In [1]:

```
import math
Vc=3500 #voltage rating of circuit
Vt=750 #voltage rating of each thyristor
Ic=1500 #current rating of circuit
It=500 #current rating of each thyristor
DF=0.1 #Derating factor of circuit
Ns=Vc/(Vt*(1-DF)) #number of devices in series
Ns=round(Ns,0)
print 'Number of Devices in Series=',Ns
Np=Ic/(It*(1-DF)) #number of devices in parallel
Np=round(Np,0)
print 'Number of Devices in Parallel=',Np
```

In [2]:

```
import math
Ed=20.0 #permissible difference in voltage across devices in Volts
Id=1*10**-3 #maximum difference in latching current across devices in Amperes
Qd=10.0 #difference in recovery charge in Micro coloumbs
Vd=20.0 #permissible difference in blocking voltage in Volts
R=Ed/Id #equivalent resistance in Ohms
R1=R
print 'value of equivalent resistance=R=',R1,'ohms'
C1=Qd/Vd #equivalent capacitance in Micro farads
print 'value of equivalent capacitance=C1=',C1,'microfarads'
```