### Ohm's law?

So, i have a broken soldering iron, and i want to fix itcan someone =smart= calculate the required resistance of wire at 120v aci don't care about the amperage, as long as its under 2 ampsplease give me a range of resistance, i don't like to trip fuses, (my parents hate that!)

Topic by Sandisk1duo   |  last reply

### USA explosive laws

I suggest an 'ible about USA laws and case law regarding the production and use of explosives. there are always comments about this in the explosive 'ible 's and it would be great to clear some of it up.

Topic by smithy813   |  last reply

### is ohm's law applicable in transformer or not?

In a step up transformer we step up the votage and reduce the current but ohm"S law say V=IR or voltage is directly proportional to current then howz it possible ?

Question by    |  last reply

### Should I make an Instructable for this?

Haha, I was already going to make it. I'm just super excited about it so I wanted to share a sneak peek with y'all. I made it out of PVC and metallic paint, mostly, then the usual Steampunk bits and pieces. Then I decided it needed to be lit up with LEDs for special effect! Then I decided it needed a laser sight! Win.

Topic by V-Man737   |  last reply

### I need help in understanding faradays law? Answered

So this is where i was trying to understand his law, http://www.6pie.com/faradayslaw.php, the part that i got stuck was on where it says, "Lets figure 5 turns per second, that gives us 300 RPM. If we do a good blade design we might be able to get 300 RPM in 3 to 5 mile winds. 5 turns per second gives us one turn every .2 seconds seconds = .2" I am trying to apply this to a bike and want to know how to get past this step to getting Δt of the formula.

Question by diabloboy   |  last reply

### You asked for it!

Topic by Kiteman   |  last reply

### Modifying a Singing Greeting Card

A while ago my wife got one of those singing Hallmark greeting cards. (This particular one played the Law and Order theme song) Well after a while it no longer played the song. I opened it up and found that there is a circuit board inside with a 3v button cell battery attached to it. I removed the board and the speaker and the battery and I'm pretty sure that I could attach wires to the two contact points and connect them to batteries that would complete the circuit and allow the theme song to play again. What I want to know is if I need to take any special consideration when putting in a new battery(s). I was going to try to just put two AA batteries in series (1.5v +1.5v =3v, right?) but I don't actually know anything about electronics and so I wanted to ask here if there were any resistors needed or if there were any differences between the button cell and the AA batteries that would require me to do something different.While we're on the topic of these cards I just thought of a neat project. Design some sort of holder for the circuit boards that would allow them to act as sort of an interchangeable cartridge. Basically detach the speaker wires and battery contacts from various boards out of various cards and design some sort of holder with contacts for the speaker and power source at the appropriate points and be able to change out the different boards. Not really practical but sounds like fun.I just thought of yet another question!Would there be anyway to hook the board up to some sort of audio cable (in place of the speaker maybe) so that I could plug these into a computer and record the song off of the board in a digital format. (Again not very practical but sounds like fun.)Anyway, this is my first post here and I'm sorry if it's a bit jumbled but I don't have a very organized mind and sometimes it's hard to put my ideas down in a succinct manner. I tend to just ramble on incessantly in a train of thought sort of manner until I think that I've said what I think I wanted to say. In closing, I like this site and plan to be around for a while and learn as much as I can. If somebody would like to help me with these ideas/projects I would be happy to provide pictures of the circuit board and pieces that I have if it's necessary.Thanks.~JoshI'm using two AA batteries. I have a wire between the positive side of B1 and the negative side of B2 and wires coming off the open ends. I tried connecting the batteries from the spot where the negative side of the button cell was to the silver rectangle thinking that that would complete the circuit and make music. That didn't work. Then I noticed that the positive connection for the circuit was actually where the clip that secured the battery was before I removed it and that the positive and negative sides of the battery were going through a capacitor before touching the final contact. so I tried placing the positive wire up on the positive contact and then placing a wire from the positive contact to the final contact but that also didn't work. I don't have any solder and have been using electrical tape to secure the wires. The wires are a fairly thin (I don't know the gauge) stranded copper. I'm not sure if the wires aren't making good contact or if I'm just doing something wrong.

Topic by MrKltpzyxm   |  last reply

### hw in the hel wud i bild a machin to reverse the spin of the earth by some kinda lenzs law method and destroy the earth

Question by yaantey   |  last reply

### can i replace any battery(s) with any other battery(s) as long as the total voltage is the same? Answered

9v are commonly used in a lot of projects, but 150mah give or take isn't a lot. since they're nothing but 6 aaaa and ohms law is v = ir, then couldn't u use 6 aa instead of a 9v for any project? also could u use different battery chemistries? i have no idea about that one because it would definitely change the overall esr and although most battery esr's are very low, i don't know what would happen if u changed it even a little.

Question by the judge   |  last reply

### Double-post on Flickr and Instructables?

I just posted some pictures and a short description of a new project on Flickr, and I was wondering if it is considered acceptable to post it here with the same pictures and description. I'm aware of Kiteman's law, but does it apply to double-posting on two different sites? Thanks, Noahh Update: I decided to post. Here it is.

Question by noahh   |  last reply

### Infinity divided by 0?

Does infinity divided by zero theoretically equal any number other than 0 or infinity? I heard something about ohm's law applied to a circuit with an ideal voltage source (which is only theoretically possible) and having the terminals shorted out and at 0 ohms, resulting in the current going up to infinity?

