USB Car Charger
Intro: USB Car Charger
This is a Home Made Usb charger with this device you can charge in your car any Usb charged device like mobile phones, bluetooth headsets, Gps , cameras, mp3 players, etc..
This device I made haves 0.5Amp output that is the normal power output on a computer, if you use a bigger transistor you can get more output amps.
This device I made haves 0.5Amp output that is the normal power output on a computer, if you use a bigger transistor you can get more output amps.
STEP 1: Parts & Tools Needed
This are the parts needed to assemble this home made USB charger:
Parts:
-cigarette lighter plug
-Usb female Port (taken from a old computer Motherboard)
-5V regulator, 78M05 or 7805 (taken from broken playstation, you can take from other broken device or buy)
-resistor 100 Ohm or 220 Ohm
-led
-wire
-Heat Shrink Tubing
Tools:
-Dremel
-Solder Iron
-Solder lead
-Solder Paste
-Hot Glue Gun
-multimeter
Parts:
-cigarette lighter plug
-Usb female Port (taken from a old computer Motherboard)
-5V regulator, 78M05 or 7805 (taken from broken playstation, you can take from other broken device or buy)
-resistor 100 Ohm or 220 Ohm
-led
-wire
-Heat Shrink Tubing
Tools:
-Dremel
-Solder Iron
-Solder lead
-Solder Paste
-Hot Glue Gun
-multimeter
STEP 2: Schematic
This is the schematic
The standard 7805 was to big to fit inside my cigarrete lighter plug.
So i used the 78M05 a SMD transistor because is smaller then standart 7805, and haves 0.5A that is enough for the USB charging.
The standard 7805 was to big to fit inside my cigarrete lighter plug.
So i used the 78M05 a SMD transistor because is smaller then standart 7805, and haves 0.5A that is enough for the USB charging.
STEP 3: Cigarrete Lighter Plug Drill
I made this holes with the Dremel to fit the the USB female .
STEP 4: Soldering Parts
In this pics I show the transistor and wire setup
STEP 5: Soldering Led's
This Pics show final circuit with the Led already mounted
I Used the Heat shrink tubing to isolate some soldering points
I Used the Heat shrink tubing to isolate some soldering points
STEP 6: Fit the Circuit Inside Plug
I this part I used the Hot Glue Gun to glue the Usb Female on the back of the cigarrete lighter plug.
23 Comments
dasuntheekshana 4 years ago
I made that circuit. Its working. I can charge my Bluetooth head set with it. But when I try to charge my phone with it it's heating very mush. What. I can do for it?
RudranandS 6 years ago
For those who are asking about high heat dissipation or unable to charge
device. LM7805 does not magically converts 12v to 5v. It will
dissipate the 7v as heat. It rapidly changes it's resistance in while
maintaining a fixed ratio of res(7805) : res(load) to Volt(IN)-5v : 5v.
For example if input is 12v and load resistance is 5ohm (i.e. 1A load
current @ 5v), the ratio of resistance will be (12-5) : 5 -> 7 : 5,
thus 7805 will have a resistance of 7ohm when input is 12v and load
current is 1A. At 41.6% efficiency a 5W load will appear 12W load to the
battery. However it is more preferred than efficient SMPS when the
output voltage has to be extremely stable or when energy consumption is
low or when energy is cheaper than the IC itself. For those who wish to make a very simple, cheap & efficient SMPS i would suggest them AD84064 ic or more common 34063 ic (w/ 2 more resistors to add than AD84064).
https://www.aliexpress.com/item/20PCS-AD84064Q-AD8...
https://www.aliexpress.com/w/wholesale-mc34063.htm...
omprakash sahu 8 years ago
How can solve this problem.
Everything impossible 8 years ago
greatmanhar 10 years ago
i couldn't really get it to work....bcoz i have it connected to a solar panel with a 15 volt output...n when i connect it to a phone, it doesn't charge....basically, when there is a load, the voltage drops. plz help
swilliams86 9 years ago
Hi there, I did this same thing and mine didn't work because the solar panel doesn't create enough current to charge my phone...the best bet is to plug it into a 12v power source from a battery or indoor socket adapter and check to see if ti is working; if it does you know why the solar panel will not work.:-) I know it has been a year but hope this helps.
iamdarkyoshi 9 years ago
what about DC chokes and stuff? i dont want my alternator to be feeding into my devices usb. also i would reccomend a computer heatsink, these regulators can put out bonkers heat.
bradix14 10 years ago
Does your charger get REALLY hot? I made one like this and it gets so so hot. It has to dissipate so much engery to take the 12v to 5v... How do you solve this?
sbliven1 11 years ago
nrushton 11 years ago
billpoul 13 years ago
shadleyhax 12 years ago
Berserk87 14 years ago
In order to bring the voltage down to that 5V it releases all the extra in the form of heat, and they get VERY hot at 12V, even though they can go up to 46V.
since an lm7805 is inefficient it will drain your car battery as quickly as if it was a 12V device plugged in, wouldnt recommend using this if your car isnt on.
