/*
 * pfn.c -- calc capacitance, voltage, and inductance for a PFN.
 *
 *             compile:   cc -o pfn pfn.c -lm
 *
 *  Copyright (c) 2000, Eddie Kovelan and Sam Goldwasser
 */

#include <stdio.h>
#include <math.h>

main()
{
  float C, L, V, E, T, K;

  printf("\n \
    ************************************************************\n \
    *  This program finds a capacitor (uF), voltage (V),       *\n \
    *  and inductor (uH) for a given energy (J), pulse         *\n \
    *  duration (us), and flashlamp impedance Ko (ohms-A^.5):  *\n \
    ************************************************************\n");

  /* E = 10.0; */      /* Energy (Joules)               */ 
  /* T = 500.0;*/      /* Duration in (us)              */
  /* K =  13.0;*/      /* Lamp Impedance (ohms-A^.5)    */

  printf("\nEnter Energy (J): ");
  scanf("%f", &E);
  printf("Enter Pulse Duration (us): ");
  scanf("%f", &T);
  printf("Enter Lamp Impedance Ko (ohms-A^.5): ");
  scanf("%f", &K);

  C = cbrt( (.09102 * E * ((T * 1e-6) * (T * 1e-6)) / pow(K, 4.0)) ); 
/*  C = cbrt( (.091 * E * ((T * 1e-6) * (T * 1e-6)) /(K*K*K*K)) );*/
  L = (((T * 1e-6) * (T * 1e-6)) / (9 * (C * 1e-6)));
  V = sqrt((2 * E) / C); 

  printf("\n");
  printf("C = %.9f F  -or-  %.3f uF\n", C, C * 1e6);
  printf("V = %.3f volts\n", V);
  printf("L = %.3f uH\n\n", L);
}