Difference between revisions of "555 Timer"
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Pin layout for the LM555 timer: [[Image:555_symbol.gif |
Pin layout for the LM555 timer: [[Image:555_symbol.gif]] |
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[http://www.national.com/ds/LM/LM555.pdf Datasheet for the LM555] |
[http://www.national.com/ds/LM/LM555.pdf Datasheet for the LM555] |
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Revision as of 13:22, 3 July 2006
Pin layout for the LM555 timer: File:555 symbol.gif
Inside the 555 timer is a voltage divider the divides +VCC into thirds. A voltage comparator compares the trigger input (pin 2) with 1/3 VCC, and another comparator compares the threshold (pin 6) with 2/3 VCC. The point at 2/3 VCC on the voltage divider is connected to the control voltage.
Monostable and Astable mode
The 555 family of timer chips can be used in either monostable mode or astable' mode.
