Search for 5 V in Topics

I am building an arduino by myself using the schematic as the board isnt available in our country. The problem is that i dont understand one thing in the schematic. Its an arrow pointing upwards with 5v written next to it. I am a beginner.Your help will be greatly appreciated :D http://arduino.cc/en/uploads/Main/ArduinoSeverinoSchematic.png

Hi, Anyone know if I can amplify 1.5v DC to 5+v DC (pretty much any value over 5 works) using the LM358 IC (https://www.sparkfun.com/products/9456)? The datasheet (http://www.sparkfun.com/datasheets/Components/General/LM358.pdf) specifies the power supply range as 3V to 32V however the input voltage range is -0.3V to 32V (top of datasheet page 2). I've done some googling but I'm still not sure about the difference between these two.  Any tips or links on wiring this guy up would be awesome, Thanks!

So I am making an electronic t-shirt with a very bright screen that gobbles up amps. At it's probable peak usage it will be using 9 amps (or 8.697, but I always feel safer sizable margin of error). Luckily this will only be at its peak for a few seconds (at most 10 seconds, probably less) when it starts up. Next it will use  between 4.5 to 3 amps continuously, and later will  be using closer to 1 amp. All of this is at 5 volts, and I will be stepping down from 7.4 volts. As if this wasn't hard enough this is battery powered, so good efficiency would be nice. I want to minimize the amount of power lost. Is there a power supply that can do all this and still be wearable? In short, I need a wearable 5 volt power supply that can provide a few seconds of 9 amps and 4.5 amps continuously.  Thanks! Edit: Thanks Everybody! For people who find this in the future, here’s from saving you from having to read through all the posts… In the end I found the answer to my problems was cutting the peak amps it needed to consume it half, bringing it down to around 5 amps. What I ended up choosing was the R-745.0P power supply. Look at the last page of the datasheet for clarification on how to wire it, and when it comes. The mpilchfamily thread talks about safety, which is important and worth reading if you want to know about it. I wasn't sure on whether or not I should go with the R-745.0P and all the supporting components or the UBEC 2-5S, which is an all in one package. I chose the R-745.0P but it’s up to you!

What do you like more, or what did you like more as a kidLego or KnexPersonally i like lego as i think it looks more realistic and i played for days on end when i was younger, also knex is mainly used for guns and occasionally big buildings, but with lego you can make entire worlds!!So far its 5 lego / 3 knex

We're so excited to announce that the Epilog Challenge is back for its fifth year! We've teamed up with Epilog to give you the opportunity to win a fantastic Zing 16 Laser, power tools, and Instructables prize packs. Epilog Challenge V is open April 15th through July 15th - so you've got a long time to build something awesome. We can't wait to see what you make! Head to the Epilog Challenge V contest page to get all the details.

I'm considering running a 3v fan from a 5v usb. can i simply put adequate resistance in series to reduce current to acceptable levels?

Can I charge my psp with 6 volts (aka 4xaa) ? even though its only supposed to have 5v....Or do I have to go to the source ( what used to be radio shack in Canada ) and find a regulator. If so what little digits should be on it ? and would any of the following regulators work ? AN6541 IRL3103 ( I already have them I ripped them of of old mobos) To explain I lost my wall charger and usb charge don't work unless its on..... and the battery is dead

Hi, I would like to make a lightbox and charge it from a Solar cell . I saw a 5v ledstrip online , but I am wondering wich battery and wich Solar cell I have to buy? I mean how much voltage en watt does this ledstrip need? Wich diode do I need?  Another question: I want the Solar cell to charge during the day and I need it's power during the night , do I have to do something special with it ? I mean in the most cases you will have the energie richt away, that is not my plan .... I rather not use an on and of switch , I want to use it automaticaly.    I  just started with the diy adventure? Forgive me :)  greetings deborah

Hello all well,I live in Brazil, I am an artisan! I have questions about making one (Homemade 5 axis CNC) for sculpting Styrofoam or clay.An example :https://www.youtube.com/watch?v=nITLI_WcnuM&feature;=youtu.beAnother example :https://www.youtube.com/watch?v=PhexbkJpvWA&feature;=youtu.beI need 5 axis CNC. I searched the internet and found no example, no tutorial. Can anyone help me?

