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this circuit diagram is used to convert a momentary switch to toggle function , how can i extend the diagram to get three output stats to switch between two LEDs and an off state if it possible

  • 1
    \$\begingroup\$ Use a microcontroller. Simpler. \$\endgroup\$
    – Passerby
    Commented Jun 9, 2020 at 7:00
  • \$\begingroup\$ can you explain what output states you need? it seems that with 2 LEDs you should be able to get 4 states, not three. \$\endgroup\$
    – RJR
    Commented Jun 9, 2020 at 9:53

1 Answer 1


There's no easy way to extend the toggle circuit to three states. Instead, use the 555 to debounce the pushbutton, and then use its output to clock a three-state FSM comprising a pair of DFFs and a NOR gate.


simulate this circuit – Schematic created using CircuitLab


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