Usb Power Adapter | Electronic Project Circuits

Posts Tagged ‘usb power adapter’

Advanced USB Device Charger by LT1031

With this tiny thing you can charge almost all devices that are charged via USB, like iPods or mobile phones, with only two AA-Cells!
The reason is quite simple: I am bored of empty batteries (Ipod, mobile phone) while I’am on the go. And the solution with the linear regulator like the “7805″ is in fact very simple, but very unefficient, because: firstly you need a supply that provides about 3 volts more than you need for usb and secondly in most cases the difference between input voltage and output voltage is lost in heat.
The solution for the problem comes from Linear Technology. The most important compenent of the cicuit presented in the next steps is the “LT1301″. This is a small step up converter for to build switching mode power supplys with only a few external components.

The input capacitator should be as close as possible to pin 6 (Vin) of the LT1301!
Keep all cicuit traces short!
Directly tie Pin1(GND) Pin8 (PGND) and Pin3 (Shutdown) togheter and connect it to ground.
Avoid long soldering times for to prevent destruction of components by overheating…

Read more source: http://www.instructables.com/id/Advanced-USB-Device-Charger/
step3/The-Circuit-in-detail/

Be the first to comment - What do you think? Posted by admin - January 8, 2010 at 7:29 am

Categories: Battery charger Tags: USB Device Charger, usb power adapter

USB to 5V SEPIC DC-DC Converter with Short-Circuit Protection

The single-ended primary inductance converter (SEPIC)
shown in Figure 3 IC LT1618 is ideal for applications where the
output must reduce to zero during shutdown. The input
current limit not only helps soft-start the output but also
provides short-circuit protection, ensuring USB device
compliance even under output fault conditions.

Read More. Source: http://www.linear.com