PWM power supply

Shoudn't it be 25%?
Current is not controlled here, resistance (aka the soldering iron) and voltage are.
Power = Voltage ^ 2 / Resistance. Double the voltage, that quadruples the power. So you only want to plug in 25% of the time to get the equivalent power of 120V.
But it might not melt at double power? Maybe the extra heat helps, I can't find a resistance/temperature curve for a soldering iron...
Source: EE dropout.
- nnnNNEEEEEEERRRRRRRRRd!
- Right you are. Oops.
  
  If only the oop was here to see this 😔
- Ok. I was acountless on lemmy for a long time, your comment made me finally register. Thanks!
  So, yeah, with double the voltage you get 4x the power. But you you put 4 times the power at 50% of the time, you get only 2x the power. And the other half of the time, you get 0 power. On the average you get the same power output.
  
  You double counted there.
  You said 4x power 50% of the time and then said “the other half of the time.”
  So you’re calculating 50% of 50% which is 25% duty cycle.
  
  Also, welcome to Lemmy!
  
  I had to think about it too, lol. This is an equation for DC/instantaneous power, and if you want to get into AC math, this is more like a square wave. Averaging the power out over time doesn’t necessarily work with the equation, as you figured out, as it doesn’t when you try to measure AC (sinusoidal) power by average voltage or whatever.
- I sure hope someone will be fired for this obvious blunder
  
  If my company fired people for trade show cock-ups we would change the entire staff every couple months. There is a lot of stuff being moved in a short time period, shit is stressfull and you're working at a diminished capacity at least a week aferwards. As long as the stand is not on fire during the show, all is good.

Finally, an usecase for USB irons!
- I just got one, and it’s so practical with a PD battery bank. Can now solder inside or outside on my car/bike with zero hazzle
  
  I love my Pinecil. I recommend them to kids as a beginner iron cause of the low price and sleep function.
  
  I have one too, I like the idea of it but can't solder with it. For any serious work I use my old transformer iron that has enough power to melt the solder.

It's only stupid if it doesn't work
- And vice versa
  
  Yeah! "It's only doesn't work if it stupid." 🤷‍♂️ I've always said that...

Should have just left it in, and been able to get the soldering done twice as fast.
- New manufacturing hack unlocked: Install 240v outlets at workstations and fire half of the workforce. Golden parachute and douchey, hand-wavey TED Talk, please!
  
  Elon knows more about manufacturing than any other person on earth, he said

There are gas powered soldering irons that are essentially lighters with metal around the flame. Real life savers
- There are also battery powered soldering irons.
  
  I like the pinecil, usb-c powered soldering iron with temperature control. If you are not doing anything intensive any fast smartphone charger will power it.
  
  yes but that sounds boring and doesn't require having a functionally super-hot piece right near a reserve of acetylene.
  
  Yes, and they actually have a working thermostat, so they aren't complete garbage to solder electronics with.
  Gas powered soldering irons are great for soldering stuff like copper water pipes. But even soldering through-hole components with them is a pain in the ass due to the temperature instantly evaporating all your flux. Soldering SMD components is near impossible with them

there's the STEM bell curve. XKCD shows the axes as 'how well your computer works' vs 'how well you know computers'. that is accurate.
but if you've ever known serious engineers who didn't just live boring white collar work-home-work-and-some-marvel-shit lives, you'll have seen things that make this look mild.
edit: and it gets really crazy when you're talking about a civil engineer. closest thing you'll ever find to an eldritch location.
- xkcd.com/1785
  
  I think there's another one, where the right side references operating systems, and another without the graph that's along similar lines. long runners sometimes return to the same wells, I guess.
- Link?
  
  no, sorry; I'm profoundly lazy.

I've had a similar experience as a child. I live in Germany and found this voltage switch on a hair dryer. My thoughts were like: Switching it to less couldn't possibly hurt, could it? Well it could. It was super efficient though but only for a few seconds before it self destructed.

Don't they have switches?
- No.
  Seriously, many soldering irons don't have a switch. Fancy soldering stations have switches, temperature dials, etc. But basic ones are just a resistive load wired directly to the plug.
  
  I think they meant on the wall or outlet not the iron.
- Sounds like a cheap portable soldering iron, which just heats up to some roughly usable temperature whenever it's plugged in.
  
  Textbook definition!
- Ive seen some really cheap irons that have zero controls, you plug them in and they operate at max power. Basically a wood burning pencil, really.
  An engineer that has a project to show off at a trade show will have will have both a power switch and a temperature control on their soldering iron.
  
  I'm an engineer that's been in that sort of situation. If it's planned, you have the tools. Unfortunately, sometimes these things happen and it's not planned. At that point it's taken what you can get. A cheap fire stick will still do the job better than no fire stick.
- I've only seen outlet switches in the UK, unless you plugged into a roof lamp outlet where the switch are by the entrance door, but then you need a plug like these (at least here in sweden)
- Every one i've owned has and I get the cheap ones. I guess you can find them for under a dollar or something

Hey. If it works, it works.
Any port in a storm right?

They need a 1/4 duty cycle.

Person Wait Modulation.

I had the opposite problem, I brought a soldering iron from Europe to Canada, and despite using a step up transformer, it just couldn't get hot enough to melt the solder!
- You should have used 200% duty cycle
  
  Splice on a second plug, so you can use two outlets at the same time.
  (/s, mostly... this can actually work, if you can find two outlets on opposite phases.)

Reminds me of the time when I helped install some 120 VAC ceiling fans and the electrician* wired them to the 220 VAC line. They spun like a helicopter trying to take off.
*Worked for the local electric utility, we trusted him, foolishly.

Why plug and unplug? Doesn't the wall outlet have a switch?
- I have actually never met a wall outlet with a switch.
  
  Really? Where are you for that? I don't have a wall outlet without a switch, and I've never seen one because why would it just be live all the time?
  I'm in Australia for reference.
- Afaik it is a safety thing that is handled differently in different countries.
  Uk and their colonised countries have this. The reason is that the fuses are in each plug. But no (or almost no) fuses in the power grid of the house. In Europe most countries have a single GFCI and several fuses for power grid sectors in a single place in the house where the power comes in.
  I assume the switches on the power outlets are for turning off a switch because there is no GFCI in the house.
  
  I think in the UK at least this view might be a little outdated - every house I've ever lived in has had GFCI sectors across the house, or had to be updated to have it when work was done.

So we've officially gone meta around here lol, we did it Lemmy!

Sounds super safe.

I hope this is a bs story for clout, you can buy universal power converters at airports.
- Don't those just make the plugs fit? Isn't that the point of the story?
- Universal power adaptors change pin configuration but not voltage.

Because the plug would fit the outlet, right?
- There are a bunch of adapters you can buy that don't convert voltage, and it's pretty common for people to buy them by mistake.
  
  and it's pretty common for people to buy them by mistake
  Or even on purpose, for the many things that don't care (a lot of electronics, where it has a rectifier, are fine with 110-250V, 50-60Hz)
- If someone knows how to solder, a different shaped plug isn't a big obstacle to them