請教師兄12v轉1.5v火咀電電路

請教師兄12v轉1.5v火咀電的電路可否給小弟,小弟想整來玩下

use IC LM317 - programmable voltage regulator ?

原帖由 rk2 於 2008-8-14 01:30 PM 發表

                               
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use IC LM317 - programmable voltage regulator ?

好熱

原帖由 ice1234 於 2008-8-14 15:54 發表

                               
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好熱

Yes, 12v 降至 1.5v 應該會好熱 , 不過我唔識其他方法啦

原帖由 rk2 於 2008-8-14 06:07 PM 發表

                               
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Yes, 12v 降至 1.5v 應該會好熱 , 不過我唔識其他方法啦

BUCK CONVERTER 先係王道
低熱高效能

yes, hear about this, any reference material for further reading  ?

原帖由 rk2 於 2008-8-15 10:22 AM 發表

                               
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yes, hear about this, any reference material for further reading  ?

http://www.datasheetcatalog.com/ ... /G/3/5/SG3525.shtml
http://www.datasheetcatalog.com/ ... /C/3/AMC3843B.shtml
www.microsemi.com/micnotes/1302.pdf

其實你只要上google 是旦打buck converter 就有一大埋 reference material可以睇..
buck converter 線路十分簡單,但要注意 closed loop ｓｙｓｔｅｍ　ｄｅｓｉｇｎ這一環.
error amp　大多數分為三種　ｔｙｐｅ　１，２同３．　各有所長．．．． 用邊隻要睇你個buck converter 行咩ｍｏｄｅ．．．．．（ｃｕｒｒｅｎｔ　ｍｏｄｅ ///voltage mode???)

另外,用 dual loop control(external loop: voltage, internal loop :current  )會比 single loop control 來得好, 用dual loop control 只要用兩個普通PI controller 或其他controller就可以做到很好o既效果.....如果用埋loss-less current sense technique簡直係無得彈

[ 本帖最後由 ice1234 於 2008-8-15 14:19 編輯 ]

Find this in Wikipedia   :

A buck converter is a step-down DC to DC converter. Its design is similar to the step-up boost converter, and like the boost converter it is a switched-mode power supply that uses two switches (a transistor and a diode) and an inductor and a capacitor.

The simplest way to reduce a DC voltage is to use a voltage divider circuit, but voltage dividers waste energy, since they operate by bleeding off excess voltage as heat; also, output voltage isn't regulated (varies with input voltage). A buck converter, on the other hand, can be remarkably efficient (easily up to 95% for integrated circuits) and self-regulating, making it useful for tasks such as converting the 12-24V typical battery voltage in a laptop down to the few volts needed by the processor.

i got the compete circuit... and the current can be tuned as well... I'm not in hk now.. PM u later