrical losses. For underwater power cables, HVDC avoids the heavy currents required to charge and discharge the cable capacitance each cycle. For shorter distances, the higher cost of DC conversion equipment compared to an AC system may still...

Not to mention the fact that we then would all be stuck with a single phase DC distribution system, which would suck for losses

JRE

5:41 PM

@AndyD273 That's "high voltage.". You generate AC at high voltage, so that you have a lower current for the needed power. Lower current means lower losses over long distances. You transport the AC at high voltage until it gets close to where it is needed, then use a transformet to bring it down to a more easily handled voltage. Now you need more current for the same power, but the losses are acceptable because the distance is shorter