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: 
Here you go. But a 555 would be easier, require a smaller capacitor and it might be easier to explain how it works. 

![schematic](https://i.stack.imgur.com/bi5TW.png)

[simulate this circuit](/plugins/schematics?image=http%3a%2f%2fi.stack.imgur.com%2fbi5TW.png) – Schematic created using [CircuitLab](https://www.circuitlab.com/)
It is possible to create a light flasher using just a heating element and a bimetallic strip. It's likely to be horribly inefficient, but it can be made to work.

And there's not even a transistor needed.

There's an example here [Evil Mad Scientist](http://www.evilmadscientist.com/2008/easy-high-power-led-blinking-circuit/) using a blinking incandescent lamp, of the sort sometimes used in Christmas decorations.

![schematic](https://i.stack.imgur.com/B5lLL.png)

[simulate this circuit](/plugins/schematics?image=http%3a%2f%2fi.stack.imgur.com%2fB5lLL.png) – Schematic created using [CircuitLab](https://www.circuitlab.com/)