How to convert 12volts 7 ah to 5 v 1ah 12 volts can be connected to 7805 for converting into 5 volts but how to convert current. current could be limited through resistor but which? also give formula of how to found it out

Hi! A while ago, i made an A/V selector, and it worked quite well. It had a small design issue, which is, having the ports at the front, where the switches are, and I want to upgrade it a little bit. The idea is, put on the front the switches with a LED on each input, and when I switch the selected input, the selected LED will also light. I've been looking around, and the A/V voltages are around 1 volt. The switch I have, it can handle 3 circuits at the same time (Video, Left and Right) but it has 3 rows as a conmutator or something. The thing is, i need your help in order to connect the LED. I've been thinking about using the unused row of the switch, but I don't know how, or, place a transistor when the Video input comes across the switch, but I don't know what kind of transistor will do. Thanks in advance I attach a diagram of what is now, with 5 inputs, showing only 2 of them, to have a brief idea

I have these lying around and I know they are useful, but I'm just not sure how.

Hi guys, I want to make a simple battery life indicator for a device running from a 1.5V battery source. I would just need a red/green LED to light when the Voltage is above a certain limit (say 1.2 V). and to turn off once the limit is reached.. Is there any simple circuit that enables me to do this?

The KWR1 (K’NEX War Ready gun #1 Version #1) V.1 came out of my idea to build an entirely “mod-able” slingshot sniper weapon that you could rely upon in any outdoor K’NEX war (hence the name). You could make this gun longer; you could make this gun shorter. You could add a nonadjustable stock; you could make the stock longer, you can do practically anything to this gun (other than change the mechanism and the handle position).   Features: Good range: 60 ft. (1 band) – 100 ft. (5 bands, 45 degree angle) Can shoot: Oodammo (1 band: 60 ft.), Large K’NEX wheel (5 bands: 30 ft.), Small K’NEX wheel (5 bands: over 80 ft.), Lego bricks (5 bands: 50 ft.), NERF darts (5 bands: 50 ft.), and size #117 bands as a RBG (30 – 40 ft.) 10 point adjustable stock (see pictures 8 -11) with “Stock lock” (see pictures 13 - 15, 17) Totally customizable Safety (see pictures 15 - 16) Cheek rest (see picture 9) Not too piece consuming   Now, with all of that out of the way, I want to talk about ammo sizes and the “the more bands, the better” myth. So to do that, let’s look at the stats (shooting with three size #117 bands):   Red Connecter Ammunition: No rod attached: 62 ft. Green rod attached: 55 ft. 4 in. White rod attached (oodammo): 42 ft. Blue rod attached: 35 ft. 5 in. Yellow rod attached: 40 - 45 ft. Red rod attached: (got caught in the bands) Grey rod attached: (got caught in the bands)   Grey Connecter Ammunition: No rod attached: 64 ft. 9 in. Green rod attached: 59ft. 4 in. White rod attached: 50 ft. Blue rod attached: (got caught in bands) Yellow rod attached: 40 ft. Red rod attached: (got caught in bands) Grey rod attached: (got caught in bands) As you can see, the larger the round got, the lower the range you would receive. I think that this is a direct proof that bigger bullets are not necessarily good ammunition. For example, the ZKAR uses yellow rods? Might it get better range if it shot blue rods? Now, admittedly, the instances may be different with different guns, but I highly doubt it.   Conclusion: Stick with ammo sizes between blue rods and white rods (including both the blue rod and the white rod).     Now I want to talk a little about the “the more bands, the better” myth.   I took the KWR1 out to my backyard, grabbed some oodammo (growing in our garden, mind you), and commenced shooting from a prone position. Then I got this idea… what if I was to shoot with only 1 band, and not all 5? So I started to do that, leaving the bullets where the fell after having been shot. Then I decided to go back to shooting with 5 bands, to see how much better the range would be. So I fired a couple rounds… and got no better range than I did when I shot with only 1 band. I did this a couple more times, and found it to be true.   There is a myth (myth = a traditional story) pervading instructables that you will always get better range with more bands. Now, it is my personal opinion that if a gun can’t get 50 ft. with two bands, it’s no good, but that is irrelevant.   Conclusion: More bands does not necessarily mean better range.     Now, I am not stating these subjects as fact, for that would seem arrogant and presumptuous, but I do believe they are, to some extent, true.   -The Red Book of Westmarch

