Digital timers are used to keep track of many things, such as how long an apple pie needs to stay in the oven or how much time a student has to answer the questions on a test. The earliest timer was an hourglass but when we think about these devices what is likely to come to mind is the mechanical one that was as much a part of the kitchen as the stove or refrigerator (remember that rocket ship pointer?). Mechanical timers are good enough for some things, but tend to be inaccurate and with the advent of inexpensive microprocessor chips there was soon a much better way of counting down to the perfect meal.
Digital timers come in different shapes and sizes and can be combined with a clock to add a bit of convenience as well as functionality. They can also be used for more sophisticated tasks such as turning on and off lights or even kitchen appliances. Some digital timers have 7 day programming capability so that any device that is plugged into it will turn on and off according to the day and time that has been programmed. If you are more interested in a less complicated timer there are plenty that simply count down minutes and seconds. These products can also be rated for either indoor or outdoor use as well as the maximum amperage, so be sure that when you purchase one that it is the correct type for your needs.
The main component of the digital timer is a microprocessor that will provide accurate computation of the time that has elapsed since it was set. There is also a digital display that allows you to see what you have programmed into the timer as well as how much time is left and other important information that you may need to know such as day and time settings. Last but not least are the buttons used for setting the time desired, turning the timer on, and if desired turning it off. The more sophisticated devices also have additional buttons for selecting the day of the week you wish the timer to activate and deactivate.
Digital timers are most commonly found in the kitchen but they are also very useful for turning lights on and off (especially outdoor security and decorative lights).