3.6v 250mAh Ni-MH battery to run 10 5mm LEDs?

I would like to use a rechargeable 3.6v 250mAh Ni-MH battery to directly power 10 5mm LEDs, is that too much mAh?

Question by lifeofB   |  last reply


[help] How to make AA Ni-Mh charger? Answered

Hello! I have one DC Adapter (output 4.5v 500mA) , battery holder , some diod.... I wanna to make a charger which can charge 2AA Ni-Mh at same time.Please help me !!! Thank!! sorry for my bad English

Question by login721   |  last reply


How to, Ni-Cd battery?

Read on the internet, a process that makes old Ni-Cd batteries good again. They say they can resurect old batteries that do not hold a charge. Is this possible? How is it done? Cheers for any help

Question by johnnywgk   |  last reply


Battery pack rejuvenating: What's the best method for rejuvenating a 14.4 volt Ni-Cad battery pack without dismantling?

I have 1 that is getting weak and another that shows 0 volts and won't charge. Neither have had much use. I saw the instructable for individual batteries, but I don't want to have to remove all the batteries and do them individually. Thanks

Question by clswans   |  last reply


Can i create a electronic circuit to handle LED strips like this? Answered

I am trying to create another electronic board that handles LED strips.  I am a newbie, and this is my second build. I tested the circuit but my 10 ohms resistor burnt out. Any advice or suggestions for resistor for this circuit? If i use any resistor 100 ohms + (100, 150, 225, etc) seems to dim the brightness of the LED strips. Should i leave my schematic the same and just use a higher resistor e.g.. 68 ohms or 82 ohms? My LED strips are :- Working Input Voltage: 12VDC. Working Current/meter: 0.4A. Output power: 48W /5 Meter.

Question by islandboii242   |  last reply


Arduino battery 9.6V 650mAh. Help?

I have alot of rc plane Ni-MH recharagables that I dont have a use for since my reciver blew up. Can I run my arduino deumonlative on these batterys they are 9.6V and 650mAh. Also I wold like to know how many mA can I draw from the arduinos 5V supply. Thanks for any help, David.

Question by David97   |  last reply



Why aren't Ni-mh batteries used for electric vehicles? Answered

It seems to me that Lead-acid and Lithium batteries are the only type of batteries used for electric vehicles. Also every one complains that Lead-acid is too heavy and Lithium is too expensive. So why not split the difference and use Ni-mh batteries? They aren't really heavy or expensive. Why aren't they used?

Question by bowmaster   |  last reply


Any ideas making rechargable ni-mh accu ,emergency usb charger for phones,pda etc.?

Any ideas making rechargable ni-mh accu ,emergency usb charger for phones,pda etc ?. it could be the same look like battery charger,thanks

Question by r2r   |  last reply


Battery Charging?

Hello, So I have a 9.6 volt  NI-CD 4 hour quick charger and the battery(600mah) that goes with it, but I was wondering if I could charge a 7.2 volt 2000mah, Ni-Mh battery with it. If i can for how long?

Topic by ben2000   |  last reply


Battery Charging? Answered

Hello, So I have a 9.6 volt  NI-CD 4 hour quick charger and the battery(600mah) that goes with it, but I was wondering if I could charge a 7.2 volt 2000mah, Ni-Mh battery with it. If i can for how long?

Question by ben2000   |  last reply


Can you change the shape of an Ni-Ca battery? Answered

From my experience a battery is a collection of cells; and since Ni-Ca batteries are cased in heatshrink you can see the various cells it is made up of!  As I just bought the wrong battery for my airsoft gun (it is way too big) I thought if I took the casing off and disassembled it into various batteries could you then turn it into a stick battery? May seem obvious; but I'm new to this :) Thanks

Question by Digital Flame   |  last reply


I want to connect a data aquisiton device (NI USB 6009) to a laptop wireless, but dont know how....

I have a data aquisition device from National instruments (NI USB 6009) that connects to a laptop trough a USB cable, and i want to make the connection to the laptop wireless (or via bluetooth), but at the same time i need that the data aquisition device became portable, to install it in a bicicle and receive the data in the laptop... i've put a connection diagram on the image... need help....