Question by .Unknown.   |  last reply

### physics mini potato spud gun homework help

Im a grade 11 n i need to write an essay about mini spud gun, but i dun reli understand the physics theory behind it? i search it thr the internet n is now more confused? which one(s) of these is it involved with?>> Projectile Motion Newton's 1st Law of Motion: Inertia Newtons 2nd Law of Force and Acceleration Newton's 3rd Law of Motioin: Action and Reaction Momentum Energy he Boyle Law or the Kinetic Theory of Gases?? why? thanks so much! im not askin like for ppl to do my hw, i juz wanted to know which one of those is a potato gun involved wif.thanks!

Topic by babyduck   |  last reply

### Right to Information-still a right to gain in Bangladesh

Bangladesh gained independence twice. From the British for the first time and second time from Pakistan. Unfortunately Bangladesh inherited the black laws made both by the British and the PAKISTANI. It is more unfortunate the politician like to those black laws when they are in power. Bangladeshi citizens could asked for infprmation from a government office.  But there is also the light of hope. The government passed RTI-Act 2009 in 2009 to ensure people's right to information. Though the government officer are not interested to supply information as per the law, it is at leat a start. To know more you can see the news http://www.thedailystar.net/newDesign/news-details.php?nid=211710

Topic by sunil_123

### Help with a Bel Air Bantam sewing machin?

I need threading directions for a 1950's Bel Air Bantam sewing machine. I have tried every combination I can think of and the tension is way off and the thread ends up breaking. My Angel Mother in law has alzheimers and cannot remember how to use the machine. Any suggestions?

Question by laNell   |  last reply

### Hoax? A task not only for high-schoolers...

Well, exept for being quite a fun thing to watch, it also should work as a great Physics problem for someone like me (or a bit younger)-studying all sorts of Mechanics and Newton's Laws to work on... The task is to estimate the acceleration the motorcycle should have to do it, and whether it's significantly larger than the one stated in some technical data (there is the motorcycle model somewhere in the video's name).        If you have a go on it and are a) school-aged and b) not sure you are right, PM me. If you simply want to share your results and/or opinion, write here (but try not to put any solution-I mean formulas). In case the video doesn't work

Topic by gruffalo child   |  last reply

### Component Amperage Rating

Hi! I was browsing through an electronics retailer website looking for components to buy (particularly a LED) and i was wondering what the amperage rating of each component meant Does it mean: 1. the current flow across this component shouldn't be more than the amperage rating as it will cause damage? 2. or the current flow across this component should be equal to this amperage rating? please help me I'm really confused :(

Topic by La Tour Rouge   |  last reply

### How to make a DIY relatively long distance radio signal emitter/tracker? Answered

Hi, This is a bit of a two-parter. The first part is that I would like to make a DIY radio emitter that could transmit to a distance of 1km. I'm not sure about the laws in South Africa, but it should be legal if within the ranges prescribed by the law. The second part is that I would like to create several devices that could track the nearest radio signal on a specific band or band range (as I would expect that I would have to use a filter for both the transmission and receiving). I think that direction of the source of the signal would be sufficient.  The reason for this is that I have had a few instances over the years where people got lost while camping and had to sleep in the wilds because it was too dark to find their way back to camp. Any advice, thoughts, links would be much appreciated. Also, if you have any other ideas that will cost about the same or less, that would be awesome to try out, too :) Best regards, Vuur

Question by Vuur   |  last reply

### The Secret Service is Calling Me! Help!!

Hi Friends,Recently someone has been calling me on my cell phone about 3 times a day saying they are the secret service from a private Caller ID. It is someone from my high school. I think they are using a spoof card because the phone number is blocked or the white houses number. It is really starting to piss me off and I need some help. They have called about 7 or 8 times in the last 2 days. Its really annoying. I called sprint to see what they could do but all they said was that I would need to contact local law enforcement to put it to a stop. The worst part is they are not only wasting there own and my own time but they are also working away at my phone bill. So, I need your help. What do you think I should do, contact the local police and get the perpetrator(s) arrested for impersonating a government member or should I try something else such as taking the law into my own hands (phone trap/ back spoofing)Thanks for all your help.Joe Rowley

Topic by joejoerowley   |  last reply

### Win the first multimaterial 3D printing pen!!

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### Official Rules, Stamp It Challenge

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### Official Rules, Scoochmaroo Weekly Challenge: Potatoes

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Topic by noahw

### lbp working games console

helleo i have made 2 working games consoles on lbp i am going to talk about the seconed one it is the sgr 30 it is called this because s is my gamer tag scenscoff91 sg is a game and computer  group i started for my freinds on lbp r stands for rainbow it is in their because games are in full coluor and i didnt want to call it spectrum in case id break a copy right law . 30 because thats how many images a cartirige can hold . check it out please if people want to im ofering to show people how to make their own games on lbp if you want to know how and me on psn my psn name is scenscoff91 no caps or spaces it uses cartrige to hod data serously games arnt that good yet but their beter than the first ones please check it out

Topic by KNEXFRANTIC   |  last reply

### Using a USB port as a power supply to mess with electronics

Hi everyone. Over the past few years Ive been wanting to get around to messing with electronics. Ive learned basic things like ohms law and super basic circuits...(led,resistor,power supply) however i dont learn well with TEXT TEXT TEXT, but rather doing it and finding out what happens. So I have a ton of electroncs laying around which I rip apart and pull components out of.  Today I stuck a tiny 5v, 0.5w fan into my USB on the + and - and had it turn on... Anyone know what else I can screw around with? I would rather do this than use batteries and such. I need a funner way to learn electronics :S Any help please? Fun projects? Thanks

Topic by imagxz   |  last reply

### Official Rules for zazenergy's challenge: Halloween Cupcakes

Topic by zazenergy