USB Charger... - Electronic Circuits Projects Diagrams Free

IanHam · 4th August 2008, 04:24 AM

Well I have a candy tin and wanted to put a 9v (battery) input and a 12v (car) input. And have it go out to a female USB port. I need one of these http://www.thesource.ca/estore/produ...ine&tab=1#more So it will regulate the voltage to 5v. It is rated for 5v to 18v so I figured no problem having 2 input voltages (only going to use one at a time of course) and would have a switch so you can select 12v, 9v or off. I would like to include a on LED so I figured I would put that behind the voltage regulator. Do you think this is possible do I need any capacitors to keep the power "clean"?

Any help would be appreciated.

House0Fwax · 4th August 2008, 05:43 PM

A 9v battery won't power the 7805 for very long.
12v on the other hand is a much better idea.

As for capacitors and a LED, have a look at the following link.

http://electronics.howstuffworks.com...ectronics4.htm
HowStuffWorks "How Electronic Gates Work"

IanHam · 4th August 2008, 06:19 PM

I gave a few capacitors laying around a .33uf a .1uf and a 10uf what ones would you recommend or do I need to go buy some?

justDIY · 4th August 2008, 07:09 PM

wow ... I thought I'd see a lot of web based rip-offs in my day, but Ripoff-City charging $3.99 for a single voltage regulator, wtf!

here's the same part from Future (they're Canadian), $0.15:

http://www.componentsuperstore.com/s...VLSIPEX3276375

I'd recommend you find a Cig lighter to 5v usb charger on the intertubes somewhere, and modify it to accept a 9v battery and a switch. Most of your 12v to 5v usb chargers use high efficiency switching regulators to drop the 12v down to 5v, so they operate a lot cooler. The same regulator will also accept 9v from your battery and drop it down to 5v as well.

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4th August 2008, 04:24 AM	(permalink)
IanHam	USB Charger... Well I have a candy tin and wanted to put a 9v (battery) input and a 12v (car) input. And have it go out to a female USB port. I need one of these http://www.thesource.ca/estore/produ...ine&tab=1#more So it will regulate the voltage to 5v. It is rated for 5v to 18v so I figured no problem having 2 input voltages (only going to use one at a time of course) and would have a switch so you can select 12v, 9v or off. I would like to include a on LED so I figured I would put that behind the voltage regulator. Do you think this is possible do I need any capacitors to keep the power "clean"? Any help would be appreciated.

4th August 2008, 05:43 PM	(permalink)
House0Fwax	A 9v battery won't power the 7805 for very long. 12v on the other hand is a much better idea. As for capacitors and a LED, have a look at the following link. http://electronics.howstuffworks.com...ectronics4.htm HowStuffWorks "How Electronic Gates Work" Last edited by House0Fwax; 4th August 2008 at 05:44 PM. Reason: Typo

4th August 2008, 06:19 PM	(permalink)
IanHam	I gave a few capacitors laying around a .33uf a .1uf and a 10uf what ones would you recommend or do I need to go buy some?

4th August 2008, 07:09 PM	(permalink)
justDIY	wow ... I thought I'd see a lot of web based rip-offs in my day, but Ripoff-City charging $3.99 for a single voltage regulator, wtf! here's the same part from Future (they're Canadian), $0.15: http://www.componentsuperstore.com/s...VLSIPEX3276375 I'd recommend you find a Cig lighter to 5v usb charger on the intertubes somewhere, and modify it to accept a 9v battery and a switch. Most of your 12v to 5v usb chargers use high efficiency switching regulators to drop the 12v down to 5v, so they operate a lot cooler. The same regulator will also accept 9v from your battery and drop it down to 5v as well. __________________ If you don't have a planet, what good are gold bars? want to contact me directly? gmail gordonthree check out my project website: http://projects.dimension-x.net Favorite numbers: 09 F9 11 02 9D 74 E3 5B D8 41 56 C5 63 56 88 C0