نویسنده: احسان شهنازی

Tip42 – Tip42
BD534 – 2n6124
BD536

bc153
bc157

A940-2SA940-KSA940-CSA940

محاسبه Rsc

Rsc = VbeQ2 / Isc

Vbe is the base emitter voltage of the transistor Q2. Typically 0.6V.
Isc is the desired short circuit current.

When current increases above that threshold, Q2 will start to conduct and will divert current away from the base of Q1, thus preventing the output current from rising.

Using emuler 0.6V & my 1.501A will give a result of

wait for it (calculator really crunching the numbers)

Rsc= 0.39973351099267155229846768820786 ohms = 1ohm

Problem solved for nezarati.ali 😛 🙂 😀 😉

ps if going this path be sure to heatsink both regulator & series pass PNP transistor very well as others mentioned above

از لینک زیر ترانزیستورهای با جریان کلکتور1 امپر از نوع PNP را میتوانید مشاهده کنید

https://alltransistors.com/crsearch.php?mat=Si&struct=PNP&pc=&ucb=&uce=&ueb=5&ic=1&tj=150&ft=3&cc=0&hfe=40&caps=TO220&r1=0&r2=0&r1r2=0

 

ادامهٔ «انواع روش های راه اندازی رگولاتورهای سری LM78»