does any one know how to design latch circuit using transistor and R ,C COMPONENET AND ALSO DESIGN COMPARATOR BY TRANSISTOR

 

Here is a good transistor latch. I don't have anything on a transistor comparator right now but you should be able to do a search on line and come up with something. It's all out there, just use Google and you will be surprised.

I have used this and recently so I know it works.

 

For a discrete component comparator check out this site.
Comparator

 

does any one know how to design latch circuit using transistor and R ,C COMPONENET AND ALSO DESIGN COMPARATOR BY TRANSISTOR

Can you tell how many components you want for the latch circuit?

 

can you tell how many components you want for the latch circuit?

it does not matter what ever the number

 

use better title for questions

 

As strantor says, it will help us to help you, if you give your threads a meaningful subject line.
"Need help", "Help me", etc. does not tell us anything that is useful. Worse, it is somewhat annoying to those of us who have been on the Forums for a long time.

"Help on discrete transistorized latch circuit schematic" is very helpful for us.
"Help with discrete comparator circuit" is also very helpful.

 

This is a bistable multivibrator with two outputs. If you only need one, you can bypass the other.

http://www.talkingelectronics.com/FreeProjects/5-Projects/Page16.html

 

Appropriate titles will help in future searches. A LOT.