Originally posted by: GiLtY
Depending on the resistance of your wire. in a closed DC loop, the Voltage = Resistance * Current. So lower the resistance bigger the current.
Originally posted by: masterxfob
ever stick one on your tongue? hehe, don't lie, i know everyone has tried it before![]()
Originally posted by: Kelvrick
Originally posted by: GiLtY
Depending on the resistance of your wire. in a closed DC loop, the Voltage = Resistance * Current. So lower the resistance bigger the current.
JESUS!! Physics, I have failed you. V=IR, that was one of the formulas everyone should know. Thanks a lot! And I just went and already emailed energizer asking them what their output was.
Originally posted by: Kelvrick
Originally posted by: GiLtY
Depending on the resistance of your wire. in a closed DC loop, the Voltage = Resistance * Current. So lower the resistance bigger the current.
JESUS!! Physics, I have failed you. V=IR, that was one of the formulas everyone should know. Thanks a lot! And I just went and already emailed energizer asking them what their output was.
Originally posted by: Lithium381
Originally posted by: masterxfob
ever stick one on your tongue? hehe, don't lie, i know everyone has tried it before![]()
i haven't, i'm too scared, i heard you get shocked.......though one time when i was little i grabbed an electric fence with both hands and my mom had to tackle me to get me off......maybe that explains it :Q
Originally posted by: Kelvrick
Well, it doesn't matter. Guess I'll be picking up some 200ohm resisters tomorrow at radioshack.
Thread got more replies then I thought. Me going to bed now.
Originally posted by: Kelvrick
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JESUS!! Physics, I have failed you. V=IR, that was one of the formulas everyone should know. Thanks a lot! And I just went and already emailed energizer asking them what their output was.
A battery does not have infinite supply though. Although the electrical equation may make it look like it could draw a lot of amps, the battery may not have the ability to provide that much current with the chemical reaction taking place inside of it.
Originally posted by: GiLtY
Depending on the resistance of your wire. in a closed DC loop, the Voltage = Resistance * Current. So lower the resistance bigger the current.
Originally posted by: Kelvrick
Of course I have. I've also converted a good number to the dark side. Bwahahahaaa
No, but I'm messing with a lighting system and I'd like to not burn out all my leds and such.
Originally posted by: Marshallj
Originally posted by: GiLtY
Depending on the resistance of your wire. in a closed DC loop, the Voltage = Resistance * Current. So lower the resistance bigger the current.
That only works up to a certain point. If you do the equation and put in no resistance (such as a short circuit), it would say that the current draw is nearly infinite. But the battery will not be able to put out that much current.
Let's say he's designing a circuit and he does the equation and find out that it will draw 5 amps. When he plugs the 9v in, the circuit won't work right. Why? Because the battery won't produce that much current. Even with a dead short it will have a upper limit of how much current it can provide.
Originally posted by: So
That's due to the internal resistance of the battery, correct? (or is that just a fiction from high school phys?)
Originally posted by: FenrisUlf
If you regularly read Dan's articles (www.dansdata.com) you will see that he talks about batteries ALOT. A quick search there will probably yield more info about batteries than you ever cared to know. You can probably pull a few hundred mA off of a regular 9v, but remember that they're made up of six smaller cells inside, each only a fraction of the size of a AAA. At that current draw you'll severly compromise its lifespan and might not be able to get the full 9v.
Originally posted by: So
Originally posted by: Marshallj
Originally posted by: GiLtY
That only works up to a certain point. If you do the equation and put in no resistance (such as a short circuit), it would say that the current draw is nearly infinite. But the battery will not be able to put out that much current.
That's due to the internal resistance of the battery, correct? (or is that just a fiction from high school phys?)
Ok, I found some specs and played with the numbers. An alkaline 9v battery has an internal resistance of about 2 ohms. With a voltage of 9 volts and an internal resistance of 2 ohms, if we were to run a the battery in circuit with an LED on it (around 1 ohm), according to the formula the expected current flowing in the circuit would be 3 amps. But it's doubtful that a 9v will be able to produce that kind of current, for the reasons I mentioned above.