# Basic Electronics (Page 6)

basic electronics, tutorials.

## Category Engineering – Wikibooks

Category Engineering – Wikibooks

This category contains a number of subcategories, books, and pages related to engineering in general. Books can be found on the Engineering Bookshelf. Courses can be found at Wikiversity:School of Engineering.

Subcategories include specific engineering disciplines, including Electrical Engineering, Computer Engineering, Mechanical Engineering, and Civil Engineering. Also, some books that are general to all disciplines are listed here.

• Analog and Digital Conversion, Automatic Control Engineering, Automotive Systems.
• Basic Electrical Generation, Basic Electricity, Biography of Nikola Tesla.
• Circuit Idea, Circuit Theory, Communication Systems, Control Systems.
• Digital Circuits, Digital Signal Processing, Electronics, Embedded Control Systems Design
• Embedded Systems, Practical Electronics, Power Systems Analysis, Design, and Control
• Microprocessor Design, Engineering Tables, Semiconductors, SensorNetworks

and many more at Wikiversity

## Tables and Charts for Electronics

Tables, charts, quick reference cards, booklets and handbooks; are the most versatile tools of learning and putting the learning into applications. These should not have a lot of language or flowing text. These are – to the point, easy to remember, graphical, colorful (memory aid).

Electronic Tables and Charts

Just like a circuit diagram, flow chart or ladder logic can graphically interface with a human mind, Tables and Charts easily embed into ones memory.

## Transformers Series and Parallel Connections.

Series and Parallel Transformers

Series and Parallel Connections in transformers. Observe the Dot-Polarity. When windings are in parallel the current capacity doubles. When windings are in series the voltage doubles. Wrong dot polarity in series connection just cancels the voltage and a small residual imbalance voltage remains. If wrong polarity connection is done in parallel, then a short circuit or overload may occur.

Basic Electrical Circuits

Center Tap Transformer

This is when you need to build a symmetrical dual supply like +12V and -12V supply for an opamp design.
This is also good for a two diode full wave rectifier. But when you make a dual supply use a bridge and the center tap is ground. If you use just two diodes then one winding may be loaded more than other. That may not be good for long term transformer life. The core may get magnetized.

## Relays and Contactors

Contactors are used to switch Mains voltage. even three phase power to Motors, Heaters and other Actuating Elements of Industrial, Home or Energy Automation. The Types below. They carry high currents and hence are mounted on Panels and Sealed Enclosures.

What is a Relay – Jim Asks

Top three images –

Smart Contactors. Timer, Thermostat. Over Current or Voltage. Trip or Limit. Three Phase Trip. High Power. Solenoid hammer.

Power Contactors. High Power. Nut-Bolt Mounting. Solenoid hammer. Special Contacts. Special Plastics. Heaters and Motors.

Din Rail Contactors. High Power. Easy Replace Rail Mount. Solenoid hammer. Heaters and Motors. Modular, Stackable. SCADA, Control Panels.

Bottom Three images – Relays are much smaller, they are power switching relays and signal switching relays. They are mounted on PCBs or on cabinets/enclosures.

Then we have power relays, like the three above. They may be mounted on PCBs or Inside the Cabinets. They switch currents upto 5 Amps and voltages upto 230V. These are used in Home Automation and in Instruments. The Signal from these drive Contactors in Large Power Systems.

The PCB Versions should not be used for high currents, use for signalling contacters or driving Lamps and Hooters in Annunciation and Alarm systems.

Medium Power. Solder Terminations. Panel Mount. Solenoid hammer. Low Cost. Time Tested Design. Commercial.

Low Power DPDT. PCB Mount. Solenoid hammer. Visual Isolation. Switches Two Loads. Industrial.

Low Power. Small Footprint. Solenoid hammer. Communications. Appliance Control. Low Cost.

In image below – see top three images

Medium Power. Panel or Rail Base Mount. Solenoid hammer. Visual Isolation. Easy Replace, Plugin. Industrial.

Medium Power. PCB Mount. Solenoid hammer. Visual Isolation. Switches Two Circuits. Industrial.

Low Power SPDT. PCB Mount. Solenoid hammer. Visual Isolation. Controls Contactor. Industrial.

Bottom three images are Analog or Digital Signal Relays, means very low current, Low voltage. It is used in Instrumentation, Communications and circuit multiplexing.

Micro Power. Telecommunications. Analog Signal Switch. Low Capacitance. Low Inductance. Reed Relay.

Micro Power. Analog Signal Switch. Small Footprint. Reed Relay. Instrumentation. Communications.

Micro Power. Analog Signal Switch. Small Footprint. Reed Relay. Communications. Low Ripple Pickup.

Choosing a relay–  A relay is an electrically operated switch. Current flowing through the coil of the relay creates a magnetic field which attracts a lever and changes the switch contacts.

Relay Timing –   The text covers electronic circuit to sequence and speed separate relays (like dual vacuum relays) and describes how to sequence mechanically ganged contacts like those in open frame relays.

Relay – Wikipedia  – A type of relay that can handle the high power required to directly control an electric motor or other loads is called a contactor. Solid-state relays control power circuits with no moving parts,

## The Incredible and Versatile 555

The Incredible and Versatile 555 :

These are some 555 circuits, The most versatile and simple chip of all time !. Some 555 circuits with source in the Cadsoft Eagle format are also here for editing and learning.

The best part of the 555 is that it has an voltage detection. It has a Versatile Logic which is defined by voltage comparators. The ability to loop it like an opamp for feedback makes it the first “Programmable” Mixed Chip. In short it make an ideal building block.
Its drive is amazing, it can power small solenoids, lamps and relays. It is a Symmetrical output drive, means Source – push the pectrons into a node and Sink – pull the pectrons from a node. Conventional current is opposite to the flow of electrons. Current flows from positive to negative, so let me use a new word pectron, imaginary ‘+’ electrons, not Positrons.

Tutor Gadgets for 555

Circuits

Signetics made the 555, This is one IC that is like a E-LEGO, this along with Op-Amps and other components can make many interesting projects. On some pins like Control Voltage it responds to analog signals and on Reset and Output the signals are Digital like. The 7555 a CMOS version consumes lower power and oscillates at higher frequencies.

NE555 Applications and Specifications

“Study .. Learn .. Examine.. Experiment .. Analyze .. Establish .. Realize”

– Solderman 1658

## Digital and Logic Circuits Basics

Digital Logic :

You can start learning digital circuits by learning the operation of logic gates, see an interactive gadget tutor Logic Gates.

Then you can test the basics with these tutor gadgets

Timers and Counters along with Analog Process Controllers formed the front end of Industrial Automation. Even today automation systems and control panels use analog timers and electromechanical counters. These are Indispensable. Analog + Digital combination controllers came next which were little bigger and offered better stability. They had thumbwheel switches as user interface in place of potentiometers.

uP based Systems with chips like 8085 came after that, they consumed more power and were big in size. The coming of Cmos uC like 80C31 made Process Instrumentation Small and SMD made even 48 X 48 DIN sizes possible. Now Analog and uC based designs are used in different applications. Digital Hybrids and uP instruments are not used as they were Transient-Technology Methods.