Every LED has a current value such as yellow have 10mA and white is 20mA and so on. Each light also has a voltage. And quantity of lights is also imperative to know. Then use the formula
$$R = \frac{ V_{in}-(V_{LED} \times quantity\;of\;LEDs)}{current\;of\;LED}$$
$$R = \frac{4.5<batteries> - \...
It takes a long while before you get any real influence, and if you ask questions worth 2k of rep, then you at the least know how to ask questions properly and I'm fine with someone like that being allowed to edit and vote
There are many more problems with questions than with answers, so having some "experienced experts" in the elites might not hurt
@PlasmaHH Got the laptop back today. Free MB replacement
@Asmyldof yeah, there is like subtle stuff going on in these laws, like after 6 months or so you are required to proof (if necessary) that you receivd a faulty item etc.
starting with a certain length you can do pretty big damages by hitting important parts of the body, especially if you have to inject im :/ that makes things extra scary
a while ago I saw some guy on youtube contemplating about how helpful it would be if all pcb/soldermask was flourescing since he discovered some broken caps that way...
@W5VO it looks that the evaporating electrolyte sometimes alters some of the soldermask chemistry to make it less flourescent. Or just leaves stains that are too faint to see otherwise, whatever hypothesis you follow ;)
@W5VO but a golden badge for just 600 votes? I mean, its nice and shiny and gives me certainly some authority... but then again there was that tranny question from earlier where the user looks similar...
probably some discoloration differences appear due to different heating and depositing of sud due to different airflows, so highly thermally stressed parts might be visible too, regardless of theirmakeup
The only way to get all the blood out of a human in 8 seconds is if you prep with a huge blender and have a centrifuge with a very fine mesh that reaches several thousand RPM within a second or two
@PlasmaHH That was flagged as a dupe by someone under 3k that couldn't vote to close it. The 'possible duplicate' auto-comment gets removed once it's actually closed. Just put a favorite on the question because given the answer would be a good delete vote candidate in a few days for 10k users or now for anyone with 20k.
@Asmyldof 5 liters of blood, with a maximum cardiac output of 35 liters/minute, means that a serious arterial bleed when a conditioned athlete is at max cardiac output (cuz that's who could get there), would be 8.5 second bleed out. of course, cardiac output would go down pretty rapidly starting at time t=0, unless you were replacing the blood with saline as it left.
@Asmyldof Yeah, but it would just be by passive cardiovascular system dynamics, as 8 seconds is pretty fast for autonomic compensation. If you kept volume up, you'd keep bleeding at that volume. Shock wouldn't set in -- no hypovolumic shock, as volume doesn't drop, and no nasty chemical stuff at that time scale. Of course, you'd have to roll over the system a few times to clear the blood, but still under 30 seconds.
What ever you do, you need to replace, which is "slow", or get left with a body containing around 15 to 25% of its original blood content once nothing comes out anymore
In all scenarios where the body is still one entire body (minus at most half an appendage for ease of access)
Hi guys, I'm very new to electronics. I want to make a 7-segment LED clock. I'm unsure how to do this. I have some very custom ideas, like having only 2 digits which show hour/min/sec for only a few seconds at a time when a button is pressed and I also need a 30 min countdown timer. Please, I need some guidance.
@Asmyldof Im sorry, I'm just new. I want to do this for a Design Engineering course, not electronics in anyway. I only have a few days to make a working model but I'm willing to pick up the basics to do it.
@Asmyldof I'll try myself but some direction might be nice. I'm pretty lost.
@Asmyldof I know basic components and soldering. Making a dedicated PCB won't be hard for me if I refer a circuit design online. I just dont know which design I need.
Use google to find out, because I don't know either, because it's not my project
As I said, if you need it quick, your only option is abusing a DIY project already there
For better or worse
I can send you down a path, but I have no idea what other people are doing, because this isn't stuff I do, so you'll just as likely end up a dead end, if you don't just do the searching yourself
Doubtless this site alone has hundreds of questions that contain bits of information you might want, I can simply not say
@PeterJ hmk, was mostly wondering since you reviewed it and close voted too (for whatever reason close votes are not shown in the timeline) which made sense for me only when you voted during the review
and the time of year make us suspicious of students dropping semester projects on us for us to "solve" that they should have been working on / asking questions on.
all right. The "line" on the top is +12 volts near the left and +5 on the right according to teacher / fellow students. what makes it change ? :p no I don't ask you to solve anything lol and it's not a semester project it's named a "mini-project"
The clock on my replacement MB was set to September this year, causing Windows to poop its pants when it was checking for the Win10 update and the server telling it it wasn't allowed to be talking to it
Pooped up the disk and all that, then causing harm to Linux
The negative to the 12V is connected to -5V without any further interference, so basically the schematic claims that wire from the input jack to the regulator somehow changes +7V relative to -5V to +12V relative to -5V
@Magix You have a cell phone in your pocket. It's disconnected from everything, it's powered by a battery. How do you decide what ground is in the cell phone?
"You don't know." This is, I swear, the point to start understanding from. You don't know what potential ground is at, because you don't know what potential anything is at until you can compare it to ground.
@Magix The notion of Ground in a circuit (and I'm not talking about Earth safety ground) is no more than a handy shorthand. You can assign ground symbol to any net in the circuit. You can assign ground to a positive battery terminal if you wish (it may or may not make the schematic easier to understand, but it wouldn't break any physics).
@Magix If we were in the same room, I would be strangling you right about now. Over the years of engineering practice, I have run out of patience for sloppy language along the lines of "something somewhere".
@NickAlexeev Lol I did that to my roommate last night when he was asking me to help him learn AutoCAD, because he got offended at me for saying "No seriously, you have to fill in all these measurements before you draw it."
@Asmyldof That's a philosophical question. I have pressed buttons and watched lights flash which gave me the impression of having "met" you, but this reasoning alone doesn't seem to be rigorous.
@Asmyldof I guess it could be made into a matter of definition, thought I would still take it as a philosophical question as to what "You" or "I" means.
Especially if they are not physical entities and can not use the usual definition of "meeting" as colliding.
So I take it then, me wrapped in a bag of meat is equivalent to me wrapped in a bag of meat wrapped in a tangle of electro-mechanics that spans across the gap to the physical location where you store your meat-wrapper for your own consciousness?
Every LED has a current value such as yellow have 10mA and white is 20mA and so on. Each light also has a voltage. And quantity of lights is also imperative to know. Then use the formula
$$R = \frac{ V_{in}-(V_{LED} \times quantity\;of\;LEDs)}{current\;of\;LED}$$
$$R = \frac{4.5<batteries> - \...
