I am brand new to building circuits, so I apologize if I use the incorrect terminology. I am trying to build an oscillator circuit that will output a Triangle Wave and Square Wave in tandem (trying to dip my toe into building modular synthesizers).
I will try to explain my problem referencing the following pictures:
- Intended Circuit Diagram - The complete circuit I am trying to build
- BC547 Removed - Removed the BC547 Transistor to confirm all other components are working
- BC547 Connected - Re-connected the BC547 Transistor and started seeing inconsistencies
NOTE: I built all simulated diagrams with Falstad Circuit Simulator. The exact circuit I am trying to build can be found at this link. I am specifically referencing the section titled "Oscillator Core".
My main problem is that the simulator and my breadboard are showing different behavior when connecting the Transistor (BC547).
I've narrowed my focus to the Transistor (BC547) because if I test the entire circuit after removing this component, everything behaves identically between the simulator and breadboard:
When re-introducing the BC547, I start seeing inconsistencies between the simulation and my breadboard. In the simulation, adding in the BC547 allows it to start oscillating as intended. However, on the breadboard, my voltage levels remain static (Triangle +11V, Square -10V). I believe I am connecting the transistor with the correct pinout. What's interesting is that I can flip the transistor around and reverse the Collector and Emitter legs in the simulator, and it still oscillates correctly.
I tried to replicate the exact behavior in the simulator, and I found that if I added a ground output to the collector leg of the BC547, the simulation behaved the exact same way as the breadboard.
Apologies if I left out any important information. I've narrowed my focus to the transistor in my testing, so I wanted to start there when asking my question. I will gladly provide any other information if needed. I've included a picture of my current breadboard layout below: