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Saturday, October 4, 2008

Killed in Ritual

I think this news is a bit scary.
A middle aged couple were killed in “ritual”.
They were having a party (Hari Raya celebration), and the discussion went that the husband (47 years old) seeking helps to make him stop smoking, and his wife (41 years old) were also having asthma and liver ailment. One of their relatives, a 23-year-old male suggested family join forces to beat the husband and wife to death to rid them from their ailments. And the tragedy really happened.
It could be either a mutual agreed situation or a one sided action.
Their heads were smashed on a table, and beaten with broomsticks and motorcycle helmets at his house in Kuala Lumpur.
Ambulance was called within hours, but the couple couldn’t live after the beaten up. Several other family members were also injured.

Further details at http://newsvote.bbc.co.uk/mpapps/pagetools/print/news.bbc.co.uk/2/hi/asia-pacific/7649851.stm
or
http://news.bbc.co.uk/2/hi/asia-pacific/7649851.stm
or
http://ap.google.com/article/ALeqM5hUxHsfRjFDhpOJ3s6ZcyIzzMCeRAD93IQTV00

Buck Converter - Power Electronics Design

Today, I searched for information on Buck-Based Converter. It’s a power electronics design where input voltage is stepped down to a lower voltage to supply to a targeted operational circuit. It’s also known as Switch Mode Regulator or Step-Down Switch Mode Power Supply. This design is good and can be an alternative to Linear Power Supply/Regulator. Switch-Mode configuration is also seen to be more efficient in driving higher power applications.

Here are some links I would like to share. First is this http://www.powerdesigners.com/InfoWeb/resources/pe_html/contents.htm .

It discusses in almost all aspects of the design of Power Supply, from a single diode rectification to buck or boost switch-mode designs, with proper illustration diagrams. I find it quite pleasant, as many discussions are pointed out with graphs and simple circuit diagrams.

Another link to share is this http://powerelectronics.com/power_systems/dc_dc_converters/power_buckconverter_design_demystified/ .
It discusses more on calculations to select inductor, capacitor, FET, etc. to form the required circuit specifications. This website also has contents related to many power electronics design (as it is a website of a Power Electronics Technology).

One of the simple Buck Converter Circuits is here http://www.powerdesigners.com/InfoWeb/resources/pe_html/ch07s1/f05c07s1.gif
A Power MOSFET is preferred to be used as Power Semiconductor Switch in the figure above. It should have fast switching time, and able to withstand high voltage spikes that might be produced by the inductor.

The PWM generator will be the main key to vary the output current, with varying On-Time and Off-Time.

Power Electronics Design is interesting. I actually am not so familiar with power supply design, except normal linear regulation design. I just started to get involved more in power conversion design, and so I have to study more about it. We can't run away from power conversion design, as every electronics design needs power input, and there are many different types of power conversion circuits nowadays.

References:
http://www.powerdesigners.com/InfoWeb/resources/pe_html/contents.htm
http://powerelectronics.com/power_systems/dc_dc_converters/power_buckconverter_design_demystified/
http://www.google.com.my/search?hl=en&q=buck+converter&meta=