Hey guys, I am about to set out and create Ben Heck's A/V selector.  http://www.engadget.com/2007/03/13/how-to-make-a-solid-state-a-v-switcher/ He uses a bus switch, CBT3244A, Digi-Key part # 568-3619-5-ND (out of stock I believe).  While I could order a comparable bus switch, I have several lying around from hacking apart a kid's toy.  74hc374. I've looked at the datasheets and, I've never been very adept at understanding them, preferring the lazymans terms.  I understand that the original chip has 2 switches (to use for two separate a/v connections, or turning both on for a connection with more pins) while the chip I have has only one switch, allowing up to 8 channels to go through. What I'm confused about is the state of the "on" switch for the one I have, or maybe the clock.  From what I understand, they each need to be pulled LOW (connected to ground) in order for their respective inputs to flow through, can the clock, in my case, be ignored? For the arduino tags, I do plan to make this project remote controlled.  But I'm a serious beginner in this area.  Basically I plan to replicate this project for arduino.  http://www.tauntek.com/tinyir2-learning-ir-remote-control-receiver.htm  Would there be a point to that?  Or would it be simpler to just order the chip by itself already programmed.  I think that programmed tinyir2 PIC chip and arduino chips come out around the same price wise.  I have the other components lying around already.

I'm using a collection of broken laptop and desktop monitors I got free from a repair workshop to assemble a floodlight/spotlight from the CCFLs and their inverters. The desktop monitor power supplies take mains voltage (240 V) and power the CCFLs but also seem to provide a 5 V and 12 V supply to the electronics that control the LCD. The laptop inverters themselves accept either 5 V in some cases or 12 V in others so naturally I want to run the laptop inverters off the 12 V and 5 V supply because otherwise it's wasted. The problem is that I don't know how much power I can draw from the 5 V and 12 V of the power supply. I've had a look at the back of a monitor that says it draws 0.7 A at 240 V. What translates to 168 W which is more than I was expecting. Assuming that the four built-in CCFLs use 8 W each, that would still leave 136 W. Assuming the power supply is only 60% efficient that leaves (168 W x 60%) - (4 x 8 W) = ~68 W. I've no way to tell how that's distributed across the 12 V and 5 V but if it's 34 W each then I can draw 2.8 A from 12 V and 6.8 A from 5 V? I figure I can probably, maybe attach eight laptop inverters to each desktop PSU (four on 12 V (1.6 A) and four on 5 V (4 A)?

Tbd392nr lcd inverter

I'm buying a sega game gear to mod. I want to add an a/v input without using the tv tuner accessory. Is this possible? I cant find it anywhere online, but i did find a pinout and it seems possible. I know i could connect the audio to pins 44 and 45. Would it work if i connected the video in to pin 43? Any help would be appreciated. Thanks in advance. 1 +34(V) liquid drive                                        24 MREQ memory request 2 +5(V) +5(V)                                                    25 A10/TPR2 address 3 /WR write signal                                           26 /RD read signal 4 A12 address                                                 27 /EXM 2 0~7FFFH 5 A7/CL1B3 address                                      28 A15 address 6 A6/CL1A2 address                                      29 A11 address 7 A5/CL1B2 address                                      30 A9/TPR1 address 8 A4/CL1A1 address                                      31 A8/CLIA3 address 9 A3/CL1B1 address                                      32 A13 address 10 A2/DW address                                          33 A14 address 11 A1/DO3 address                                        34 /EXM1 8000~BFFFH 12 A0/DO1 address                                        35 +5v +5 volts 13 D0/DB data                                                 36 /M1 M1 cycle 14 D1/P3 data                                                  37 IORQ I/O request 15 D2/P2 data                                                  38 /RFSH refresh 16 GND D ground                                           39 /RESET Reset 17 GND A ground                                            40 CCLK Clock 18 GND D ground                                           41 GND Ground 19 D3/P4 data                                                  42 /GG MS/GG 20 D4/P1 data                                                  43 /TV TV Cart 21 D5/CL2 data                                               44 TVSNDR VR Right Audio 22 D6/DO2 data                                              45 TVSNDL TV Left Audio 23 D7/DO4 data

