A thyristor can be fired with dv/dt of 200 V/microsecond. If the forward breakover current of the device is 5 mA...
Thyristor dv/dt Capacitance Calculation
Given Data
- dv/dt = 200 V/Ξs = 200 × 106 V/s
- Forward breakover current I = 5 mA = 5 × 10-3 A
Key Formula
I = C (dV/dt)
Step: Solve for Capacitance
C = I / (dV/dt)
Substitute Values
C = (5 × 10-3) / (200 × 106)
Calculation
C = (5 / 200) × 10-9
C = 0.025 × 10-9
C = 2.5 × 10-11 F
Final Answer
C = 25 pF
option A
option A
- This represents the effective junction/diffusion capacitance
- High dv/dt can generate current large enough to trigger the thyristor
- Snubber circuits (RC) are used to limit dv/dt
- This prevents false triggering of thyristors