Question by NunoMPG   |  last reply


BATTERY help? Answered

i have a rechargeable battery that is 7.2 volts and 3000 mAh Ni-Mh now is it safe to add a Voltage Regulator to run an led or if not how do i? what also is scaring me is the 3000 mAh if its good or bad

Question by MACKattacksnipe   |  last reply


How to Break Solder Tabs On Ni-Cad Battery Pack

So, in a fit of optimism I decided to rebuild a Ryobi One 18v battery pack for my drill. The task seems rather straight forward except that I can't gracefully remove the soldered tabs on top of the batteries that actually make the circuit and connect to the wires.  In the past, I would have removed something like these tabs by either holding the soldering iron to them to melt the solder, slicing the solder with a razor or a combination of the two. These tabs, however, are seriously attached. They won't pry or slice off and the metal of the tab begins to melt before the solder does if I try the iron. I think anymore heat will damage the battery themselves.  Now, it's been a while since I did any electronics work but after a couple of tries I remembered which end of the soldering iron to pickup. I don't think I missed anything. It just seems like these tabs aren't attached with run of the mill solder.  Has anyone had this problem (and found a solution) or am I just missing something blindingly obvious?

Topic by shannonlove   |  last reply


i need a very powerful battery (4000mah 10V or higher) and don't want to spend more then $30 please help! [answered]

I need a  VERY powerful battery (4000mah 12V or higher) and don't want to spend more then $30 please help! and i don't want i Puerkerts number lower than 1.2. can anyone help? oh, and the size of it has to fit in a 6V lantern. thats why lead acids bit the dust and (so far what i know) lithium polymer batteries bit the dust because they are way to expensive. with a 35W power consumption, its hard to find a power source that will fit in a 6V lantern, a affordable price (under $30) and powerful enough to power the load for more than an hour. (some calculations i did show i need at least 3500mah for 1 hour of usage ) but i think i might have a solution a 2 laptop batteries from amazon wired in parallel after they have been took apart. a drill battery doesn't even come close to the amount of i need and they suffer from memory effect and just plain out isn't near powerful enough (1.5 AH per cell) OR my second choice is to get many rechargeable AAA batteries and wire them to give 14.4V (BUT HOW DO I SOLDER THEM WITHOUT THE TABS? and what kind of array should i use? [68 AAA])

Question by -max-   |  last reply


Can I use a 9.6V Ni-MH 650mAh battery with a arduino? Answered

Hi, I have a few batterys from a plane that don't really have a use for anymore. I have been trying to build a rc car but AA's don't supply enough current. I was wonderig if I could use these batterys directley with a duemilanove throug the onboard voltage regulator. They are 9.6V and 650mAh. Thanks for any help. Please leave a commnt. BTW I don't want to draw this much current from the arduino I just want to uer the arduino to cotrol a mosfet. Then run the motor off the battery directley.

Question by David97   |  last reply


AAA/AA batery charger? Answered

Hi guys i want to build batery charger for AAA/AA Ni-Mh bateries and im wondering is there any schematics that can help me?  Thaks a lot :)

Question by JohnSmith-Workshop   |  last reply


DIY Laptop Battery

 I bought a second-hand, cheap laptop but it doesn't have a battery. It's an HP Compaq Presario V6000 series. I don't want to spend on getting a new battery right now. Is there a way I can make a cheap laptop battery out of Ni-Mh cells that I already have? Or, if I get a cheap China made battery in the near future, is there a way to charge that Li-ion battery using the Ni-Mh cells, when it goes low and there's no electricity? Please advise if something like this exists or if someone already made it. Regards, RS 

Topic by rseni   |  last reply


What is the optimum charging voltage for 1.2 volt ni-cad rechargeable AA batteries? Answered

I am going to build a solar panel that charges these batteries so i I need to know the best voltage to charge them.

Question by airsofter1   |  last reply



Zapped a battery.?

And still wont charge, it's a 36v Ni-Cd. it has 10 separate cell inside the plastic holder, which i took apart and zapped individually then soldered back together. i did not try to charge it for 1 week after zapping, should i have charged it immediately. Or any other ideas

Question by johnnywgk   |  last reply


charge battery

I have battery 1cell NI-MH AA 1.2 v 1500mAH   and i need to charge it by using smps and diode for detect peak voltage of battery   i prefer fast charge for maximum 2 hours for my project  how much voltage and current i need in output of smps ?

