| LEDs indicate at a glance what
the status of the circuit is at any given moment. Once the reset switch, S1, makes
contact, the timer remains in that state until the start switch, S2, is pressed. When
either switch is activated, LED1 (ready) and the time indicator, LED2, keep track of the
situation. Although not necessary, the two LEDs should be of different colors (for
example, red for "ready" and green for "time"). |