The article now describes how to build a charger controller board and how to program the AVR microcontroller. You should have a LiIon battery you can practice on - my practice battery is still alive and well despite considerable abuse. The more you know about the battery the better: Maximum charge voltage and amps (sometimes printed on the case),
Click here to download the full size of the above Circuit.
thermistor (yes/no and resistance - they are not always 10K) and Smart Battery or not. In addition to the charge controller a DC supply capable of providing at least 2 volts more than the max cell voltage (14. 6 volts in my case) at the desired current is required. At the capacities I want you are out of the "Wall wart" category. I found a laptop supply for a Dell rated at 18V @3. 5A. The board is fabricated using easily obtainable components - refer to the parts list in the Atmel App Note. I made some substitutions and marked the schematic up accordingly. The ATMEGA8 is a new release and has 8K Flash, 1K RAM in a 28 pin narrow DIP package and can be clocked up to 16MHz. If you are willing to eliminate the Smart Battery interface and delete some of the debug code the code could be made to fit in an AT90S4433 as per the original Atmel design. The microcontroller software used is GCC version 3. 2. This version is required to accommodate the direct I/O assignments that resulted from the conversion from IAR that was used in Atmels App note. The software is actually a combination of Atmels, converted from IAR, an I2C interface, converted from 68HC11/Imagecraft and my own GCC code. As a result the program does not read as well as I am used to as 3 different styles are evident. The current / voltage control is managed by a PWM output into a P-Channel MOSFET. A large inductor / capacitor combination is used to stabilize the...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
characters left: