Friday, May 16, 2014

DIY Computing on Raspberry Pi

Raspberry Pi is a Miniature Computer that can Interface with a Display Device like TV and a keyboard.

Raspberry Pi - ARM with Linux Nano Computer

Raspberry Pi - ARM with Linux Nano Computer

Learning Programming with DIY Computing

We now also have a tiny ARM SoC mini computer called Raspberry PI which helps you know how a computer works. Browse the Internet on your TV or learn coding in many programming languages.

(These ARM based devices power many of the small portable electronics we see today.)

Model B is the higher-spec variant of the Raspberry Pi, with 512 MB of RAM, two USB ports and a 100mb Ethernet port. It’s our most popular model: you can use it to learn about computing; to power real-world projects

The Raspberry Pi is a low cost mini computer that plugs into a computer monitor or TV, and uses a standard keyboard and mouse. It is a capable little device that enables people of all ages to explore computing,

Learn on Gadget Hacks and Making Things

A Typical Hardware Hobby Enthusiast is a Hacker when he starts learning, it is sometimes given the name of reverse engineering in another context. The Hardware Hobby Freelance hacker is better off, he is doing it for Learning and Education. Students should be given new and challenging projects in well equipped labs, to augment their skills and make them productive in their jobs from day one.

Hobby Projects - Insulation tester, LED Circuits, Meters.

Hobby DIY Electronics and Making Things at delabs

We all learn by breaking up things, to see how it works, then Fix things around Home etc. Later Create and Innovate perhaps, thats the way to go. To Invent something someday.

Circuit Diagrams Archives Reference

Here are some people doing just that, inspire you to create useful things for your Home. We should never become over dependent on others for everything, this will erode our knowledge base, skills and freedom.

Silicon Chip - Electronics Hobby DIY Magazine, Projects to Build and Kits too.

Nuts and Volts - Aimed at the electronics hobbyist, with articles covering amateur radio, cellular. communications.

Monday, May 05, 2014

UPS Power Inverter and DC to AC

Learn about Power flow, Sags, Dips, Phase rotation, Harmonics, Flicker and more!

Power Quality Teaching Toy

Power Quality Teaching Toy

Standards

CBEMA - Computer Business Equipment Manufacturer's Association adopted curve IEEE Standard 446 (orange book) curve. Recommended Practice for Emergency and Standby power systems for Industrial and Commercial Application."
  • Wave form Sine wave THD (total harmonic distortion) maximum 5%.
  • 3 Phase system phase imbalance of voltage 3% - 6%.
  • Frequency stability 60  +/- 0.5Hz.
  • Output Voltage +6% Max. -13% Min. from Nominal Value.
  • Voltage can fall to 0V but should recover in 0.5 Cycles.
  • On turn on Voltage should reach steady state within two seconds.
  • Upto 200% over Nominal Voltage should be tolerated for 100uS. ( Transients, spikes and Inductive Kickbacks come in this)
  • Upto 30% over Nominal Voltage should be tolerated for 0.5S.
ANSI - American National Standards Institute

"Standard Voltage Ratings for Electrical power systems & Equipment"
  • Steady State Variations +/- 5% of Nominal Voltage. T
  • Three Phase Voltage Imbalance 5% Max..
  • Standard Frequency 60Hz.
Glossary
  • Frequency 60Hz Hz is Hertz.
  • One Cycle = 20mS (milliseconds) one full sine wave.
  • Max - Maximum
  • Min - Minimum
  • uS - micro seconds, S - seconds.
Cause of Transients
  1. Switching Loads Simultaneously (inductive loads).
  2. Power factor correction capacitors and devices.
  3. Lightning strikes (enhanced by earth faults).
  4. Line Inductance (inductive kickback, resonance).
  5. DC and AC Drives for Motors.
  6. Rectifiers with large filters and stray inductance.

CBEMA Guideline
The CBEMA guideline, created by the Computer Business Equipment Manufacturers Association is a realistic, at-the-equipment, maximum allowable voltage that equipment can withstand, without damage or upset.

Hobby DIY Garage