Hello. Can anyone show the 12v power supply with overvoltage protection. I really need it.

 

That is hard to do. You do not state your power source or the required output current. If it's low current, the data sheet for a 7812 (use LM7812 as a search term) will bring up what you need. The overcurrent is a bit crude, though - if it gets too hot, the pass element shuts down.

 

He wants overvoltage protection. Overcurrent was not mentioned.

 

Overvoltage protection is typically accomplished by using an SCR crowbar circuit. I could describe the technique here, but there are numerous articles describing them available on the Internet. Google is your friend.

 

but i didnot found any. give me schema with components pls

 

but i didnot found any. give me schema with components pls

This is homework. We don't give away answers here. You have to show your work, and tell us where you are getting stuck.

What are you entering into your search engine? There are lots of free answers on the web.