The use of stopwatch timer

Correction is the time by which the hours to be corrected to obtain the correct time. If you are delayed for hours, hours correction is positive, if they go ahead, stopwatch timer correction is negative.

Change in hours for one day is called the diurnal cycle. Positive operation is delayed, negative acceleration operation hours, hours Perfection is assessed persistence time of the day, daily phase difference is called the daily variation. The hours are perfect, the average daily variation of less running.By the Middle Ages used the gnomon, sundials, water stopwatch timers, hourglasses and stopwatch timers fire.

In 13th or 14 century appeared the first time roller. The first tower was a time not only hands and odbíjali. Hands appeared only in the late 16th century. A.D., second only around 1800. In the 14th century appeared the online stopwatch timer. In the 15th century appeared the first interior stopwatch timer. The first pocket stopwatch timer was built in 1510. stopwatch timers appeared in the 17th century, this idea was originated G. Galilei. In the 18th century began to use the unrest that allowed oi produce the first portable timepieces. Electric stopwatch timers were invented around the early 19th century. The first stopwatch timers incurred during the first World War II, the first automatic stopwatch timers were patented in 1924, the first quartz stopwatch timer was built in 1927 (the mass produced since 1969). The first atomic stopwatch timer was made in 1949.

The pendulum stopwatch timers have evolved highly accurate astronomical stopwatch timers, used in observatories. Went through various design changes, the most accurate of them are Shorttove hours.

Current hours are often combined with additional features that are not related to time or (blood pressure monitor, pulse meter, radio, calculator, alarm stopwatch timer, and an informer, weather, altitude measurement, measurement of atmospheric pressure, compass, TV ...)
Drive portable stopwatch timer (meaning watch)

Classic watches are powered by coil spring. Spring had regularly tighten (watch stretching) and its pressure through the transmission (gear wheel) to transmit hands showing time. Initially, craning watch daily, later stretching technology improved and watches require winding about once a week. stopwatch timer hours, just like the big stopwatch timer, determines the pendulum. The wristwatch is used (physical) Maxwell pendulum (ie restlessness). It is stored flywheel rotationally coupled with coil spring. Sprockets are mounted on shafts pointed stored in hard metal housings or precious stones with a hole. The watch was indicated by the number of stones (jewels - jewels). The expensive watch, the more stones.

The invention of the automatic stopwatch timer ("samonaťahovacích" h) allows continuous stretching without special user actions: used stretchy called eccentric weight rotor to rotate according to user's hand movements. Stretch rotor movement was transmitted to a device that stretched spring.
Citizen watch1.jpg

The current watches are usually quartz (called quartzky). Power source is stopwatch timer-wise stepper motor controlled by an electronic circuit. Crystal stopwatch timer determines the piezoelectric quartz crystal (oscillator). Power supply circuit and motor ensures battery (galvanic cell).

Digital stopwatch timer

Digital stopwatch show the time as numbers. On digital stopwatch use two numerical display formats:

    24-hour notation with hours of 00-23;
    12-hour notation with AM / PM indicator, with hours displayed as 12AM, followed by 1AM-11AM, followed by 12PM, followed by 1PM-11PM (notation which is commonly used in the United States).

Due to the need for phone calls or blind people, there are stopwatch that show time sound or spoken language (eg, "Now is exactly twelve hours and thirty five minutes), or acoustic signals (eg, the number of blows ring shows the hours at that point) .

Text stopwatch showing the time in the form of visual language. For example, in English, 12:35 may be displayed as "Twelve thirty-five." Some versions of these watches use a lot closer to measuring, for example, "About twelve-thirty,"
The division according to the stopwatch timing
Mechanical stopwatch mechanism.

The largest number of stopwatch timer is built around some type of oscillator, which changes the position of the endless series of periodic changes, which allow a permanent and stable reference frequency. The periods of this oscillator are counted and converted at a specific time on the stopwatch.

    Mechanical pendulum stopwatch used as an oscillator, which controls the rotation of a series of gears that measure time.

    Crystalline quartz stopwatch use an electronic crystal oscillator and frequency divider or counter. Most crystal watch uses battery-powered oscillator 215 Hz = 32,768 Hz.

    Atomic stopwatch use the microwave oscillator (maser) tuned energy changes of elements such as cesium, rubidium or hydrogen. They are the most accurate stopwatch. The cesium atomic stopwatchs are now used as the official time keepers unit.

    Electric stopwatchs measure periods of 50 or 60 hertz alternating current, whose stable average frequency control specific plant.

    stopwatch Radio periodically activates a built-in radio receiver to automatically adjust the time by radio signal. Radio signals are usually generated by an atomic stopwatch in radio station.

    Sundials use the apparent rotation of the sun around the Earth as your reference oscillation.


