Transistor

Transistor consists of  collector, emitter and base. From the front side of a transistor, the right pin is the emitter. The middle pin is the base and the left pin is the collector. For application with a relay using BC547, the emitter is connected to ground. The collector is connected to relay and diode IN4001. The base is connected to 1K resistor and to the microcontroller.

Operational Amplifier

Operational Amplifier can be used to become comparator. By connecting several resistors, a circuit call comparator will be created. To make a light sensor, LDR or light dependent resistor is used. LDR resistance is very high in dark condition. In bright condition, the resistance will drop significantly. As a result, comparator will use this condition to turn light on when it is dark.

 

Microcontroller

What is a Microcontroller?

Microcontroller Specification

Programming PIC16F877A

Playing with a C Programming and PIC16F877A

Creating a Digital Clock using PIC16F877A, LCD and DS1337 Clock IC from Dallas

How to Load Hex File into PIC16F877A

 

Articles :

Lightning Surge Testing

Bit Error Rate Testing

Insertion Loss Testing

 

Light Emitting Diode

DC Power Jack

Voltage Regulator and Diode

Transistor and Operational Amplifier

Trimmer Pot, Relay and PCB

 

Understanding PIC16F877A

Product Development Using PIC16F877A

More Product Development Using PIC16F877A

PIC16F877A Input Output Overview

Interfacing PIC16F877A With LCD

 

VoIP Basic

VoIP Phone

Using VoIP Through Normal PSTN Telephone

What is Codec?