Question by omar kotrash    |  last reply


Help in buying Solar Charge Controller?

I want to buy this. What is the best battery and solar panel for the same. I want  to use 6V rechargeable lithium batteries. I am guessing 2 in series will be required. Can I use array of Ni-MH pencil batteries with solar chargers? I will be mostly using the setup for emergency power supply in all rooms (5). I may also use night lamps as trickle drain.

Question by artworker   |  last reply


Low voltage cutout

Hello, I need a simple circuit to switch off a high brightness LED that draws 200ma when my four cell Ni-MH battery pack drops to 4.0v(1.0v per cell) Nothing too complicated, something with a transistor, a comparator circuit, and a zener or an all in one IC? I've tried a few "this should work" circuits and then have been told, "well I haven't actually built one". Thanks.

Topic by jefflahay   |  last reply


How many volts and amps would i need to charge 10x 1.2v 1800mAh Ni-MH batteries at the same time?

So i have a battery pack of 10 rechargeable batteries (1.2v 1800mAh) and i was wondering how many amps and volts I need to charge them all at the same time. Instead of having to take out like 2 at a time to charge them. Is it possible to charge them all at the same time? Thanks for any answers!

Question by Alberto64   |  last reply


Where do I find "non standard" Seebeck coefficients? Answered

Specifically: I am interested in making a small thermopile for some experiments, for operation at pretty high temperatures. I have plenty of ni-chrome and constantan wire, I also have 304 and 316 stainless steel welding rod. Apart from by experiment, how can I find the output voltages/ deg C of any combination of these metals ? I can't seem to readily find the Seebeck coefficients for stainless steels. Thanks Steve

Question by steveastrouk   |  last reply


LED that light up if the battery is charged

I am making a solar charger for one Ni-Mh battery 3000ma. My solar cell is 2V 300ma. I want there to be an LED that will light up, if the battery is fully charged, I went through alot of articles online, and here is a circuit that I think might work, but I'm not sure, so if you could tell if this is going to work or not, it would be great, and any modifications I can do. I'm not sure about the value of the diode. 

Question by NiKiToS   |  last reply


Need help identifying the components Answered

I am not able to read the information on the item (too small) - it is red (ish) with a black band. See attached picture. This is out of an Energizer dynamo based flashlight ( http://www.energizer.com/_layouts/displaylargeimage.aspx?image=/SiteCollectionImages/products/lighting/preparedness/large/WRCKCCBP.jpg ) with a 3.6V 80mAh Ni-Cad battery with 3 lead input from a dynamo (6 diodes in the picture). If anyone had access to the schematic for this, that would be even better :-) Updating with a better picture... Not much better.... But a bit better. I can not get any closer without it just getting fuzzy...

Question by rcravens   |  last reply


solar circuit not working properly? any ideas?

I am building a solar powered charger for when I go on holiday, I know there are already some instructables on this but and can't seem to find anything to do with my problem. I use the solar panels to charge Ni-MH batteries  and when I test them in a simple circuit i.e. solar panels connected straight to the batteries, they charge but in my circuit below the battery connections on the casing heat up and the casing smokes. Obviously this is a problem but I don't know what is causing it. My schematic is below. Stu

Question by stuart576   |  last reply


How to recharge these batteries?

I took apart 2 cordless drill batteries and there were 13 cells in each one, which were Ni-Cd 1.2 volts each. Also there were the numbers C DE35ND on them if that helps at all. I cut 3 off in order to form a 12v battery (it was originally 15.6v) but I dont know how I can safely charge it. I no longer have the charger that went with the drill, but I was wondering if I can just use a wall adaptor to charge them or do I need a better charger? All comments and answers are greatly appreciated!!!

Question by Electronics Man   |  last reply


Where can I but a JD1803 chip?

I recently went to my favorite store,The Dollar Tree-everything for a dollar, and found some small solar lights.  When I opened it up I found one bright white LED, a solar cell (about 2,5V) , a AAA NI-Cad battery and a Joule Thief on a chip. I have been building these as artsy  gifts for people so reducing the circuit board down to about 1/4"x1/4" seems great. The chip is four in line pins,  However upon looking I can't seem to find them. I did find that they were, of course, made for a Chinese manufacturer. Can anyone help??