Dear all,  i am bit confused and want your expert help for following matter. 1. I have 12v 6A (2A X3 each= 6A)  RGB contoller  : as this link http://www.ebay.in/itm/24-key-IR-Infrared-Controller-remote-12V-power-Adaptor-fr-RGB-Strip-flood-Light-/161201011884?pt=LH_DefaultDomain_203&hash;=item2588543cac  2. I have 5 mm common anode led: as this link  http://www.ebay.in/itm/RGB-LED-5MM-Common-Anode-20pc-Set-/151542871353?pt=LH_DefaultDomain_203&hash;=item2348a8b539 i want to connect this 5mm common led total 6 nos with above mentioned 12v 6A RGB contoller.   how to connect it safely so that led will not burn . because red needs 2.2 v  , 20 ma , blue and green need 3.2v  , 20ma  to light up. and source is suppling 12v 2A . i think if i connect it directly . it will burn the led. 

The circuit diagram is shown below and the source of where I found it. http://www.youtube.com/watch?v=Yd3hzYAJzOoOnly problem is, I have no idea what values I should use, what vdd, vcc, q1, q2, q3, u1, u2, u3 and where power comes in.Could somebody tell me vdd and what vcc is?And perhaps what this guy is using as u1-3 and q1-3?Plus where the power comes in.And possibly what resistor values i should use that correspond with: (5-12 volts your choice) and 3 regular 5mm leds @ 3.3 volts 20ma?To go above and beyond... you could make an instructable elaborating this guy's design. :D

12 v input3.3 v and 5 v output

(Gosh, it's been a while since I posted a forum!) So 22222222539 is leaving, and I don't want another contest to just die like the rest, so I contacted and got permission to continue the contest as the new host. here is the original forum topic: ROUND 2 A Knex ball Machine lift Duration This round will last from November 30th to December 8th Requirements Must be able to lift a standard knex ball or ball of similar size. Must lift the ball up at least a foot Must be able to AUTOMATICALLY pick up the ball from a short entry ramp Specifications You may use      knex      tape      string      A motor other than knex You may NOT use      modified pieces      wood / other plastic / metal / etc.      Points system up to 10 points-each judge gives up to 5 points for overall up to 8 points-each judge gives 0-4 points of innovation up to 6 points-each judge will give up to 3 points for looks up to 4 points-each judge gives up to 2 points for the speed of the lift up to 10 points-I will give each creation up to 10 points on how much I like it Bonus Points 2 points-a video displaying the qualities will add 2 points 2 points-if you do a complete instructable on how to build it. 5 points-If you complete a ball machine you will receive up to 5 points from me Contestants and Entries Knex mad Killer~SafeCracker trauts Wicky knexsuperbulderfreak Kinetic Big Z chopstx Coreyt Smilee bigdylan91 logic boy How the scoring works The amount of points you earned from last round will be added on to the total from this round to get your total to see who advances to the final rounds. The highest total will receive a bonus on the final round. DEADLINE DECEMBER 8TH I know the deadline is rushed, and I am willing to extend it if needed, but try to make it on time. Im rushing this to try to get the next round in during Christmas break so you have lots of time to work on your creation. Backup project: If for some reason you can't make a ball machine lift, you need to make something that will do a basic task, probably powered by a crank or rubberbands. Ideas: A hand powered by cranks to move it on a X, Y, Z axis A Rubberband powered can opener ect. Be creative with this Project. I want to see really amazing things. Please note you can only attempted the Backup project if you have a valid reason why you can't make a ball lift. Everyone who has the pieces to build a ball lift has to. if you have a valid reason, please post it as a comment to this before making your project so i know. When your done, post a like to the foruminstructable for me to put up here. Now get building!  

I created a slide show of 5 or 6 pics and I cant view it .it was for the halloween costume contest and it is no viewable .

