(Last Change: 18.1.03)


Base Circuits and Calculators for the LED Blinker

Circuit without Diode

This version is the Standard Version, but hasn't as much flexibility as other version as THigh is always higher as TLow.

R1 (K Ohms)
R2 (K Ohms)
C (Microfarads)
THigh (msec)
TLow (msec)
f (khz)
T (msec)
Positive Time Interval THigh = 0.693 * (R1+R2) * C
Negative Time Interval TLow = 0.693 * R2 * C
Frequenz f = 1.44 / ( (R1+R2+R2) * C)

Circuit with Diode

This version is my prefered Version as it provides much more flexibility. The Ratio THigh to TLow is the same as the Ratio R1 to R2. It is easy to get shorter THigh than TLow or vice versa by just choosing the correct R1 and R2.

R1 (K Ohms)
R2 (K Ohms)
C (Microfarads)
THigh (msec)
TLow (msec)
f (khz)
T (msec)
Positive Time Interval THigh = 0.693 * R1 * C
Negative Time Interval TLow = 0.693 * R2 * C
Frequenz f = 1.44 / ( ( R1+R2 ) * C)