Power reserve
Encyclopedia
Power Reserve Indicator (originally called ) is a complication
of the watch
, which is designed to show the amount of remaining stored energy. The power reserve indicator indicates the tension on the mainspring
at any particular moment.
besides the actual time
display. The mechanical watch operated either by automatic- or manual winding. In order to run at a regular rate a mechanical timepiece needs to have at least 30 per cent of its mainspring wound. An automatic timepiece needs to be worn for about 10–15 hours before it is fully wound.
The power reserve indicator displayed on the watch with automatic- winding movement shows how long a watch will function when not worn. The one displayed at a watch with the manual winding mechanism shows the time left for its next winding.
s and later in the accurate Railroad grade pocket watches. Today they are used in wrist watches. The first wristwatch with the mechanism was created by Breguet
in 1933. However this was only a prototype with only one watch assembled.
In 1948, Jaeger-LeCoultre
introduced a power reserve indicator designed for production in a series of watches called the Powermatic which utilized the LeCoultre Caliber 481. Thus Jaeger-LeCoultre was ostensibly the first watchmaking company to launch wristwatches with a power reserve indicator to the masses.
Complication (horology)
In horology , complication refers to any feature in a timepiece beyond the simple display of hours, minutes, and seconds.A timepiece indicating only hours, minutes, and seconds is otherwise known as a simple movement...
of the watch
Watch
A watch is a small timepiece, typically worn either on the wrist or attached on a chain and carried in a pocket, with wristwatches being the most common type of watch used today. They evolved in the 17th century from spring powered clocks, which appeared in the 15th century. The first watches were...
, which is designed to show the amount of remaining stored energy. The power reserve indicator indicates the tension on the mainspring
Mainspring
A mainspring is a spiral torsion spring of metal ribbon that is the power source in mechanical watches and some clocks. Winding the timepiece, by turning a knob or key, stores energy in the mainspring by twisting the spiral tighter. The force of the mainspring then turns the clock's wheels as it...
at any particular moment.
Overview
The power reserve indicator is one of the most useful features of a mechanical watchMechanical watch
A mechanical watch is a watch that uses a mechanical mechanism to measure the passage of time, as opposed to modern quartz watches which function electronically. It is driven by a spring which must be wound periodically...
besides the actual time
Time
Time is a part of the measuring system used to sequence events, to compare the durations of events and the intervals between them, and to quantify rates of change such as the motions of objects....
display. The mechanical watch operated either by automatic- or manual winding. In order to run at a regular rate a mechanical timepiece needs to have at least 30 per cent of its mainspring wound. An automatic timepiece needs to be worn for about 10–15 hours before it is fully wound.
The power reserve indicator displayed on the watch with automatic- winding movement shows how long a watch will function when not worn. The one displayed at a watch with the manual winding mechanism shows the time left for its next winding.
Brief history
There are numerous devices for recording the amount of mainspring power stored in the barrel. Power reserve indicators were employed very early on marine chronometerMarine chronometer
A marine chronometer is a clock that is precise and accurate enough to be used as a portable time standard; it can therefore be used to determine longitude by means of celestial navigation...
s and later in the accurate Railroad grade pocket watches. Today they are used in wrist watches. The first wristwatch with the mechanism was created by Breguet
Breguet
Breguet may refer to: * Breguet , watch manufacturer* Breguet Aviation, a defunct French aircraft manufacturer; was formally known as "Société Anonyme des Ateliers d'Aviation Louis Breguet"...
in 1933. However this was only a prototype with only one watch assembled.
In 1948, Jaeger-LeCoultre
Jaeger-LeCoultre
Jaeger-LeCoultre is a high-end luxury watch and clock manufacturer based in Le Sentier, Vaud, Switzerland. In addition, Jaeger-LeCoultre also has a long tradition of supplying movements and parts to other prestigious watch companies in Switzerland. Since 1996, Jaeger-LeCoultre has been a fully...
introduced a power reserve indicator designed for production in a series of watches called the Powermatic which utilized the LeCoultre Caliber 481. Thus Jaeger-LeCoultre was ostensibly the first watchmaking company to launch wristwatches with a power reserve indicator to the masses.