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Make a Human Powered Mobile Phone Charger

Make a Human Powered Mobile Phone Charger

Hi I want to make a mobile charger for my mobile phone See my cell phone doesn’t hold charge for too long And it usually dies right when there is no charger available And I’m in the middle of sending an important text And everyone is waiting for my answer And BAM it’s gone I have to wait for half an hour before I can get off this stupid bus and get into the office to realize they made a decision without me! Again! Now, there is actually a product out there which is basically a backup battery where you can plug your cell phone into it and charge it You’ll have to always keep this battery charged and carry it around with you at all times in case you need to use it FOR GOD’S SAKE, IF I HAD THE DISCIPLINE TO CHARGE ANOTHER BATTERY AND CARRY IT AROUND WITH ME AT ALL TIMES, I WOULD JUST KEEP MY CELL PHONE BATTERY CHARGED! So, I decided to make my own handcranked battery charger But I didn’t want to make a product from scratch So, I decided to use my handcrank flashlight But I wanted to keep this one, so I went out to buy a new one And soon realized that this thing has become a rarity around here All I could find was this little piggy flashlight from Looney Store But right when my daughter realized what I was gonna do to it she said [Mehdi’s Daughter] Dad? Why do you want to kill the thing It still works good… It’s just a piece of junk! [Throws piggy flashlight, laughter] This thing is so low quality, I get to keep it*YAY!* But I’m not gonna use it anyways The little piggy won’t be able to provide enough juice So I open my good flashlight here You can see there is a dynamo and the voltage it creates goes to the FULL BRIDGE RECTIFIER right here And the voltage is later used to charge this tiny battery as well as powering the LEDs This battery is 3.6 volts, having it on the circuit will limit the output voltage to charge a cell phone which needs 5.0 volts So, I have to taken it out *Desolders the battery* I have the charger cable for my phone which I’ll cut open And then I simply connect the positive and negative lines to the outputs of the full bridge rectifier The output voltage of the rectifier is not regulated But I measured once that the cell phone requires somewhere between 300-500 milliamp of current for charging And I don’t expect this flashlight to be able to output that much current So as soon as the cell phone draws the charging current, the output voltage of the rectifier will be limited below 5 volts So it kind of self regulates Let’s give it a try! *starts cranking* There we go, the charger LED is on Now it’s off… Turning much harder now *phone smokes* OH NO NO NO NO NO NO!! NO NO! S**T! I killed the phone! F**K! *Mehdi’s wife enters* [Wife] Did you say you killed your phone?! [Mehdi] No I… [Wife] Did you? Damn it, Mehdi! How much do we have to pay for your f**kups! [Mehdi] I was just making a video… [Wife]All for your stupid videos and FOR WHAT? READ COMMENTS ALL DAY AND GIGGLE? FIVE HUNDRED DOLLARS IS A LOT OF MONEY! WHO’S GONNA PAY FOR THAT? YOUR COMMENTS? [Mehdi] It’s probably nothing, I’ll fix it myself [Wife] Yeah, yeah, and its gonna end up in the pile of things-to-be-fixed Don’t you think I know your routine by now? God! Why did I ever… I made a horrible assumption See, the cell phone started charging and drew current But then, because the charging voltage wasn’t stable enough, the cell phone disabled charging And without any current from the charger, the stupid voltage jumped to something like 20 volts or higher And fried the charging circuit short *throws phone* I guess I’ll fix that later What I need is an efficient 5 volt regulator to add to the output of the bridge rectifier which is nothing but a DC to DC switching regulator Here is a typical circuit of a regulator Fortunately, there are broken prototype boards at work I can cut a regulator from Here we go! Now I solder the regulator to my charger… And it’s done! Let’s check the output voltage See! A nice 5 volt regulated output *Throws charge* Such an idiot, should have done it from the beginning Since I don’t have a phone anymore, I’ve borrowed an old iPhone from my beloved mother-in-law! [Whispers] I’m going to try and charge this one Now, I have to cut the charger cable again And solder these to the output of my regulator… Let’s start cranking! It’s not charging… AHH! WHAT’S WRONG?! Apparently, with iPhones you also need to bias the USB datalines to somewhere around 2 volts. I just need some resistors. I decided to cut a USB extension cord so that I can plug *anything* to my charger! Let’s cut it I solder the connector and the resistors to my regulator… Now, we just shove in and hot glue everything in place And voila! I have a flashlight with a USB charger. Let’s try to charge again! Hey, hey, hey, hey! It’s charging now! [Whispers] Now, let’s try my wife’s new iPhone… Let’s try it out… IT’S WORKING! Can it charge a GoPro? Let’s try it… Oh yeah, it charges everything! It’s a universal flashlight and charger you can take camping with you! I’m a genius, it only took me one cell phone and two charger cables to make this! *laughter, then moans* If you need your hands free to use your phone, you can use your kid! Here you go! Crank away! [Daughter] Why would you plug it here? Hmm? NOOO! *blows cable* [Mehdi Moans]

100 thoughts on “Make a Human Powered Mobile Phone Charger”

  1. I’m probably a little late but making a bike with a crank that charges your light with a usb. So when riding a bike you could have free energy for a headlight and a usb

  2. Your child is absolutely your child! I'll bet she was born with a FULL BRIDGE RECTIFIER already installed. Great video.

  3. Everyone is commenting on how adorable the daughter is. That is, until she decides that she didn't want to be a human slave, so she sticks the usb into some wall outlet thing. I guess the sad look on here face when she realized she did something wrong was kinda of adorable

  4. That's what we like to see.. Equality. It's not fair, shocking yourself all the time. Glad to see you let ELECTROCUTE in on the fun.

  5. what do you use to simulate the capacitor blowing like at the very end? I could tell you triggered something after tour daughter asked the question. I'd really like to know how I could do that as well for projector I'm working on.

  6. Hello Mehdi, I really enjoy your videos. I brightens up my day. On a serious note here, I know you are far from being an idiot and you are a very smart man. With that said I hope that you never get hurt badly doing your videos. I use to work on televisions way back in the day when they had vacuum tubes or " valves " as some call them. They also had very high voltage going to the picture tube (CRT).
    If you were not very careful you could get a good shock from the HV lead going to the picture tube. Great videos my friend, and very informative as well. You make electronics fun, which is what learning is all about, having fun.
    Learning never goes out of style I am almost 70 years old and I'm still learning.

    Be safe and be well.
    Thanks for making these great videos :o)

  7. Well….. Mrs. Mehdi Sadaghdar made a point this time :/
    You always breaks something in every video instead of ours to teach us lessons!
    Keep it up!!

  8. Hehe I'm trying to learn some of electronic just as a hobby I learn from your videos and also have fun. Thanks.

  9. After watching this and blowing the speaker amplifier of my old phone I'm nervous of connecting my phone to everything :v

  10. And then you realize it's the cracking iphone and stops you from charging it everytime it detects the change in voltage of non official charger.

  11. Dude, you're awesome. I learn a lot, but then start laughing so hard I miss some info and have to rewind, which makes me laugh again. It's a shocking feedback loop.

  12. 0:23 If you look closely at the second battery bank, there are some compression artifacts that are staying into the image.

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