Question by wilb   |  last reply


Any help or suggestion? Answered

For some time I have problems accessing Youtube, either directly or from a instructable. Until yesterday, the problem was that the videos interrupted partially, and I thinking that Speedbit VideoAccelerator had something to do, I uninstalled it. Now I can not access at all, I get the following error message:      The connection has been reset           The connection to the server was reset while the page was loading.      The site could be temporarily unavailable or too busy. Please try again in a few moments.      If you are unable to load any pages, check the connection your computer network.      If your computer or network is protected by a firewall or proxy, make sure that Firefox is permitted to access the web. I have no problem with Vimeo. -------------------------------------------- Desde hace un tiempo tengo problemas para acceder a Youtube, ni directamente ni desde un instructable. Hasta ayer, el problema consistía en que los videos se entrecortaban, y pensando que el Speedbit VideoAccelerator tendría algo que ver, LO DESINSTALÉ. Ahora directamente NO PUEDO ACCEDER, me sale el siguiente mensaje de error:      La conexión ha sido reiniciada      La conexión al servidor fue reiniciada mientras la página se cargaba.      El sitio podría estar no disponible temporalmente o demasiado ocupado.      Vuelva a intentarlo en unos momentos.      Si no puede cargar ninguna página, compruebe la conexión de red de su equipo.      Si su equipo o red están protegidos por un cortafuegos o proxy, asegúrese de que Firefox tiene permiso para acceder a la web. Con Vimeo no tengo problemas.

Question by rimar2000   |  last reply


Help with chardging batterys in paralell?

I have a Nikko Super Dictator witch I replaced all the eletronics in it apart of the engines. I used an rc reciver I found lying around out of a plane. I put this in the car (it olny has one engine now because one was blowen with the eletronics when I got it). The problem is that the batterys get hot and run out very fast. Each battery is 9.6 volt, 650MAh, Ni-MH, and the chardger is 9.6V, 300Ma (the batterys are equivlent to 8xaaa batterys in series). I want to wire two batterys in paralell and tape them together. How, and what, would I chardge these batterys I have made?

Question by David97   |  last reply


Control your pc with Kinect sensor?

I am running windows 7 64bit, after getting the xbox kinect for my 360, I thought it would be a good idea to control my laptop with it, I have installed the necessary drivers to use the motor, audio and camera although the programs for keyboard mapping won't connect to the camera. I have FAAST, Open NI prime sense and yet none of these will pick up the sensor. here are some websites I have looked at: http://people.ict.usc.edu/~suma/faast/ http://www.wolfgangherfurtner.com/ http://openkinect.org/wiki/Main_Page I have followed all the steps on the open kinect website yet it is still not working. Any help would be appreciated, thanks in advance.

Question by freerunnin1   |  last reply


Why the cordless drill motor not run?

Hi all, I have a problem with the motor of the cordless drill. I converted my cordless drill from Ni-Cd battery to Li-ion battery 12v6 using the protected PCB as this image: http://www.ultest.com/shop/image/cache/catalog/Power-Modules/HX-3S-A01-1-500x500.jpg. After connecting the 3 cells Li-ion battery to PCB, I measured the voltage at P+ and P- is 12v. So the connection between the battery and PCB is correct! Try to connect P+ and P- (from PCB) to the positive and negative terminals of the motor, then the PCB cut-off voltage at the output pin. The reason is the 2 terminals of the motor is connected (using the Digital Multimeter to check). How to resolve this problem with the motor working properly? Thanks. Sy Do

Question by sydo   |  last reply


Is it possible to recharge old, long-dead, camcorder batteries? Answered

I am wondering of there is a method for revitalizing old camcorder batteries which refuse to charge. I know that certain camcorder battery chargers used to come with a "refresh" button. However, the chargers that came with my batteries lack this feature. I believe that most of the batteries are Ni-Cd's. However, one of them is lead-acid. The lead-acid battery is from a VERY old camera, one in which you placed the camera on your shoulder, and slung a VHS VCR from the other. When you were done recording, you would then take the VCR and plug it into the a matching TV tuner. This would charge the battery. Any ideas that would help me get some charge into these batteries would be appreciated. Thanks!

Question by Infinitevortex   |  last reply


Charging NiMh batteries using a small motor - Help!!

I want to build a battery charger that is capable of charging 12v (2x6v) of NI-Mh PCB type batteries (varta packs from farnell) . I think the batteries are button types bound together. The input will be from a small 1" diameter motor spun to give 12v out (I assume this is a dynamo). The output from the batteries needs to power : a 12v wireless reciever (6mA standby/66mA switching) a 12v - 24v dc/dc converter powering a solenoid at 25mA@24v. I have seen a 12v charge regulator in Maplins but it is designed for car batteries. If I send the 12v motor/dynamo output to the charge controller and then onto the batteries will they blow up? As I am a mechanical engineer this is new to me so can anyone help ?

Topic by bluegitty   |  last reply


Efficient LED lighting? Answered

I want to power 3x 0.5W LEDs in series with 3x AA Ni-Mh batteries (input voltage will range from 2.5 to- 3.7 ). The total forward voltage is around 10volts, and the current of the LEDs is 150mA. I've tried using a Joule thief but it's quite inefficient, even with different transistor / toroid / resistor configurations (even with fast switching Darlington transistors) the maximum current I've been able to get at the LEDs is less than 100mA, and many energy gets lost in the process, it seems the resistor between the coil and the base of the transistor slows down the switching process and limits the current. I need a more efficient way to power the LED's, either an improved design or a LED driver chip. But trying to keep the efficiency rate around 60-70% or more. I have found a design that claims to be more efficient (see picture), but I'm not sure about if it will deliver 150mA.

Question by Victor805   |  last reply


How can I make a compact 800 volt power supply?

I'm making (drum-roll please) a disposable camera coil gun. so far, we've gotten to the point where we have a fast enough output and enough kinetic joules to kill small game. the thing is, we should really make a more reliable power supply than the daisy-chained flash circuits we have right now. any ideas on a more compact supply that I could run off Ni-mh AA's or 9v's? is there a specific way to cannibalize a flash circuit to make it more compact? I'm good with heat-sinks. one idea i came across was to make a resonant transformer but i'm not sure how practical that is. Any ideas at all are welcome. this is the last step before we add another stage.  >G

Question by ltnemo2000   |  last reply


How do I make a truly versatile solar powered cell phone charger? Answered

I have many questions! I am trying to make a solar powered cell phone charger that has lots of versatility. When no phone is connected, it needs to charge 4, 2500 maH Ni-MH batteries. When a phone is present, it needs to charge from either the batteries or a 12 V, 1.5 W solar panel. I have found several voltage regulator circuits, but I don't understand how to calculate the proper capacitor values to stabalize the current using a PT5101 voltage regulator, or how to get 5V constantly if the voltage ranges from 2.4 V, from the AA's in series, or as high as my 12 V from my solar panel? I don't want to buy a circuit, or salvage one, but create it from individual components. Any help?.

Question by Phaedrush   |  last reply


Printing a Random Pattern on the desk

A couple of weeks ago, I bought an Ativa (Office Depot store brand) wireless mouse on sale for $15. It appears that they were clearing out stock, because they no longer list it on their website, but this is the closest thing I've found. I like the mouse, particularly because there is a built-in charger in the wireless tranciever for the two Ni-MH AAAs it takes. Yes, AAAs, the link is for a different mouse.Problem: Lousy resolution, I think. the wired Lenovomouse that came with my computer worked just fine on my smooth, blank desk surface, but this one requires much more of a pattern. I don't like mousepads. Scribbles with a pencil work well so far, but they smudge after a day or so. I want to put some sort of pattern on my desk for it to read. My best idea was a laser-cut random bitmap stencil and a can of black spray paint, but I don't have a laser cutter. Ideas?

