Apps - SoftwareBasic ElectronicsCircuit AnalysisDigital ElectronicsEE CalculatorsFormulas - Equations

IC 555 Timer Calculator with Formulas and Equations

555 Timer Calculator with Formulas and Equations

IC-555-Timer-Calculator-with-formulas-amp-Equations

Formulas and Equations for 555 Timer IC Calculator

Frequency (f) = 1/ [ ln(2) x C x (R1 + 2R2) ]

Frequency (f) = 1.44 / C x (R1 + 2R2) …. Where… 1/ ln(2) = 1.44

TP = ln(2) x C x (R1 x R2)

TP = 0.693 x C x (R1 x R2) …. Where… ln(2) = 0.693

TN = ln(2) x C x R2)

TN = 0.693 x R2 x C …. Where… ln(2) = 0.693

Where;

  • = Value of Capacitor in Farads
  • R1 and 2R2= Value of the Input Resistance
  • f = Frequency in kHZ
  • TP = Positive or High Time from each pulse
  • TN = Negative or Low Time from each pulse

Enter values and click on calculate. Result will display the calculated quantities. 

Enter your values:
Resistance R1:
Resistance R2:
Capacitance (C): µfarads
 
Positive Time Interval TP: ms (millisecond)
Negative Time Interval TN: ms (millisecond)
Frequency ( f ): kHz (kilo Hertz)

Related Posts and Calculators:

➡️ READ FULL ARTICLE 📖

Electrical Technology

All about Electrical and Electronic Engineering & Technology. Join us on WhatsApp at Electrical Technology Official Channel, to receive the latest content, articles, and updates. You can also like and follow our social media networks below, or subscribe with your email to receive premium engineering articles in your mailbox.

4 Comments

  1. Frankly I think that’s abetulosly good stuff.

  2. Kartik Sikka says:

    I am confused about the value for Tn , that this time required for negative cycle , i think that should be 0.676 *( R1+R2) .
    Can you please share the derivation for it .

  3. Danita Marcum says:

    Kartik, the Tn equation is correct. According to the datasheet for the 555 Timer, astable output, the following formulas are used (this is how the calculator works). Tp = .693 * (Ra + Rb) * C and the Tn = .693 * Rb * C.

    1. Avdhesh Sharma says:

      Specially to A/c distribution
      Kartik in the symentic of log table in power supply and distribution the formula needs of 236vi to 252vi or average 2-3Amp on 2kw. loading in normal consumption or reciprocal in pnp IC Board.this is an average electric charging ac supply. More is available here on request.

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top button

Kindly permit ads on our free website.

It appears that you are using an ad blocker. We rely on advertising to support our website, provide free information, and sustain our services. Kindly consider whitelisting our website to allow ads.