555 Impulsegenerator Unsymmetrical Pulses
Generating pulses with the 555 Timer IC and change the frequence with a fariable resistor.
Experiment with IC Timer 555 shows a simple unsymmetrical pulse generator.
Schematic schows an asymmetrical pulse generator.
For R117=R116 you can use:
f = 1/( 2.1 * C212 * R217)
For detail signal pulse pause differentiation use:
f=1/(timpulse + tpause)= 1/( ti + tp )
ti= 0.7 * C212 * R217+R216
tp=0.7 * C212 * R216
Detailed calculation for schematic example:
f = 1/ (0.7 * C212(R217+2R216))= 1/ (0.7 10nF(33k+66k)= 1/0.462 sec =1443 Hz
Created on December 28, 2010, 15:45