Hi, i'm trying to make, laptop cooling pad as own. hope it will help many members here, my concept  - i want to connect 2/3 DC fans(axial box fans, generally finds in computer cabinet) & through USB connector, i want to join it to laptop.for a cooling purpose. but, now i am simply using 1 fan to 5 v usb right now.(i had tried 2 fans at one connection but another fan goes slow, so not confident about this experiment) can you guys help me fast. Some Points to Consider - fans which are going to connect 5 v USB connection should not Exceed 500mA. (heard that USB should not drawn more power than it. & should not be hectic to laptop battery but still very effect). please explain here in detail.

Does anyone know how I could use the RF MODEM which I removed from an old VCR to convert S-Video out (PC) to RF in on an old black and white 5" portable TV?I'd like to use a 5" tube as a small monitor which will hook-up to my PC without lacing it through VCRs cables adapters etc. And if I find my A4 Fresnel lens I want that worked-in too.The pins on the MODEM are labeled (left to right) as follows:(1-7) BB+ AUD SDA MB+ SCL VID VT+(8-13) (none) (none) AS SCL SDA B+ (14-16) TU (none) (none) (17-20) A/O S/O AFT V/ORF in at the top, RF out at the bottom(I also have a large colour TV with UHF SCART & composite inputs, but I think there's a fault with the HT supply to the tube. I have a large CRT colour monitor, but I'm not too sure I want to take that apart.)L

I am finishing up my quadcopter build, but forgot to buy an UBEC. My ESCs are OPTO, a fact I unfortunately did not realize until I had bought them. So, I am attempting to design my own circuit to reduce the 11V 3A battery I have down to 5V 1A for my receiver and flight controller board. So my question is this: can I use a simple 5V regulator to reduce the voltage and amperage? Or will 3 amps going into the circuit fry the regulator? I read that putting 2 regulators in parallel will increase current; however, I believe that is only for the output of current from the regulator(s). Any and all help is appreciated!! Thanks in advance!

My removable magazine for dj radios AR-4 Commando V-3 Pros-holds 7 yellow rods compared to the usual 5-ammo doesn't fall out when you have it in your pocket or you for some reason shake it vigorouslyCons-none that I can see comment and say whether I should post

Hello i have a question.. i have made a usb charger  using a 9 v bat and a 5 v voltage regulator  but the battery  duracell  overheats way to much... same batt  connected to a led strip 12 v. it works but it overheats as well..... any ideas? my usb charger is on my page..... anybody have an idea why this happens?   cheers

I connected 2 ethernet cables together by simply removing their shields and twisting the naked wires together. I was able to get a good connection but a very strange thing is happening. I need to connect the green wire just to start the connection. Once the connection is established it does not matter if the green wire is connected or not. After some time the connection turns off and to turn it back on I need to re touch the green wires together. The connection comes off if I turn off or on any switch in my room! What is happening? I have also made a video of the thing if anyone wants to see it, in order to better understand the problem. This is the youtube link (http://www.youtube.com/watch?v=5jBB32xISNM?) Please, if anyone knows what is happening and the reason for this let me know. Also, how can I make this connection more durable? Note: I just added an image to show the distance between the two unconnected green wires. The net connectivity is On even when the green wires are not connected.

I will be preping the hull with wire brush & Needle descaler , cut and grind V for patches.

Hi all, Can someone show me how to make a car dimmer or point me in the right direction to make one. Just to recap this is like the new cars when you open the car the light fades up and when the car door is closed the light will take 5 to 10 seconds to dim out. Thanks in advance.

I am selling my Film Canister LED Flashlight Kit. The Kit Includes: #Film Canister #5 ultra-bright white LEDs #Push switch #3V battery #wire #solder +instructions on building the flash light You will need: #soldering iron #electrical tape #wire cutter Cost: The cost of each kit will be $12, whit out the cost of shipping! When you tell me your location I will calculate the cost of shipping. Payment: I DON'T have PayPal so you just send the money to my address. When I receive the money I will send you the kit! What to include in PM: # Name # Amount of kits you wish to purchase # Email address (legitimate email address please) Once I receive your PM, I will send out the request to your email, and then you can purchase the kit. Once I receive the payment, I will ship the kit. If you have any questions, feel free to send me a private message. Thanks!!!

Have several amps and several speakers... 1 The most modest: a 2.1 computer sound system, probably ca. 5- 10 W RMS, 18 V (I want to connect this to my 18 V portable drill batteries- how much run time ?) 2 The medium size: a 12 V  (2, or one) 16 A fused: 2 average 9 x 6 car speakers 3 The meanest: A big 4 channel amp, bridgable, 12 V, fuse is 36 A, a big sub and 2 average 9 x 6 car speakers Volume is determined by the MP3 player, I hope being able to make it, amp inputs are selected by a passive crossover I like the volume loud, but not extreme (< 100 dB). Runtime 5 - 3 hrs. How big a (car) battery I would need for solution 2 and 3 ?

I need 10 solar cells that each produce .57v and .4 amp to be wired together to produce 5 v and 4 or 5 amp. (Series? Parallel? I just can't understand them very well!)A simple drawing would be the best :)Thank you all soooooooooooooooo muchSolved! Thank you for the help! here is a diagram of my solar charger (from what i learned here)

Hi, I have to DC device  a) works with 5.V    (b) 1.5 Volt...  I am using mobile charger as a power supply.  How can i connect them with one mobile charger....as the charger output is 5.V  only.  a) works fine but as the other device require 1.5 Volts . Which type of power  component should i use to supply additional appox. 1.5 Volts ? will any of these can device blast ? Any type of tips n tricks will be very help full. Thanks, Richi

Please note: I am beginner at this. Ok, here is what I have done: 1. I have upgraded my System Menu to version 4.0 using the update option from the Wii2. Following this instructable: https://www.instructables.com/id/S9RV0FWFN4H8OED/ I have installed cIOS36 Rev7. This means that I have also installed Homebrew Channel (using Bannerbomb exploit ). 3. Following the same instructable I have got to the point where I got the Error ret-2011 which a lot of other people (with System Menu 4.0) got: " tried to install the 04-BackupLauncher0.3g+_249-NeoRame.rar like instructed below.I get a installing ticket...ERROR! (ret = -2011)"4. After that everything went down the drain. I have tried to follow this instructable: https://www.instructables.com/id/SQHX9S3FUNOXOKE/ with both versions (offline and online), but I kept getting the -2011 error. 5. I have tried to follow other tutorials out there but I did not get any further because of different errors. Now I do not know what version of cIOS or other files I have installed on my Wii.I have tried to update again my System Menu 4.0 in case I have messed up anything but my Wii says that I already have the latest version installed. So my questions are: 1. How do I know what version of the Files I have and whether I have messed up my System Menu ? And how do I get back to the original System Menu 4.0 of the files? 2. Since the aim of this entire thing is to play backup games, how do I fix this and how do I get my Wii to play the backup games, from backup DVDs (I've seen that it might be possible to play them from USB devices, I am not interested in that right now). Also, I do not want to install any other homebrew applications (like DVD players or video players).3. If in the process I have to downgrade my System Menu, what are the exact steps to do that? Thank you very much for your help and I hope someone will be able to help me make things work !If you think you can help but you need more information, please comment on my question and I will provide as much information as I can

How can I use a 6 Volt power source to power a 5 Volt USB port and a 1 Volt LED?  I know I need a regulated voltage for USB, but how can I get the remaining power to go to the LED?

