T=0.69RC=0.69 (Ra+2Rb)C
8 and 4 shorted=> No reset
2 and 6 shorted
Capacitor C from 6 to ground
Ra is connected b/w 8 and 7
Rb is connected b/w 7 and 6
5 capacitor grounded to reduce tipples in dc supply (5V => Vcc)
3 is output
Capacitor charges via Ra and Rb but discharges through Rb only.
So charging cycle T1=0.69 (Ra+Rb) C
Discharging cycle T2= 0.69 Rb C
TIME PERIOD=T= T1+T2= 0.69 (Ra+2Rb)C
Observe that capacitor charges and discharges between (1/3) Vcc and (2/3) Vcc
Ra=1k, Rb=10k, c=0.1uF;
T=1.449mS
f= 690Hz
Ra=10k, Rb=22k, c=0.1uF;
T=
f=
Ra=500, Rb=1k, c=0.1uF;
T=172.5uS
f=5.79KHz