A stopwatch in homes and offices, small to wear on your wrist, a large are in public places, eg in railway stations or churches. Small watches are often found in the corner of the computer display or on mobile phones.

The main purpose of the stopwatch is not always to "show" time. He used to "control" or alerts on specific events, such as: alarm stopwatch (alarm stopwatch), sat on the VCR, or a time bomb.

Virtually all computers depend on accurate time signal to be synchronized processes taking place. Some computers also displays the time and date and serve as alarms, triggers certain procedures and events or simply show time.
Navigation

Precise navigation of ships depends on the capability of measuring longitude. Latitude is relatively easy to determine through celestial navigation, but the measurement of longitude requires accurate measurement of time. This was one of the main reasons for the development of accurate mechanical stopwatchs. The first marine chronometer extremely accurate made by John Harrison in the 18th century. "Midday top" in Cape Town still shot gives a precise signal that allows ships to check their chronometer.

Stopwatch countdown timer

Stopwatch (or watch) is an instrument for measuring time. (Usually, the timing intervals less than a day - otherwise the calendar.) Watches that are used for technical purposes, or with extremely high accuracy is sometimes referred to as the chronometer. stopwatch in its most common modern form (in use since the 14th century) the hour (hours), minutes, and seconds and sometimes within 12 or 24 hours.

Replica of ancient Chinese watch with incense sticks
Stopwatch History
A watch is one of the oldest human inventions. In general, it is necessary to know the basic physical processes that recur with some frequency, and a way to measure how long the process takes. As the seasons and the phases of the moon can be used to measure the runoff of certain long periods of time, so the shorter period can be used to measure the hours and minutes. Sundial, which measures the time of day using the directional shadows cast by the object illuminated by the sun, was well known in ancient times. The lamp and incense sticks burning predictable speeds have also been used as stopwatchs. Sand stopwatchs measure the passage of time, fine sand through the narrow opening in the glass container.

Historian Vitruvius reports that the ancient Egyptians used a clepsydra, timing mechanism that runs on water. Historians disagree on the origin of "Antikythera Mechanism" (stopwatchwork found near the Greek island of Antikythera, which is believed to originate from 87th p. N. E.) But it is thought that it was an early mechanical stopwatch. To 9 Ages p. n. email. Mechanical stopwatchs did not have lifts. There is a note that the 1176th Sens Cathedral installed in "Orologi" (words of grkih choir, stopwatch, and legein, speak) - a word that is still used in France for large watches. This word has led scientists to they generate these stopwatchs on the towers did not have hands and dials, but they are "talking" during the acoustic signals such as bells.

The first fairly accurate stopwatchs are stopwatchs on the towers of the 13th century made the monks in Northern Italy (and perhaps they were created). Have been used to publish the "canonical hours" in the intervals between prayer. "Canonical watches" are distinguished by the length of time, and we changed with the changes of sunrise and sunset.

It is believed that the first watch with sound obrojavanjem hours invented Jeong Chang-Sil, the chief engineer of Korea, during the king Džoseona. Dubbed the Chagyongru, which in Korean means "the countdown stopwatch."

The earliest table stopwatchs that survive today as watches from the mid 16 century from metallurgical cities of Nuremberg and Augsburg. These stopwatch had only one hand. Hour meter was divided into four equal parts, so that the stopwatch could tell the time by 15 minutes.
The stopwatch on the Big Ben, London, England. A person 5 feet tall and 4 inches (1.63 m), which shows the label for 6 hours was placed in a life-size image. Hands for long hours of 9 feet (2.7 m) and the minute hand 14 feet (4.3 m)

The next significant development in accuracy occurred in the 1657th with the invention of the pendulum stopwatch. Even before Galileo had the idea to use a pendulum to start flews stopwatchwork. Christiaan Huygens, however, is usually considered to be the inventor. He made a mathematical formula of the length of the pendulum and time (99.38 cm or 39.13 inches for the one second time) and gave the first such watch made. English watchmaker William Clement 1670th made a "funicular railway with an anchor," as opposed to Hajgensovog "lift the crown." In less than a generation have been added, and the minute hand and second.

The excitement for hours with a pendulum attracted the attention of designers who have made various forms of watches. Made the case for placing the pendulum stopwatch. English watchmaker William Clement invented this case the 1670th About the same time the body began to made of wood with a face of glass enamel. Eli Terry's 17th November 1797th patented the first hour. He is known as the founder of the American watch industry.

The development of electronics in the 20th century led to stopwatchs with no stopwatchwork. Time on these online stopwatch is measured in various ways, for example by means of quartz crystal or decay of radioactive elements. Even mechanical stopwatchs powered batteries, which is a winding stopwatch was made redundant.
Types

Stopwatchs can be classified by the manner in which displays the time and in the way they measure time.
The division according to the stopwatch showing time
Analog stopwatchs