I undrestand the charging up part, but don't know what happens when they discharge, is the circuit disconnected or does it just discharge when its full up? I'm very confused, thanks for any help!
206222
they discharge when there is no longer anything charging them. they charge because a voltage is put across them, which causes charges to collect on opposite sides. when the voltage is removed (or short cicuited) there is nothing forcing the opposite charges to opposite sides. the capacitor discharges because opposites attract, and these opposite charges are now free to cancel each other out.
471510
Using someone elses power supply will probably only cause damage if it supplies a higher voltage than your own. You can usually find the voltage rating on the pack itself.\n\nAnd no, leaving the battery in while using the power supply will not damage it. When its fully charged, its stops charging automatically.
298018
Hi,\n\nThis is a RC circuit. And the following is the circuit diagram:\n\nGround --voltage supply --- switch --- R --- C --- Ground\nwhere R is 4.1k Ohm and C is 6uF\n\nFrom the given equation, apparently, the Capacitor is assumed to be uncharged (so voltage across capacitor V_C = 0V) before the switch is closed. When the switch is closed, the voltage across the R is maximum because V_C = 0V. So there is maximum current I_max = (V_supply - 0) /R. However, as the capacitor is charged, V_C increases and thus I reduces. That's why you have this equation:\n\nI = Imax e ^ -( t / RC)\n\nAnd by substituting I = 0.75 Imax, you can find that t = 0.00707 second = 7.07 milli second (ms)\n\nIf you still have more questions, please let us know\nhttp://www.kodkodkod.com/index_files/submitquestion.htm\n\nKodKodKod Learning Consulting
559687
Did u EVER read the ipod guide?\nPlease do so.....\nanyways, when u first plug it in it says "donot disconnect" cuz, its either charging or updating the songs by itself...\nnormally the donot disconnect thing will go after either of these.
10318
NiCads in general electronic applications are typically designed to NOT get hot, since the heat destroys the NiCad battery, can damage electronics and causes lawsuits when users get burned from the hot battery.  Some devices like radio-controlled cars are high-drain applications that generate a lot of heat, so the batteries for these devices are designed for their specific use.\n\nBatteries get hot when they charge due to the high current going into them.  The faster they charge, typically the hotter they get.  When the battery discharges during use, the same thing happens, the battery gets hotter as more current is drawn from the battery.  \n\nWithout knowing anything else, my guess is that high current draw from the battery cells is causing them to heat up.  This can be due to a defective battery, a battery not designed for the way you are using it or your modification damaged the battery or is otherwise causing excessive current drain.\n\nAlso, increasing the supply voltage can drive more current through the device, so it may just be that the higher voltage is drawing more current.\n\nI’m not sure how the device is shutting down, so I can’t say why it’s doing that.  Note that the voltage at which a device stops working is the voltage seen by the device itself.  If you remove the battery from the device and measure the voltage, you will get a different voltage than if you measure the voltage at the precise moment the device shuts down.  This is especially true for high current drain applications, which appears to be what’s happening with your batteries. \n\nPlacing the NiCad’s in the freezer won't help.  They’ll have to warm up to work properly anyway.
661742
man, thats a hard one.... if i were you, i'd look for a charger that will stop charging once the batteries are full. i got one on ebay for about $30 and its made all the difference in the world.
56836
Friction causes the electrical charge. Touch something rubber to kill it. Touch metal to continue the conduction thus shocking yourself or others. Break the curcuit.
114656
I recently read about new power strips that cut even standby power to equipment that are plugged into them. For example, your computer and printer still draw a current even if shut off. this tricle can add up over the course of a year. These power strips cut off that tricle until the moment the unit is roused from standby.\n\nThis was in a pretty good article in this month's Kiplinger's Personal Finance magazine.
640939
Dunno for sure but dont be too hasty on blaming the pute. Go to radioshack and invest in a cheap volt meter, put it on dc volts and measure the voltage at the output of the charger....the charger will tell you what it should be for voltage....sounds more like the charger took a dump to me....it may also be the battery.
506664
Could be a power surge or the card is lose, it came unseated some how, you would know if the card was toast, but is jiggling it does something, try opening it up and see if it has come loose, if not maybe try a new one, but check the dealers in town, maybe if they have a used one to try, just in case it is the board itself, don't spend a lot if you don't need to, the board would be the biggest expence and the card probably might be good and you can use it in thenew unit, if your not sure take in and have a tech look at it, save your self the headaches.
663508
you need to describe what you mean by "small" better.\nis it too small vertically, horizontally, or both?\nAlso, how good is your electronics background?\nDo you know how to discharge the CRT and large capacitors so you don't get zapped with 330 to 10,000 volts while attempting to repair it?\nYou also need to define "wavy" better.\nWith the tin amount of information you have given though, it sounds like the power supply is failing, but in which part is impossible to say.
210815
Well, NiCd and NiMH batteries can be charged and stop charging at full charge without the help of some device to determine if it's full. Once the NiCd and NiMH is full, the current will just pass through and waste your electricity (and if it's left charging at full charge for extended periods, it can also damage the batteries). So it doesn't actually disconnect the current. Just passes through.\n\nBut in Lithium ion batteries, you need some kind of device to determine if it's fully charged. Cellphones, PDA, and iPods kinds of turn on (like, it shows the charging display, but it's not actually on and in your normal thing) when it's plugged into a current so it can detect if it's fully charged. So basically, the device is the mini-computer that determines the charge of the battery.\n\nSo, to answer your question, don't try to create a circuit that will disconnect the current when a Lithium Ion battery becomes fully charged, unless you have the capability, materials, time, and patience to do it. And steady hands. It's really tricky to build a Lithium Ion Battery charger.\n\nPS Penguins!!!
