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Monday, March 06, 2017

Good Earthing Prevents Shocks

Good Earthing or Grounding is needed for Human Safety it also Prolongs Appliance Life. Earthing in the olden days was done like this, i have just mixed what i have heard with my common sense and this is what it may be.

Do it professionally, do it with the help of qualified Electrical Engineers. Do not cut costs here.

Make a deep pit, 4 feet deep, 1/2 feet dia, put long copper rods ( GI pipes or lead pipes were also used). Let the copper rods be driven deeper than the four feet that has been dug. mesh the rods with copper mesh or wire (GI chicken mesh). Fill the pit with all the conductive things which are bio-degradable, non-toxic, non-corrosive and non-soluble. They used coal, charcoal, salt, scrap metals. (now they have a polymer conductive gel). Terminate the copper rods to a thick copper wire run it to your mains box in a way it cannot be cut or broken when gardening etc.

Good Earthing Prevents Shocks

The mains box should be fitted with HRC fuses and MCBs as required, use a ELCB too. The MCB trips when a over current load is drawn, there are both thermal (thermostat technology) and electromagnetic (relay technology) MCBs. The ELCB does not have a earth wire, it trips when the current in the live and neutral paths are unequal. When the difference is say 20mA it trips. This 20mA would have gone thru the ground wire or thru a person giving shock. Also use Over Voltage and Under Voltage Trips if possible, Many equipment fail due to this.
  • HRC -- High Rupture Capacity.
  • MCB -- Miniature Circuit Breaker.
  • ELCB -- Earth Leakage Circuit Breaker.
  • GI -- Galvanized Iron
Also do not forget a lightning rod on the top of the house, whose path to ground is far from the earth pit. Lightning also zaps phones etc. Use Zener barriers for all interfaces between equipment and isolation transformers.

Earthing system

Cable TV wires, phone wires, and mains wires all may get mixed up. During rainy days even a phone line or TV cable may give shock or blow input circuits in equipment. This may be due to mains leakage or lightning.

Before you touch any metal object, cross your fingers, better still buy a long neon tester.

delabs Technologies - EE Notes

    Saturday, March 04, 2017

    DC Circuits - University of Guelph

    Start with the Basics like ohms law, resistors, voltage current. Learn the math and equations too.

    Schematic Diagrams, Complicated Circuits, Ohm's Law, Kirchhoff's Current Law, Kirchhoff's Voltage Law, Resistors in Series, Resistors in Parallel.

    DC Circuits - University of Guelph

    DC Circuits - University of Guelph

    Physics Tutorial Menu - Dimensional Analysis, Graphing Oscillating Fns, Torque and Rotational Motion, Simple Harmonic Motion.

    Friday, March 03, 2017

    Phoenix Science Experiments

    Phoenix allows you to develop science experiments  by connecting  sensor / control elements to a computer and access them through software.

    Phoenix Science Experiments

    Phoenix depends heavily on Python language. The data acquisition, analysis and writing simulation programs to teach science and computation.

    Different sensors elements can be interfaced and accessed by few lines of Pythoncode. Phoenix utilizes the power of personal computers for experiment control, data acquisition and its mathematical analysis.

    Phoenix Science Experiments

    PMDK is an easy-to-use, low cost micro-controller development system. The hardware consists of an ATmega16MCU, LCD display and regulated DC supply. All the I/O pins of the MCU are available on sockets.

    The instrument is designed using locally available low cost components and the design is freely available for commercial production. Design supports hardware plug-in modules for expansion. Phoenix is developed using Free Software tools.

    The serial and USB versions can be easily interfaced to a PC. They can also be programmed through the serial/USB ports after uploading a bootloader program to ATmega16.

    Hobby DIY Garage