DC-DC step down circuitry

[Mac7978]

dc/dc step down with zener

Dear all,

Can anyone provide me a circuitry to "step down" DC 12V to 5V by just using BJT transisotrs?

Thanks a lot

 

[qutang]

u can design it by yourself

 

[mister_rf]

Do you need to simulate a full DC_DC convertor using only BJT (lots of BJT ) or just using a normal dedicated controller and some externals power BJT?
Like here:
**broken link removed**

 

[poweric]

could you tell me why you only choose the BJT buck
? how do you consinder this application

 

[Rahul_d]

You can use a LINEAR DROPPER by using NPN BJT with a zener & a bias resistor at the base to clamp the base at 5.1 so emitter will float at 5.1V-0.7V = 5.3VDC aprox.

 

[mister_rf]

Here you find some examples of ''step-down'' circuit 12V to 5V using ONLY
BJT transistors

https://www.romanblack.com/smps/smps.htm