Giorgos Lazaridis writes:
Some time ago I presented a small circuit with the MCP1640, the High Efficiency Battery Boost Regulator using the MCP1640. My original intention was to combine it with this one and make a complete power supply unit with SMPS technology, dual voltage output, battery charger and power failure signal output. And here it is!
SMPS with Battery Backup and NiMH Charger using the LM2595 - [Link]
Giorgos @ PCBheaven build a MCP1640 boost converter for the next LED light project. This converter can be used with almost dead batteries and will squeeze any remaining energy from them. [via]
What i want now, is something to spice up this hack. So here is what – I used the MCP1640 boost converter to drain the last electron from the batteries. This chip can work with a ridiculous low voltage and provide enough power to drive a couple LEDs. Which means the 2 AA batteries will operate even longer and the LEDs will be much brighter.
High efficiency battery boost regulator using the MCP1640 - [Link]
I was on Show and Tell two weeks ago and I demonstrated my project called AASaver. Thanks a lot for providing this great opportunity for DIYers to talk about projects. Here are some details about my project, in case you find it interesting to post on Adafruit blog.
What is the AASaver? Simply speaking, it is a small boost regulator (based on Microchip’s MCP1640) that converts the voltage from two AA batteries to a selectable 3.3V or 5V, which you can use to power breadboard xperiments or use directly as LED flashlights. My main motivation to work on this project is that I have collected a large bin of old AA batteries that have been reported ‘dead’ by various gadgets like remote controls, computer mouse, keyboard, smoke alarm etc. I measured the voltages on them and found that they still have quite a bit of juice in them. So I thought about designing the AASaver circuit to help me harvest the remaining energy in these batteries.
The AASaver has on-board high luminance LED lights, which make it directly usable as an LED flashlight. The brightness can be changed by switching between the two votlages. I have a number of these around my house: they are all powered by almost ‘dead’ batteries. As a flashlight, they can last for a long time. I also want the circuit to be dual-purpose — I designed pin headers that match standard breadboard, so I can plug it directly into a breadboard for my circuit experiments that require 3.3V or 5V supply. I find this really convenient as it only needs two AA batteries instead of a DC power adapter. Of course, for breadboard power supply, you will get higher current output if using fresh batteries.
The details of the project can be found at: http://rayshobby.net/aasaver
AASaver – a small boost regulator - [Link]
Are you looking for a portable breadboard power supply with a selectable voltage? Also thinking about how long the batteries will last? This project utilizes one or two AA/AAA batteries to generate a preselected voltage of 5V or 3.3V, and squeezes the batteries untill they have almost no power at all. AASaver is based on the Microchip MCP1640 boost converter. [via]
When your electronic devices report that the batteries are ‘dead’ and need to be replaced, do you ever feel frustrated that there is often still a lot of juice in them? Don’t throw away the batteries yet! You can use the remaining energy to do a lot of things, such as powering LED flashlights. This is possible by using a boost converter, which can bump the low battery voltage to a higher voltage, enough to light up LEDs or even power breadboard circuits.
Squeeze the power out of batteries using AASaver - [Link]
The design is based around the MCP1640 IC. It is a 350mA 500Khz boost converter with an integrated switch. Due to it’s design the device requires very few external components to function. One Inductor, two capacitors, and two resistors are all that is needed.
The efficiency ranges from 60% to 90% depending on the load and input voltage.
Single battery boost converter - [Link]