Question: I want to make a blinking light for my transformer when I charge anything with it. But as an educational exercise, I don't want to use any kind of IC. Can anyone help me?

Answer: 
The simplest option is just to buy a blinking LED. They have a built in chip that makes them blink.
How about an old-fashioned UJT?

[![enter image description here](https://i.stack.imgur.com/kqkLT.png)](https://i.stack.imgur.com/kqkLT.png)