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555: Rozdiel medzi revíziami

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(Nová stránka: == Časovač 555 == The oscilating circuit diagram is pretty simple, featuring the 555, and then a couple of resistors & capacitors that define the actual frequency of the oscillat...)
 
d (Časovač 555)
Riadok 1: Riadok 1:
 
 
== Časovač 555 ==
 
== Časovač 555 ==
  
Riadok 18: Riadok 17:
 
C1 is measured in Farads, R1 & R2 are in Ohms, so for values in schematic:
 
C1 is measured in Farads, R1 & R2 are in Ohms, so for values in schematic:
  
T = 0.693 × (100000 + 2×22000) × 0.00001 = 0.99792 seconds (or 1.002 Hz)
+
T = 0,693 × ( 100 000 + 2 × 100 000) × 0.00001 = 0.99792 seconds (or 1.002 Hz)
  
 
If you want a different frequency, you would change the values of C1, R1 & R2. Changing the capicitor is the easiest to imagine -- if you go from a 10 µF capacitor to 1 µF, it will take 1/10 the time to charge, so your frequency will go up by a factor of 10.
 
If you want a different frequency, you would change the values of C1, R1 & R2. Changing the capicitor is the easiest to imagine -- if you go from a 10 µF capacitor to 1 µF, it will take 1/10 the time to charge, so your frequency will go up by a factor of 10.

Verzia zo dňa a času 07:11, 14. október 2010

Časovač 555

The oscilating circuit diagram is pretty simple, featuring the 555, and then a couple of resistors & capacitors that define the actual frequency of the oscillation. Pay attention to the pin numbers.

555oscilator.png


In reality, when you build it out, the circuit should look like this one:

TODO: image


You can calculate frequency using this formula:

T = 0,693 × (R1 + 2×R2) × C1

C1 is measured in Farads, R1 & R2 are in Ohms, so for values in schematic:

T = 0,693 × ( 100 000 + 2 × 100 000) × 0.00001 = 0.99792 seconds (or 1.002 Hz)

If you want a different frequency, you would change the values of C1, R1 & R2. Changing the capicitor is the easiest to imagine -- if you go from a 10 µF capacitor to 1 µF, it will take 1/10 the time to charge, so your frequency will go up by a factor of 10.