Timer circuits are used to control sequences of events in electronic systems. They work by changing the circuit from one state to another in advance.
Applications for timer circuits
You can use timer circuits for basic timing functions, like turning a light on for a certain amount of time or creating a flashing light. They can also be used to create musical notes of a particular frequency.
555 timers
The most widespread type of timer circuit is the 555 timer, which is made up of an eight-pin dual in-line package containing 25 transistors, two diodes and 16 resistors. They can be used as either astable or monostable timers:
Monostable: Often called a one-shot timer, a monostable timer stays on for a certain length of time and then turns off. The timing process starts when the timer is switched on.
Astable: An astable timer is switched on to provide a constant on/off digital output. The timer can be used make an LED flash, and the rate of flashing is determined by a capacitor in the circuit.
Description:
Intersil offers the 555 timer, a highly stable
controller capable of producing accurate timing pulses. With monostable operation, you control the time delay by one external resistor and one capacitor. With a stable operation, the frequency and duty cycle are ...
Description:
A range of highly stable precision timing circuits
for the generation of accurate time delays or timing pulses. These timers can be operated in monostable (one-shot) or astable (oscillator) mode with timing periods ranging from less than a microsecond to ...
Description:
ON Semiconductor offers the industry standard 555 timer,
a highly stable controller capable of producing accurate timing pulses. With monostable operation, you control the time delay by one external resistor and one capacitor. With a stable operation, the frequency and ...
Description:
The Watchdog Timer integrated circuit is a self-contained
device for preventing system failures. Certain types of hardware or software errors could cause the electronics system to fail. The watchdog timer has an input that is used to clear the watchdog ...
