Timer LM555 Circuits
The described circuit utilizes an LM555 timer IC configured in astable mode to generate a timing sequence suitable for sports events. The primary function of this circuit is to alternate between two outputs: a GREEN LED that remains illuminated for a duration of 3 minutes and a RED LED that lights up for 1 minute, creating a clear visual indication of the timing cycle.
The timing intervals are determined by the resistors and capacitors connected to the LM555 timer. The first timing period for the GREEN output can be achieved by selecting appropriate resistor values (R1 and R2) and a capacitor (C1) to set the duration to 180 seconds (3 minutes). The RED output timing is similarly configured, requiring a different set of resistor and capacitor values to achieve a 60-second (1 minute) duration.
A buzzer is integrated into the circuit to provide an audible signal at each transition between the GREEN and RED states. This buzzer is activated through the output pin of the LM555, programmed to sound for approximately 2 seconds each time the output changes state.
To enhance user interaction, the circuit includes push buttons that allow the user to stop, reset, and start the timing cycle. These buttons are connected to the reset pin of the LM555 timer, enabling the user to control the timing sequence easily. When the reset button is pressed, the timing cycle is halted, and the outputs revert to their initial state, ready for a new timing session.
Overall, this LM555 timer circuit provides a simple yet effective solution for timing sports events, combining visual and audible signals to enhance user experience. Proper selection of components and careful layout design will ensure reliable operation throughout the intended use.The following are LM555 timer circuits that have unusual functions. Designed to time a sports event; In this circuit the GREEN output is adjusted to be on for 3 minutes and then the RED output is set for 1 minute in a repeating cycle. Each time the light changes a buzzer will sound for about 2 seconds. The timing cycle can be stopped and reset/started with the push buttons shown on the schematic. 🔗 External reference
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