I took apart a bunch of car charges I have just to find out which ones were the good quality ones, one of them had a lm7805 and it had melted a bunch of the wires, and part of the casing on the inside.
vIRCking 14 years ago
For my practical use is just to charge my bluetooth headset sometimes for that purpose is not going to be a problem.
Thank you one more time for your comment.
Wickedweed 13 years ago
ironsmiter 14 years ago
Guess I'll summarize.
Don't worry about inefficiencies. at max draw, on a 40Ah battery, it'll take 2 weeks, just to drain the battery of charge. Presuming the device is constantly charging.
Here's the math.
Spec sheet for the 78M05 shows a output limit of 100mA. average led, 20mA. Parasitic loss of the 78M05, 8mA. Total MAX load with the device plugged in, 128mA.
40AH starter battery average=40000mAh
40,000mAh(battery)/128mAh(device draw)=312 hours to drain a battery.
Now, With JUST the charger plugged in, you've still got a drain. Close to 30 mAh.
That's pretty significant considering the draw with a charging device. But, it's still gonna take a good long time leaving it plugged in to drain the battery. Consider that self-discharge of a starter battery is 2mAh a day. So, the device alone draws 15 times the energy of unhooking your battery cables, and letting the battery sit in 70F weather. Not too bad :-)
Conclusions
If you're looking for a device to plug in to permanently wire into your car for usb charging, this might not be it. If you're looking to leave your device charging for long periods, with the car off... this might not be for you. If, you want a simple to build usb car charger made from spare parts, and are willing to unplug it when not in use, then This might be for you.
ironsmiter 14 years ago
Normal starter motors look to draw about 150 amps. Soooo...
Trying to start a car in the cold for 2 min burns about the same battery capacity as charging my phones from 0% to 100% 4 times. Since MY average crank time in dead of winter is 15-30 seconds... and I usually charge my phone when it hits 40%... One good crank = 1 phone charge = no a problem in my book :-)
Good job on the 'ible, by the way :-)
Berserk87 14 years ago
Car batterys are made for delivering a lot of amps for a very short time, enough amps to create the spark to ignite the fuel, a constant drain on them damages them and drastically shortens there life.
Also, the LM7805 has a 1Amp output.
ironsmiter 14 years ago
The LM78M05 , not so much.
The small package has "Output current in excess of 0.5A"
with normal heat dissipation, 0.5A is max for that chip.
It CAN be pushed to almost 0.7A with additional heat sinking, but that is
outside design specifications.
You are MOSTLY of right on the car battery issue.
A NORMAL starter battery shows a 135 min reserve capacity(went and looked it up, because of your accurate observation). Reserve capacity is the time in minutes that a new, fully charged battery will deliver 25 amperes at 80 degrees F and maintain a terminal voltage equal to, or greater than, 1.75 volts per cell. Similar to the conditions I described in my initial comment. Netting that battery just over 2Ah@12V. Given that, and a 1A 7805 circuit... you'd have a dead battery when you left work.
MY car battery is actually has 15 Amp Hours at a 20 Hour Rate. For a little light reading on the matter follow this link.
Now, to be fair, MOST people don't use a large truck battery in their 1L subcompact(heck the battery weighs almost half what my engine does! 60lbs vs 118lbs).... and deep discharging with this style battery does shorten it's "expected lifespan under normal usage". HOWEVER, it's not as terrible as you seem to think, especially at low loads, without deep discharge, and with proper re-charge practices(read occasional de-sulfination charge cycles).
To put a fine point on the matter, I actually know a fella that uses starter batteries in his electric car. Sure, "they're totally dead" after 2 years of mild use, but he gets them from the scrapper for the exchange of his old batteries, so essentially free. He uses twice the number of batteries as his wife's car, with deep-discharge golf cart batteries, and doesn't get as far on a charge. But it does work(and hard to beat FREE).
ironsmiter 14 years ago
Grabbed my old starter battery(no treatly kindly during it's life of service).
Charged it up(12.4Volt measured after surface charge was bled off).
Wired a cigarette lighter cord up to a heat-sinked(6 oz of finned alu) 7805.
Grabbed the old 6volt1Amp weed-eater(battery long since dead)
Wired it into the mix.
Velcroed the trigger down(on) and started a stop watch.
Now, the battery manufacturer claims 81 minutes reserve capacity.
So, when new, it should be above 10.5 volt after running that load for just under 3 hours.
MY results... after 6 hours, the battery still showed 12.1 volt left...under load!
So... judging by new battery standards, I burned down from 75% to 25% remaining "safe capacity".Voltage is still rising back up, with the load now disconnected, so I don't know what actual percent burned off through the motor/IC.
All on a battery that is so toasted that it has to be tickle charged(the fast charger return "it's dead. go get a new one" message)
Conclusion : Go for broke.
Unless you already have a battery problem, the 7805 charger circuit isn't gonna make a significant dent, unless something's gone horribly wrong.
P.S. No, there was no danger in running the trimmer like that. It had no string left. I suppose something COULD have melted, and would have smelled bad, but the concrete is fireproof so....