This simple circuit lets you play the "coin guessing" game electronically.
You flip the coin by pressing the push button switch (S1) for a few seconds. When released, either LED1 or LED2 will remain lit to indicate the outcome (Head or Tail)
Operation : Transistors Q1 & Q2
form a astable flip-flops that generates a stable square wave. When S1 is
pressed, this signal is fed to the bistable flip-flip (Q3 & Q4) which changes
states rapidly & flashes the LEDs continuously. When S1 is released, the
stops & will be latched in of the states. One of the LEDs will be on to show the outcome.