I need squarewave to run this circuit (2-4-6-8 up counter) but i don't have generator. Is there any way to create square wave from DC battery? Or is it necessary to use square wave?

 

Certainly. Use the three remaining NOR gates to create an oscillator.

 

With the post #2 'differentiator' circuit, V1 gets driven both above and below the supply rails, so care must be taken to ensure R2 has a high enough value to limit the input current to the first gate to a safe level. The circuit also has two stable states which it can get stuck in.
Here's an alternative 'integrator' circuit which avoids those situations :-

 

From a TI CD4093 datasheet:

If you don't want a control input, you can tie the two inputs together or use a single inverter from a CD40106. You may need to buffer the output in some cases.

 

From a TI CD4093 datasheet:
View attachment 201627
If you don't want a control input, you can tie the two inputs together or use a single inverter from a CD40106. You may need to buffer the output in some cases.

So if using the RC circuit time constant, and just duty cycle calculations, these types of circuits can be solved, since the well working op-amp's take care of the details.

So you don't have to do any crazy transistor models.


I've been avoiding playing with digital chips, like making osc., but I'll remember that , thanks dl324

 

A 555 timer?

 

So you don't have to do any crazy transistor models

A CMOS Schmitt inverter only takes 6 MOSFETs. I haven't tried making one from discrete MOSFETs, but have used the MOSFETs in a CD4007 to make one. May try making one with discrete devices now that I have some complementary MOSFETs.