Timer circuits are used to control one or more sequences of events within an electronic system. Timer circuits work by changing the circuit from its current state to another in advance following a set parameter.
Where would I use a timer circuit?
You can use timer circuits for a wide range of basic timing functions, like turning a light on for a certain amount of time or on and off repeatedly within a set time to create a flashing light or lighting sequence. Timer circuits 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.
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Texas Instruments range of Counters and Shift Registers
from the 74LS Family of Low Power Schottky Logic ICs. The 74LS Family use bipolar junction technology coupled with Schottky diode clamps to achieve operating speeds equal to the original 74TTL family ...
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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 ...
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Diodes Incorporated 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 ...
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Microchip offers the RC Timers / Oscillators with
similar in function to 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 ...