Problem here is, that the supply is a not current limited and the whole voltage is dropping accross the 0.1Ohm RC of Q4 and the voltage doesn't go down.
Is there a voltage component which behaves like the way I want to? Or what is the right way to simulate a pull down behaviour?
What I want to do, is shorten the supply with the GND when the transistor is in saturation.
Edit 1: For the comments and Arisers answer: After your input I saw that it would be better to name the question: How to design a non ideal voltage source and limit its current.