sawtooth wave oscillatora

The more commonly used Pockels circuit is shown in Figure (c). First, - Vcc
is added to the base of VT2 through Kl, causing VI2 to conduct, and the capacitor C is charged through R. If k is selected, WR is large. Then the charging time is
longer than the discharging time.
    c is quickly charged to the potential The voltage drop of R spit causes the base potential of VTI to become positive through Cl and is cut off.
When c is charging, the collector current gradually decreases, and the power supply voltage passes through the base of the supply and rri, causing VTI to conduct. In this way, the collector voltage of VT1
drops, because the base of VT2 is connected to the collector of VT1 , making \rr2 cut off. Since V12 is turned off, the charge on c is discharged through R until VT2 turns on again when
the emitter potential of VT2 is higher than the base potential . Therefore, periodic sawtooth
waves are generated at both ends of C,