Michimartini from Hackaday.io enjoys tinkering with multivibrator circuits and has explored a simple ring oscillator example. Comprising five identical stages, this discrete transistor RC-delay design showcases each stage with a transistor responsible for capacitor charging and discharging. The inverted signal is passed to the nearest neighbor, with an extra transistor in place to invert the signal for LED illumination. This ensures a visually pleasing effect, as all LEDs light up except one.
To comprehend its functioning, comparing this design with an astable multivibrator is insightful. Essentially, the circuit takes the classic astable multivibrator and replicates it, distributing the low pulse across more stages. Though conceptualizing it as a single stage is challenging, incorporating neighboring stages clarifies its behavior.
However, michimartini notes an initial chaotic startup for the circuit, requiring a brief short to a transistor for stable rhythmic operation. This intriguing start-up behavior, coupled with timing alterations due to voltage and temperature changes, adds to the circuit’s appeal. The organic traces and captivating visual effects make it suitable even as a pin badge. Furthermore, minimalist blinky designs, including incredibly small versions, underscore the fascination and creativity inherent in these types of circuits.
Have a look at the LED boards that PiShop offers and check out our blog for some ideas on how to use them, might I suggest:
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