I understand the operation for capacitors, which make a lot of intuitive sense to me, and seems deceptively simple. I know that the derivative  of the voltage across a capacitor (the slew rate, if you will) is proportional to the current, for a given capacitance. So when the voltage is not changing much, like when it is connected across power supply rails, and the capacitor has little-to-no current flowing through it, and it appears as a high impedance. Fair enough. And when I am winding up the wick on the constant-voltage power supply, so that the slew rate is constant, and the voltage is changing at a constant rate, the current will be relative to how fast that voltage rising/falling. Again, that makes sense. I have proven that to myself time and time again. The technical math way of showing all that is this:          dV/dT * C = I or with units plugged in: d(volts)/d(seconds) * Farads = Amps (or something like that)   Likewise, I know that I can do things in reverse, and that forcing a controlled current through the capacitor, that the slew rate of the voltage across the capacitor will be proportional to that. In other words; the voltage will be integrated over time (as it steadily rises or falls). I do not like integrals in math (esp. when they require by parts or partial fractions!), but the concepts do come in handy in practical design! This is also my 2nd favorite way of imagining what an integral are! (My favorite is actually the water cup or well analogy, where a water faucet or hose is a function, and a the level of water in the cup, pool, well, etc. is the integrated result. That makes the function of integrals really clear and deceptively easy LOL!) So, I basicly have been trying to figure out how to take these simple, easy-to-understand relationships, and take ohms law, and have a super basic RC circuit, with 5V, 5 ohms, and 0.1F. I have so far figured out how to take ohms law, substitute I in the capacitor formula, and get a function. HOWEVER, this is where I get stuck. -------------------------------------------------------------------------------------------------------- Here is the circuit:            +5V---(V2)-----/\/\/\/\/\/----(V1)-----| |-------0v----(grd) So after having a bit of a think, I have figured out that I really need to account for 2 different V's. The 5V power supply, V2, and the voltage across the capacitor, V2. I know that the current flowing through everything in a series circuit is the same, so then I can easily figure out current by calculating the voltage drop across the resistor which is this:            I = (V2 - V1) / R  So now, lets plug that into the mysterious capacitor derivative thingy: (All I did was substitute the I in the capacitor formula with the that ohms law formula above.)           dV(1)/dT * C = (V(2) - V(1) ) / R. -------------------------------------------------- Now, I just plug in the values, and simplify as much as I can, to make it more friendly to my eyes. C = 0.1F, and R = 5 in my case, since I am using a 5 ohm resistor, 100mF capacitor, and I know V2 = 5V, since that is the output of a 7805 voltage reg.           d(V(1))/dT * 0.1F = (5V - V(1) ) / 5ohms. That dV/dT is a bit hard to look at, so I will use V prime, or V' to represent that instead:          V(1)' * 0.1 = (5 - V(1)) / 5 I do not know how to simplify that further though, to end up with that weird inverse exponential curve that is the time constant thingy, with that decaying charging curve. I have V on one side, and V' on the other side. :( So this is how far I got:        5 + (1/2 * V(1)') = V(1) EDIT: I HAVE ADDED THE PROOF HERE IF YOU WANT IT

 I have a small model battery charger which has a resistor burnt out . output is 7.5  volts  according to the label which sounds right as pack is 7.4volts.  measured voltage from transformer  is 15 volts Can anyone tel me what value resistor I need to drop the  voltage  to 7,5 v or whatever the actual out put shoul be. thanks people, john mantova

It's been years since I had an expensive meter. These days, I have meters in the $5 to $20 range. Usually they're accurate enough for my purposes, but what if I want to be really certain? Is there a way without a pricey meter to test em?  Perhaps calibrate the meter by checking v  coming out of a v regultor. Would that be accurate? Perhaps the 7805 regulator which is supposed to output 5v.  y?n? M?

Requirement: Simple Charge Controller with Low Voltage Protection For 6V Battery: Solar Panel Open Circuit Voltage: 10.1 V (6V, 5W panel) 1. When battery is charging we require a "orange LED" to glow, as an indication of charging. 2. When battery reaches 7.2 V or above, a green LED shall glow indicating full charge. Additionally, the circuit should be capable of disconnecting the panel from battery (Simple PWM based). 3. When the battery reaches 5.2 V, a red LED shall glow indicating low voltage. Along with the red LED indication, we require a sound indication "beep", to alert the user to switch off the lamp. The interval of beep shall be between 5-10 seconds. Additionally, the load should be cut off from the battery, when the battery reaches 5.0 V. The battery low indicator (red LED) should glow only when the load is on. When the load is cutoff, even the red LED and the beep should be off. The load shall be reconnected only when the battery reaches a voltage of 6V. 4. A USB female port with 6V output for mobile charging is also required in the circuit. For 12V Battery: Solar Panel Open Circuit Voltage: 20.1 V (12V, 10W panel) The requirements are similar to 6V battery circuit with the following changes: Battery full indication: 14.8 V Battery Low indication : 11.2 V Load Cutoff Voltage    : 10.8 V Load Reconnect Voltage : 12.0 V USB output is same at 6.0 V using very simplest micro controller like 12F675 or cheapest/easily available on market.?