557847
yes, it is a step-up circuit.\nYou can get many volts if you know what you are doing.
86488
Although it is quite possible that nothing noticeable will happen (I have done this hundreds of times without major consequences), you should try to avoid it at all cost. There are three main reasons for this:\n\n1. You will probably lose any unsaved data.\n\n2. It could damage your computer and/or shorten its life.\n\n3. It could cause some files (that HAVE been saved) to be permanently deleted and/or corrupted. Although this is fairly rare, it has happened to me before--and the possible risk is worth serious consideration. All files are at risk; including system files, program files, and all personal files.\n\nSo I suggest that you fix this problem. There are a few different ways you can do this. Your best option is to buy a battery backup system--it should cost you about $25-$45--it will protect your computer from unexpected blackouts as well as it being accidentally unplugged. You could try getting a new surge protector (I assume that is what you mean by an "extention thingy that has a saftey on it")--they are usually about $5, but you can sometimes find them for free with a rebate. However, if you aren't going to get a battery backup, instead of replacing a functional surge protector, I suggest you simply bend the electrical contacts (prongs) outward slightly; this will improve the electrical connection and hold the plug in place.
4079
The power plug is keyed so you can't plug it in wrong.  If it went in correctly you didn't harm it.  If you used the "bigger hammer" method of plugging it in, yep, it's fried.\n\nI've found many stickers on devices that were printed wrong, FYI.
436843
Ok, let's start with the thing it isn't.  It is NOT the battery.  Although that is not to say the battery isn't also bad.  Chances are your A/C Adapter has gone bad and/or the connector inside the laptop(known as the D/C plug) has also gone bad.\n\nYour best bet is to find a local notebook repair shop that can take a look at it and give you a free(or relatively cheap) estimate.  The problem with your description is that there is one major component you've left out...\n\nSoftware.  You'd be surprised, but your o/s could be infected and could actually cause immediate shut-downs.  The question I'd ask is whether or not it shuts down or just IMMEDIATELY shuts off, there is a HUGE difference.  If it shuts down and not off, then it's the o/s and/or software and I HIGHLY recommend taking it into the Geek Squad to have them take a look at it.\n\nIf you have any more information for me I might be able to better evaluate the situation and give you a better answer.  For now, get it looked at by a professional.\n\n-Geek Squad Double Agent...
20757
By Lance Ulanoff  \nImagine a world where all your portable devices can be charged and powered simply by placing them on a desktop. Chip manufacturer MobileWise has gone well beyond imagining such a world and this week unveiled "a conductive solution" that it believes can make it all possible.\n\nDuring a mid-day press conference in chilly New York City, MobileWise showed off a handful of functioning prototype powerbases and retrofitted mobile devices that all use the company's new MobileWise chipset and enable "Wire-Free" electric power. One chip, the tiny Adapter Controller, goes inside the mobile device and the other, the Contact Controller, gets built into the power base station. These power bases, which were shown in a wide variety of shapes, sizes and colors, are each covered in an array of gold-plated contacts. The retrofitted mobile devices also have a pair of contracts. With properly configured handheld devices, the bases can, according to company CEO Andy Goren, change any flat surface into a charging/power station.\n\n \n \n \nThe patent-pending technology behind the MobileWise is, on the surface, quite simple. The adapter chip inside the handheld device will, when placed on a base station, receive a very small electrical signal and message from the base controller chip that will power up the adapter chip. The base controller chip will sense for polarity. If there is none (say you place your hand on the base) then it does nothing. If it does find polarity and then a signal from the adapter chip, it will then read information about the voltage level necessary to run the mobile device and begin charging and powering it. Because of the array of contacts—from dozens to hundreds, depending on base size—there's no need to place the device in a special spot or position on the base. In fact, during the demonstration we saw the bases accept multiple devices, charging and powering them all at once.\n\nThe solution is not actually entirely "wire free", however. The base station is plugged into an AC adapter and can deliver up to 30V DC to an individual device. It's also, according to Goren, completely safe, and if any charge were delivered to a person, it would be at the level of a low-voltage battery, virtually imperceptible to humans and certainly not harmful, he added. The final base units will also, he said, be waterproof and protected from electrostatic charges. \n \n \n\n\nDespite calls for MobileWise to manufacture the bases, Goren said the company plans instead on delivering the chipsets to partners who will likely build the adapter chip and proper contacts into their products and OEM the power base manufacturing to another company. MobileWise showed a variety of colors and form factors for the bases.\n\n \n \n \nAcer has already partnered with MobileWise and, according to Goren, may ship a MobileWise-enabled notebook by Q1 of next year. But MobileWise has, it seems, even more intriguing plans on the horizon. The company is already in discussion with a couple of major office furniture manufacturers to build the power array bases and controller chips into furniture. Apparently, these bases are for more than just mobile devices. Properly-equipped televisions, lamps and more could be powered by the bases—Goren even had an HDTV that worked with one of the larger ones. Later next year, MobileWise expects to add data handshake capabilities to the chipset, allowing, once the signal is split, data delivery over the same contacts.\n\nWhile no shipping units currently exist, MobileWise said the adapter chips run roughly $1.25 a piece adding, it said, just a few dollars in manufacturing costs to mobile devices and the base stations could, in units of 100,000 cost roughly $11 to manufacturers. Goren said he expects a mid-sized base (roughly 12 by 18 inches) to sell for $160 street. Not every mobile device will have to be retrofitted, by the way. MobileWise says it expects to see a ha