Topic by CameronSS   |  last reply


Finished building Low Level Laser Therapy Helmet using #38 3v and #69 5v diodes. The helmet will be used for hair loss prevention. Due to zero knowledge of circuitry, what's the safest and right way to power device? Answered

There are similar projects on this website but all using less diodes. I'm also not convinced that wiring all the diodes in a parallel circuit is the best route. If it is, then great and that will make my life easier.As you can see in the photos, I've soldered the diodes into bundles. However, each bundle either consists of only 5v or 3v diodes. If I need to desolder anything, so be it. Right now there are bundles of the following:5v = 20, 15, 22, 123v = 9, 9, 9, 11The diodes were purchased from Amazon and displayed the following specs:3V Output Power: 5mW Wavelength: 650nm Working Voltage: 3V Operating Current: less than 20 mA Laser Shape: DotWorking temperature: -10 degree~£«40 degree housing: CopperDimensions: 6.5 X 18 mm5V Output Power: 5mW Wavelength: 650nm Working Voltage: 5V Operating Current: less than 20 mA Laser Shape: DotWorking temperature: -10°C to +40°C Housing material: High quality Copper Dimensions: 6.5 x 18mmWire connection: Red wire connect to Positive, Blue wire connect to NegativeOther purchased materials2 x 4.8V 700 mAh Rechargeable Ni-Cd Battery Item Name: Ni-Cd Battery Dimension: 2.16 x 1.97 x 0.59 inches Plug: SM 2P Plug Charging time: About 2-3 hours Working time:About 20-30 mins5 x 4 Cell 4.8V AA Battery Holder W/ JR Style Connector ReceiverUltimate Goal: Simplify powering of helmet for 20-30 minutes / 3x a week by using on/off switch or plug.*This is my first time on this website and I apologize if I entered into the wrong category. THANK YOU in advance to anyone who helps. Greatly appreciated!!

Question by Randyroo1   |  last reply


Solar 3w led fibre optic outside tree decoration

So I have salvaged a solar panel and the battery that it charged from a wireless alarm. The battery is 6v 1.2amps. My plan is to have the panel charge the cell during the day (its Ni-Mh) and using an LDR light a 3w led when its dark. The led will be connected to a number of strands of 1.5mm fibre optic cord, with a number of these attached to a tree to make it look.....nice. I have tested three strands of fibre optic cord with lengths of 2m with a lesser led and all appeared fine. I have a 3.7v 700ma driver (coming from China) which will drive one 3w led, along with heat sink. Now is where I am struggling a little, I am not massively experienced in electronics. I think I want a diode attached to the solar panel to avoid battery drain. Then a resistor to reduce my 6v to 3.7-4v and the LDR. Does this look like it would work in principle? Would the battery run 2 of these drivers/leds or would it discharge too rapidly? Thanks for any input!

Topic by earton   |  last reply


How are spherical rare-earth magnets manufactured? Answered

A question came up the other day when playing with Buckyballs of how you manufacture spherical rare-earth magnets. I'm surprised they could use that name, given the original Buckyball, but these Buckyballs are powerfully magnetic spheres with one side a North pole and the other a South pole which can be stuck together to make 2D and 3D structures.  Sale has been restricted in many places because of people ingesting them and requiring emergency surgery. I've found information on neodymium magnet production using a sintering process, but can't see how you could produce a perfect Ni/Cu plated sphere with this method as individually machining to a sphere would be excessively laborious and tumbling would be a non-starter because of the attraction between balls.  EDIT: The sintering page wasn't the one I thought I was linking, but the one I've linked looks like it may have the answer in die-pressing or isostatic pressing in the aligning field of a solenoid.  Is this how it's done for spherical magnets? (Polishing the coated spheres would still be a problem.)

Question by AndyGadget   |  last reply


How to build battery pack 9.6v from 18650 batteries?

I would like to create a good battery pack for my dead hilti drill. Originel nc-cd 9.6v battery. I have some panasonic cgr18650cg batterys here.  But when 3 in series, the voltage is higher. Maybe the drill can work with a higher voltage but I dont know. Will it work, would like to create first a 3S pack and maybe later a 3S2P  I need a PCB and thinking something like this one : http://www.ebay.nl/itm/12-6V-8A-w-Balance-Li-ion-Lithium-18650-Battery-BMS-PCB-Charger-Protection-Board-/321853922824?hash=item4aeffd1e08 Or this one? http://www.ebay.nl/itm/3-Cells-Li-ion-Battery-18650-14450-Input-Ouput-Protection-Board-PCB-12-6V-8A-/321804037521?hash=item4aed03ed91 And how to charge a pack, can I use a common 12v laptop adapter or other adapters or specia li-ion charger? I dont think the original ni-cd charger can be used with pcb's above?

