Friday, December 16, 2011

Mobile Phone Battery Charger

This battery charger circuit is for Sony Ericsson standard batteries, Li-Polymer type, with a nominal voltage of 3.6V and a capacity of 900mAh. But you can also charge Nokia batteries as well.

Charging lithium cells is fairly straightforward. You generate a well regulated voltage and ensure the charging current is sufficiently low so as not to cause overheating problems. Also, when the correct terminal voltage as been attained, it is important to shut down the charging process at that point.

Friday, December 9, 2011

Low Cost Capacitive Touch Switch II

In my previous post of capacitive touch switch, it gives the o/p as long as you touch it. Means it was only drive the load when you touch it, and when you remove your hand/finger then it was not able to drive the load. Tough that touch switch circuit can be used in various apps but does not meet my requirements. So by changing the circuit a little bit i am able to design a touch switch that behave like a normal switch i.e touch to on and touch to off.

Wednesday, December 7, 2011

Low cost Capacitive Touch Switch

Common designs for touch switch switches detect a decrease in resistance either when a user's fingertip connects a contact to the circuit's common ground. The circuit shown operates by sensing an increase in capacitance that results from touching a contact. Although a straightforward design might require a complex circuit, the design shown offers a low-cost approach that uses few components.

Friday, December 2, 2011

PICkit 2 Clone

There are many PIC programmer available, commercial and DIY devices. As Microchip introduces the new microprocessors the programming software got to be updated accordingly playing catch-up with the PIC manufacturer. That is the root of the problem with third-party PIC programmers. Microchip's PICkit 2 is the low cost ICSP programmer for Flash PICs with USB interface introduced by Microchip. Only subset of PIC microcontrollers is supported, but the list is including all the recent devices from PIC16, PIC18 and PIC24 families and certainly covers all the PICs you are most likely want to use. It is fully integrated with Microchip’s MPLAB IDE and allow not only program but debug applications as well.