“This is a simple ring oscillator.
Each of the three transistor circuit work as an inverter and the oscillation is made possible with a feedback loop.
Parts: general purpose bipolar junction (BJT) NPN or PNP transistors - 5 (you might need spare just in case), 10 kohm resistor - 5, 100 ohm resistors - 5, 1 kohm resistors - 5, 470 uF capacitors - 4, matrix board - 1 (10 cm by 10 cm), insulated wires.
Tools: pliers, wire stripper.
Optional parts: solder, heat sinks, heat transfer paste.
Optional tools: soldering iron.”