mcarterbrown.com  

General Chat MCB's Coffee House: Pull up a seat, and grab your favorite caffeinated beverage. Non-paintball related chat within.

Reply
 
Thread Tools
Old 10-04-2017, 10:54 AM   #11 (permalink)
No Effects, just cooler
 
nofxkid2005's Avatar
 
Join Date: Nov 2008
Location: Vancouver

Also, wanna be scared by useable amperage? Look up suggested amperage settings for Carbon Arc Gouging.. or even just settings for running 5/32 7018 welding rod.
__________________
->"Behind The Mask" Paintball Documentary<-

-Dealings Feedback-
Proudly Playing For:
Wookie Dicks
Lucha Cabras
nofxkid2005 is offline   Reply With Quote
Old 10-04-2017, 10:54 AM   #12 (permalink)
Active Member
 
Join Date: Jun 2016

Quote:
Originally Posted by NYKNIGHT01 View Post
Geeeeez. And I thought I'd never see the power triangle here!!!
Simply put. Think of this. A battery. Has voltage but where is it going? Current is the flow. Voltage is the power behind that flow.
Back to the water. The aforementioned bucket of water holds five gallons. But until u pour it. Put a hole in it or a tube for the water to go some where...the five gallons stay there. Voltage.
Put a hole in it. The five gals will flow out...a bigger hole. Faster flow. Current.
The relationship of the volts and the current create power. But volts and current as everyone has stated ...are different. .
He started it with the bucket idea haha. But that did make sense to me. It was about 3 am when i figured it out. I all of a sudden said "wait, they are also talkin about a battery IN a circuit so if there was a switch, the voltage is still chillin in the battery because its POTENTUAL energy!" Then i figured what they ment. See i came from a 4 year math program right over to applied math which everything gets turned around haha.

Thanks all yall for the awesome posts. I have enjoyed reading them.

Sent from my SM-S920L using Tapatalk
LT72884 is offline   Reply With Quote
Old 10-04-2017, 11:02 AM   #13 (permalink)
Active Member
 
Join Date: Jun 2016

Quote:
Originally Posted by nofxkid2005 View Post
Also, wanna be scared by useable amperage? Look up suggested amperage settings for Carbon Arc Gouging.. or even just settings for running 5/32 7018 welding rod.
SMA is also high current as well. Wait you already said that haha. I loved my welding class. I miss it

Sent from my SM-S920L using Tapatalk
LT72884 is offline   Reply With Quote
Old 10-04-2017, 11:09 AM   #14 (permalink)
MCB Member
 
paintzapper's Avatar
 
Join Date: Jul 2009
Location: Central FL

I was going to bust out my old AC/DC text books (if I can find em now) and scan in some examples that helped me but more than enough information posted on this thread

Keep in mind, theoretical/fundamental formulas and practical application are different. V = IR equation does not factor in all aspects of what actually is happening but gets you damn close.

Would that 9v battery kill you? If you have ever touched a 9v battery to your tongue and "shorted" it across the saliva in your mouth you would know that no it wont kill you but it will feel funny.

Also, keep in mind electricity will put more current in the path of least resistance. Example of this is found while comparing 2 parallel resistors of different values, they will have the same potential (voltage) across them but the resistor of lower value will have more current flowing through it than the one of higher value.

Now the example of a 9V shorted by a wire killing you, consider this information as well. The human skin, when dry, has a resistance around 1k to 100k ohms. When wet it is obviously lower. The internal resistance of the human body is 300 to 1k ohms, so it isn't a short as we would imagine being made of 70% water. If you touch a near 0 ohm wire shorting 9V battery with a skin of 1k ohms (parallel connection), most of the current will not even enter your body. You will register the heat and say "friggen A!" as you notice the singed skin starting to blister a bit.

Back to your tongue, lets assume it has an excessively low resistance of 100 ohms, apply I = V/R here. V/R => 9v / 100 ohms = 0.09 amps. I would assume 300 ohms is more plausible (stick some meter probes on your tongue and see what you get) giving you 0.03 amps.



In reference to short and open.
Short is two connections connected together - think shortest possible path. If other components are connected in parallel to your short, you will have to factor in how they will be effected. Again, parallel paths have the same potential, but the current is divided.

Last edited by paintzapper; 10-04-2017 at 11:20 AM.
paintzapper is offline   Reply With Quote
Old 10-04-2017, 11:12 AM   #15 (permalink)
Memento mori.
 
Finnigan's Avatar
 
Join Date: Jul 2006
Location: NJ. Exit 77

Brass and Wood Fan
Kilt Club
Quote:
Originally Posted by Blue64 View Post
Pmed you.
but can also be phase to phase or phase to neutral
It sounds like he is just learning the basics of DC circuits. I'd go easy on the AC talk for a while.
Finnigan is offline   Reply With Quote
Old 10-04-2017, 11:21 AM   #16 (permalink)
Active Member
 
Join Date: Jun 2016

Ok, lets talk bout this 9v battery thing. Yeah touchin across toungue is always fun

Now when i use a small wire to short, the amps would be like 900 or even higher haha.

Yes, just starting electronics. However, i do have linear alg and calc 3 all done so i do have an understanding of sin waves but when aplied to ac, we have not hit that chapter yet haha.



Sent from my SM-S920L using Tapatalk
LT72884 is offline   Reply With Quote
Old 10-04-2017, 11:30 AM   #17 (permalink)
Memento mori.
 
Finnigan's Avatar
 
Join Date: Jul 2006
Location: NJ. Exit 77

Brass and Wood Fan
Kilt Club
I think batteries are limited in how many amps they can deliver per second by/ or due to design. You also have to consider the gauge of the wire. larger wire can handle more current. I believe wire resistance is rated by the foot.

You could calculate it out, OR... you could just test the circuit with an ammeter! Knowledge requires experimentation! Be safe though. Don't short a battery if you can help it. It's a bad idea. if the shorting wire is too small it will heat up and possibly melt (which is basically what an incandescent light bulb is BTW. a shorted wire in a vacuum so it burns up very slowly.) if it is big enough to handle the current it is possible the battery will heat up an leak, or maybe just discharge.
Finnigan is offline   Reply With Quote
Old 10-04-2017, 11:36 AM   #18 (permalink)
MCB Member
 
Grendel's Avatar
 
Join Date: Apr 2006
Location: Northbridge [Whitinsville], MA

Quote:
Originally Posted by paintzapper View Post
...Would that 9v battery kill you? If you have ever touched a 9v battery to your tongue and "shorted" it across the saliva in your mouth you would know that no it wont kill you but it will feel funny...
Voltage doesn't kill it is current and DC current of ~ 0.2 A is potentially fatal, because they can make the heart fibrillate.
  • 1-5 mA is the level of perception
  • 10 mA is the level where pain is sensed
  • 100 mA severe muscular contraction occurs
  • 100-300 mA electrocution occurs
__________________


"Rather fail with honor than succeed by fraud." -Sophocles

My Pyre #PY008 RF Oak Grendel's Feedback on MCB Pyre Serial Number List
Grendel is offline   Reply With Quote
Old 10-04-2017, 11:46 AM   #19 (permalink)
Active Member
 
Join Date: Apr 2016
Location: Houston, TX

Neat, now I know who to bother since I'm finally going back to school for EE and maybe CE.

Quote:
Originally Posted by paintzapper View Post
Also, keep in mind electricity will put more current in the path of least resistance.
And electrons repel each other, so electricity will tend to travel along the outermost part of a path, if resistance is equal overall or whatever.
That's why magicians don't die when doing the ten jillion watt cage trick.
__________________
Ebay Feedback

MCB Feedback
YBBPI is offline   Reply With Quote
Old 10-04-2017, 12:06 PM   #20 (permalink)
MCB Member
 
paintzapper's Avatar
 
Join Date: Jul 2009
Location: Central FL

Quote:
Originally Posted by Grendel View Post
Voltage doesn't kill it is current and DC current of ~ 0.2 A is potentially fatal, because they can make the heart fibrillate.
That is a number I didn't have in my head and is good to know

Quote:
Originally Posted by YBBPI View Post
And electrons repel each other, so electricity will tend to travel along the outermost part of a path, if resistance is equal overall or whatever.
That's why magicians don't die when doing the ten jillion watt cage trick.
Yep! Electrons typically travel on the surface of a conductor, more surface area more flow! A friend of mine has a chainmaille top he uses as a sort of faraday cage that allows him to shoot lightning from his finger tips with his funky contraption!
paintzapper is offline   Reply With Quote
Reply

  mcarterbrown.com » General » General Chat

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Forum Jump


All times are GMT -4. The time now is 08:38 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO
© MCB Network LLC