Basics On Electronics

There is a very wide range of electronics components available from passive components such as resistors, capacitors, inductors and quartz crystals to active components including semiconductors such as diode and transistors. Thermionic valves or tubes are also used in some specialist applications as well. These and more are all used in electronics and radio circuits today. Surface Mount Technology (SMT) In recent years there has been a drammatic change from the use of leaded components to surface mount technology. These SMT components make the manufacturing process much easier and faster. Introduction to surface mount technology SMT Surface mount technology (SMT) component packages The Ball Grid Array, BGA, package used for integrated circuits Capacitors The capacitor may appear to be simple device at first site, there is more to them than meets the eye. The choice of capacitor can enable the circuit to work correctly... or not. Capacitor marking codes Conversion chart to convert pF to nF to uF SMD capacitors Summary of capacitor types Electrolytic capacitor overview Tantalum capacitor overview Ceramic capacitor overview Silver mica capacitor overview Resistors Resistors come in an enormous variety of sizes. Their markings are known as the resistor colour code and this normally tells their value, and other parameters about them. Resistor colour code Standard or preferred resistor values and the E series Thermistor - the temperature dependent resistor Light dependent resistor, LDR, or photo resistor SMD resistor - the surface mount resistor Semiconductors Transistors and diodes are in widespread use today. Many millions are used each day apart from those that are incorporated in integrated circuits. Basics of semiconductors Semiconductor numbering or coding systems - the Pro-electron and JEDEC systems for diode, transisor and FET codes. Diode types: Introduction to the PN junction and the basic diode Gunn diode IMPATT or IMPact Avalanche Transit Time diode Laser Diode Light emitting diode (LED) Photodiode Avalanche photodiode PIN Diode Schottky barrier diode Tunnel diode Varactor or varicap diode Zener or Voltage reference diode Diac Active devices: The bipolar junction transistor (BJT) Photo transistor (phototransistor) The High Electron Mobility Transistor (HEMT) The Thyristor or Silicon Controlled Rectifier (SCR) Triac Charge coupled image sensor CCIS FPGA - Field Programmable Gate Array ASIC - Application Specific Integrated Circuit Semiconductor Memory Technologies Flash memory MRAM - Magneto-resistive Random Access Memory DRAM - Dynamic Random Access Memory EEPROM SDRAM Quartz Crystals Quartz crystals are widely used in many areas of electronics. Their unique properties make them an ideal choice in many applications Quartz crystals - What are they and how the can be used as a resonator The effects of ageing on the frequency stability of quartz crystals Oven controlled crystal oscillator (OCXO) for greater temperature stability Temperature Compensated Crystal Oscillator (TCXO) Voltage Controlled Crystal Oscillator (VCXO) Quartz crystal specifications and how to specify them for radio oscillator and filter applications Quartz crystal filters: Quartz crystal bandpass filter - filters using discrete crystals Monolithic crystal filter Vacuum tubes Vacuum tubes or thermionic valves are still used today and many can be found in vintage radio sets. (For information about the history of valves and their development see the Radio History section of this website - see side menu). Many audio enthusiasts prefer the sound that comes from a tube amplifier. Additionally there are many valve radios or wireless sets in use, and vacuum tube or thermionic technology continues to be used in some specialist areas of electronics. Basic concepts behind the vacuum tube Descri ptions of the cathode, anode and grid used in the vacuum tube. Vacuum tube or thermionic valve numbering systems Vacuum tube or thermionic valve equivalents for replacements and substitution. Vacuum tube or thermionic valve pin connections - pin connections for some popular valves. Travelling wave tube (TWT) - used for high power microwave amplifiers. Photomultiplier - used for image capture in very low light levels Wire and cables Wire and cable are an important part of any electronic system. While wire and cables may not attract the same attention as other components, wire and cables are nevertheless an important topic. Wire and cable Metric / AWG conversion chart