Linked Questions

0
votes
3answers
1k views

Why USB wall chargers don't reach their amperage rating? [closed]

recently I bought a power bank that requires 1,6A of charge current. I tried charging it with a 2A Samsung charger, which came with my tablet. Unfortunately it charges very slow. Then I tried another ...
0
votes
4answers
2k views

Creating Li-Ion charger with step up to 700mA from 500mA?

Canon apparently hasn't ever herd of something called USB-charging. The factory AC adapter for this battery(NB-5L) output's 4.2V's at 700mA. Most standard USB chargers output 5V at only 500mA. Would ...
0
votes
3answers
3k views

Three-prong / USB power outlets in wooden desk [closed]

I am trying to mount a strip of three-prong outlets and a strip of USB charging outlets on an old wooden desk. I can handle the carpentry aspect, but I am struggling with the electrical aspect. I ...
3
votes
2answers
626 views

Lengthen a AC to microUSB phone charger cord?

Can I effectively take a 3 ft standard cell phone charger (AC to microUSB, 750 mA at 5V) and lengthen the cord to 6 ft by splicing the cord or am I going to lose something in the mix? Do I need to ...
2
votes
1answer
2k views

Risk of overloading a usb charger

I just bought this product: "Jackson PT1USB" as an attemp to get a portable charger for my netbook, ipad 2 and smartphone. Now I am bit worried after reading in the product "total connected load to ...
2
votes
2answers
361 views

connect LEDs to USB keyboard – but they turn off after a second

I have a USB keyboard. As I work many times in the darkness, I put some LEDs into the keyboard case. I connected two pairs of yellow standard LEDs serially to the USB power lines (Vcc and ground, pin ...
2
votes
2answers
1k views

Convert low power USB to high power USB in car stereo.

Could I connect the D+ and D- to my car stereo's USB input, then connect the red and brown (+/-) to a 2amp cigarette plu'sg USB? My issue is that the USB in the head unit is low power and doesn't ...
-2
votes
1answer
1k views

Can I use my Android tablet charger for the PlayBook? [closed]

I got a BlackBerry PlayBook and it came with the wrong charger plug. It's for the US that I can't use here in Germany. Can I use my Android tablet charger for the PlayBook instead? The information ...
0
votes
1answer
602 views

LM317 to charge a NImh battery from usb [closed]

Hi want to charge my 4000 mAh 1.2V nimh cell battery simply, I do not use them very often. So I wanted to plug this kind of voltage regulator which I think is like that : https://en.wikipedia.org/...
1
vote
1answer
724 views

How to configure USB OTG as power supply

I have an ARM computer with an USB 2.0 OTG port, and I want to use it as 5V 100mA power supply (to drive a couple of leds). However, when I connect a load (LED+resistor) via an OTG cable, the power is ...
2
votes
2answers
443 views

Can you charge a battery to run a device at 5V from the USB port?

Say you had a device that requires 5VDC to operate. It can actually run safely at about 4.8VDC. It normally runs off of USB power but I would like to rig it up to run off of a battery. Would it be ...
0
votes
2answers
122 views

USB powering batteries without OS support?

On a bare-metal project I have in mind, I would like to know if I can avoid to implement the multiple USB specs (O/E/xHCI) and still benefit from usb charging my battery. It will run on a almost ...
0
votes
2answers
139 views

Drawing too little current from PC USB

If I connect this very small load (3 LEDs) to a mains to USB adapter, it's fine. Full brightness, great. I can't even measure the current it's so low. However, if I connect it to my PC it does 3 ...

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