haro2003

返折型限流 (Fold-back limiting)
如下圖所示的電路，是
一種具有使過載或短路情況
下之輸出電流降低至遠低於
最大負載電流，以避免太多
功率損耗之返折型限流保護
電路。

[ 本帖最後由 haro2003 於 2009-7-16 17:31 編輯 ]

ZZZZZ

http://www.fuzetec.com/resettable_fuse_maine2.htm

PPTC device and Resettable Fuse, very easy to buy in Shenzhen.

Amuro

原帖由 tamkinfigo 於 2009-7-16 09:17 發表
我都想整ga....
最重要其實係short-circuit protection個part
我個sample...不過買唔到d components
各位師兄可以幫幫手找代替品
http://electronics-diy.com/electronic_schematic.php?id=589

SK100, BC548搵唔到....

我估你個circuit唔多work， haro2003在post#10的那個比較正統，參考下啦。

tamkinfigo

師兄所講係short-circuit protection個案part
定係上面個穩壓個part??
因為我只係會用下面short-circuit protection個part

jackli

依個post 已經可以精華佢喇

FireBlack

原帖由 tamkinfigo 於 2009-7-17 23:46 發表
師兄所講係short-circuit protection個案part
定係上面個穩壓個part??
因為我只係會用下面short-circuit protection個part

Your circuit does not seem to have any short circuit protection at all. At most it sounds the buzzer if there is short circuit. Also, your circuit will cause around 0.8V voltage drop, which means 5V output will become 4.2V only.

The circuit by haro2003 is the correct one. It has both current limiting protection and voltage regulation.

tamkinfigo

明白曬....唔該曬甘多位師兄~~