Challenge 144 doesn’t seem to work very well with a real Spintronics set. I’ve tried making sure all the chains have a good amount of slack in them and verified with the solution it was assembled correctly. The ammeter varies in pitch a lot over time and sometimes even goes silent for random amounts of time or until I nudge the circuit. Has anyone had success with this one with a real kit?
I had the same issue with the it.
If you have the power pack, you can see the effect easier if you replace the 200 resister with the 50, and replace everything shown in the setup from S1 to A1 with just A1. It removes a lot of the added resistance from all the extra junction, switches, and chains. Then you can add some resistance to A1 directly and see the transistor open further and the current staying similar.