i need help with designing a circuit for switching from NPN to PNP or vice versa using single circu

 

Welcome to AAC!
Sorry, but your question makes no technical sense. An NPN transistor can't be converted to a PNP one, or vice versa.
Exactly what are you trying to do and why?

 

What is the problem you are tying to solve by switching between and NPN and PNP transistor?

Bob

 

i need help with designing a circuit for switching from NPN to PNP or vice versa using single circu

Here is the typical PNP-as-a-switch (also known as High Side switching. NPN shown with Low Side Switching.

What are you trying to do?

 

Reverse the polarity of the power supply or battery when substituting a PNP transistor.

(I'm not sure I understand the question.)

 

Must not have been too important.

Bob

 

Either that or he doesn't know how to get back to this thread.