Question by rnijland   |  last reply


Less then 2 yr old flat screen - has died....I believe...

My 17" Gateway flatscreen went blank this morning while I was at meeting. My wife claims she didn't do anything.....that it was blank when she saw it. It was not in sleep mode, nor was a screen saver on. I noticed the "power button" which is normally green (power up, with computer signal) or amber (powered up w/out signal), would not come on. I attempted to see if any of the adjustments on the side might have been bumped, no effect. I tested to make sure there was power from the surge protector (switched power outlets after a shut down) to no avail. After my 4th reboot, I subbed in my old monster sized 17" CRT tube monitor, and it works fine. Resolution is different, but it works.....but that pushed the monitor about 2 feet closer to my nose then I would like (it is about 10 inches from my face. )Did I miss anything as far as testing the monitor before replacing it? I personally think the PSU in the monitor went on the fritz, but I am open to suggestions. EDIT: The old CRT is now back ni it's storage area, and the newest LCD screen is up and running.

Topic by Goodhart   |  last reply


What is the right way to connect the cells of this battery pack, and tips on making a power bank? Answered

Greeting makers, I have a few questions about connecting Battery cells, and making a DIY Power Bank. And I'd like to hear your opinion on it. I have 12x Ni-Mh 1.2v 3000mAh AA betteries laying around. They are brand new and I thought of using them to make a Power Bank. Since most phones use 5v for charging I wanted to connect 4 cells in series giving me 5v and 3 of these packs in parallel for an end result of a single 5v 9000mAh Battery Pack. But when I started to connect them I realized that there are 2 ways it can be done, and I am not sure which is the right one. Is there any difference at all?  I will add a picture below, as it says more than thousand words. Furthermore I would like to ask for your opinion on how to proceed making a functional power bank. Just wiring the cells straight to an Usb port doesn't seem like a smart idea.  What would I need to make sure it is safe for the devices it charges? And how could I make the Power Bank rechargeable via Usb? Thanks in advance.

Question by icemaciop   |  last reply


PLEASE HELP! how do I fix this laptop? Answered

So quite recently, my laptop quit working, with no warnings or anything, it just turns on, but the screen and hard drive do nothing. it wasn't the cpu so i have ni idea what is wrong with it. it was a acer aspire 5672, if someone knows how to help me figure out whats wrong, please pm me. but this question is regarding another laptop. I got a really cheap acer travelmate 5530 because it had a broken screen and didnt turn on. I have a replacement screen, but the power problem is not as simple as i thought it would be. so now i am asking for help. I opened up the laptop and right in the area where the charging plug plugs into the motherboard there was a blown transistor, marked "E72" just like the second one in the area. I took a picture, but it is kind of hard to tell the bits and pieces because they are really small so its hard to get a picture of them. I did my best to unsolder the tiny transistor but i need to know if any transistor will work to replace it (eg: one from another laptop), or if I am going to have to find another "E72" one. also it looks like some other components are fried, if you guys can help me figure out what they are and what to replace them with that would be great. Thanks in advance,         zack247.

Question by zack247   |  last reply


I need a circuit to run a tiny motor from a USB port? Answered

I made a leather "Steam Punk" case for a portable hard drive. It has several gears that show under a glass porthole and I need a way to move the gears powered from a second USB cable. I'll use a separate USB cable then the Hard drive as I don't want to compromise the original device. I have a very small motor from some Radio Shack ZipZap RC cars. Tried to design a simple circuit myself but can't get the motor to spin. I suspect it doesn't have enough current. The motor does spin if hooked directly to a AA batery. The ZipZaps work with 2 AAA bateries in the charger/controller. The car hooks on top of the controller charges up and then can run for a short time. Opening the car up it has a 1.2 V 100mAh NI-MH battery inside it. Tried looking at a couple of BEAM robot solar engine designs used to run small motors from solar cells but just coudn't figure out how to convert them. I'm looking for a small circuit (in size) that could drive this motor, with a backwards current spike protector so the USB or computer doesn't get fried. I have limited EE experience but can through hole solder but not surface mount. -Steve

Question by nevets_mcd   |  last reply