would it be posible to make this top useing LEDS? i know it was blue screen but i still want to try it, it would be cool if i could get it working heres a link to what i want http://www.youtube.com/watch?v=5-5mGwyhruo

OK guys i need help in a simple project i need to make 15 board every board have 5  white LED its 5mm 3.5 v some boards will be connected i when and got 150 LED and 5 test board  but cuz i don't know what resistors i didn't get any so i made my first board connected a Nokia charger to it , it gives DC 5.7 v and 800mA  it burned all 5 LED i used . i will cut the boards down to 15 or 20 small ones OK i will connect 5 boards to gather. how can i calculate what resistor to use . should i use this charger or i get another one. what should i pay to make that work .:update:. i got 150 resistor 150 ohm 2 220v to 5v 1000 mA adapter  and 5 more test boards the first test i got  from a usb cable the lad give me a blue color that is a sign of great power  the with the resistor it gave me white color so i will make the 2nd test with the adapter

I just bought a new Sansa e260 and I've been looking at these usb chargers but they all use 9v or AA and i have a ton of rechargeable AAA battery's, There 1.2 v so 5 will be 5v. Will this work if i just make a case draw the power from them out via usb?

Hi, I have this led strip  http://www.supernight.cc/supernight-tm-5m-16-4ft-smd5050-rgb-double-row-600-leds-tube-waterproof-led-flexible-strip-light-12v-120led-m-strip.html Working Voltage is 12VDC. Working Current/meter: 0.8-1A the strip is 5 meter. 18650 x4 = 14.4 v 18650 x3 =10.8 v How can I make it work with 18650 li ion batteries? And how many battery must I use and how can I do that? I think that I need driver or booster to get a stabil 12v! work-time I need 5 h

Hello, I built the ark welder from this instructable found athttps://www.instructables.com/id/Build-a-Microwave-Transformer-Homemade-Welder/ I'm trying to figure the new wattage I have two transformers 1: 650 watt MOT-primary at 120 volts 60 Hz 5.41 amps secondary at 16.5 volts 39.36amps 2: 600 watt MOT primary @ 120v  60Hz  5 amps secondary @ 16.5 volts 36 amps the primaries are wired in parallel in the secondaries are in series. The secondaries test at 33 V and I'm guessing roughly 76 amps. I want to calculate the wattage. Is the wattage calculator from the voltage on the primaries (120+120)*76 or calculated from the voltage on the secondaries (16.5+16.5)*76 or am I a complete moron? Also the primaries are parallel are they both 120 V or are they 60 V each thanks in advance.

I want to create a LED grow light but i am having trouble with the math. I have 5 blue LEDs that are 3w( Vf: 3-3.4 v and If:700ma). Now i want to wire these in a series. So if i were to use two of these for example, would it require more volts and the same current. So: 2@3v = 6v @700ma. 

Where can i buy knex iwill be giving out free 5 star rating to the first person who ansers this question1

Here are the specs of the bulbs. Parameter Typ Max Unit Luminous Intensity 4180min 10000 mcd Viewing Angle 24°~30° 23° Deg Forward Voltage 3.3- 3.6 V Reverse Voltage ~ ~ V Forward Current 20 mA Wavelength ----nm Operating Temperature Range -40°C to -80°C Storage Temperature Range -40°C to -80°C Lead Soldering Temperature(4mm from body) 260°C for 5 seconds Datasheet Download Color?

I have a 4 battery pack  i want to use for an usb charger i need ro know what diode i need to use the battery pack gives off close to 6 v but i have a USB DC-DC Converter 3V to 5V 1A Adjustable Step-up Boost Power Supply Module. I know i need a diode i need so that the current from what  im chargeing does not go back into the battery but at the same time i need the batteries to give off as close to 5 v that it can work with the module. what i need is which one can i use to so this?