04-10-2012, 10:24 AM
ACCURATE ELECTRONIC STOPWATCH
ACCURATE ELECTRONIC STOPWATCH batch 29.pptx (Size: 377.99 KB / Downloads: 55)
INTRODUCTION
Stopwatches find use as time keeping devices in many fields, namely sports. Stopwatches may be analog or digital. Digital stopwatches are much more common the analog version owing to their higher accuracy and ease of use.
Here we have tried to realize a digital stopwatch of reasonable accuracy and reliability.
Dual decade (0-9) ripple counter
The 74390 contains two separate decade (0 to 9) counters, one on each side of the chip. They are ripple counters so beware that glitches may occur in any logic gate systems connected to their outputs due to the slight delay before the later counter outputs respond to a clock pulse.
RESISTORS
A resistor is a component of an electrical circuit that resists the flow of electrical current.
A resistor has two terminals across which electricity must pass, and is designed to drop the voltage of the current as it flows from one terminal to the next.
CONCLUSION
In a simple LED package, typically all of the cathodes (negative terminals) or all of the anodes (positive terminals) of the segment LEDs are connected and brought out to a common pin