What is a circuit breaker? When do I need an ac power line filter or a phone line filter; How do I design a noise filter; Can I build a homemade surge protection?
The following circuit protection can provide several protections you can experiment yourself at home.

DIY: soldering BGA ICs on PCB in your garage/lab without professional facilities. It is a headache to have a BGA IC mounted on the PCB if it is a small project. Today I want to share something about soldering.

KiCAD a free and open source EDA tool was designed and written by Jean-Pierre Charras, a researcher at "Laboratoire des Images et des Signaux".
The EDA tools are usually under commercial licenses and very expensive. That increases the investment of electronics engineering and brings many other issues. One of my friends used the hacked EDA tools for his projects. Unfortunately, one of the tools was infected by CIH virus and all of his projects on the hard disk were in vain on that big day. It is important to get free (or low cost) EDA tools for electronics engineering.

The application is a disk loader in optical disk driver. This software module controls the motor operation according to the external interrupt from a position sensor. This module works fine independently, but the motor can not stop at the designated position occasionally after integration with other modules.
The engineer checked the code for the motor driver. This code is very simple, which writes port register with H/L values.

This article shows how to set up a procedure for identification of a DC Motor with permanent magnets aimed at digital torque control. In this applications are used: L298 (see the datasheet) - a dual full-bridge driver designed to accept standard TTL logic levels and drive relays, solenoids, DC and stepping motors and ADM3202/ADM3222/ADM1385 - transceivers ideal for battery-powered portable instruments.
The application is divided into two parts:

The printed circuits boards(PCB) for the production, are realized with a finishing process named H.A.L. (Hot Air Levelling) while the prototypes' realization, usually, with a finishing process named "chemical tin". But which are the differences and especially, considering the prices, the process' quickness and the normative in force that bans the lead employment (RoHS), which is the best to be used and why?

16 KEYS capacitive keyboard

This plan was realized in order to be used like a hidden push-button panel to the edge of the monitor. In fact the card has been inserted in a fissure in the wood, therefor hidden, and the activation of the keys happened for a capacitive effect from a distance of 1 cm (thickness of the used wood). The signalling of the pressed key it is sent to a further elaboration device both in SPI format and in UART (to convert in RS232 in order to read the key pressed directly on the PC with Hyperterminal).

Electronic Resistive Key

The code comes established from the value of 3 resistances present in the key.

RX receiver for Rolling code remote controls (Microchip), National and Motorola

IperCODE is a didactic project, with which it is possible to build a remote control acquisition system, based on the rolling codes and to have the possibility to transmit the received code on RS232 serial, to visualize it on the 16X2 display or to reproduce it, transmitting it by radio. Therefore you can make experiments with the peripheral of the PIC16F876 the UART, the Capture Compare, the PWM and the management of the inner EEPROM for saving the received code. The plan can be considered a basic for development, and it can easily adapt to your requirements, as an example, if the inner memory is not enough, it can be connected a I2C or SPI memory on the pin of the micro, left free in that purpose. To import the code you'll have to press the LEARN key for more than 5 seconds or holding the ignition key, while for the transmission of the code you'll just have to press it normally (if you want you can add an additional key).