* Alternating Circuit is a simple L and C lossless oscillating circuit.
*  Modify this so the change in permittivity is what is in a gravity field.
*  Also test Planck's equation to see if energy and frequency track the equation.
*  The code has not been added yet.  9/20/2022

* We will impose a varying permittivity and permeability on the circuit.
* VOLTAGE, CURRENT, ENERGY IN C, ENERGY IN L, TIME IN SECONDS, DELTA TIME STEP
* CAPACITANCE, INDUCTANCE, DELTA V, DELTA V OLD, PERIOD OF ONE AC SWING, ENERGY, CURRENT MAX
      REAL*8 V,I,IM,EC,EC0,EL,T,DT,C,L,DV,DVO,TP,E,DL,DC
      PRINT *,'AN LC CIRCUIT IS LOWERED TO A LOWER GRAVITY POTENTIAL'
      PRINT *,'ENTER DELTA L AND DELTA C MULTIPLIERS TO SEE THE EFFECT'
      PRINT *,'WE ARE TESTING TO SEE IF GRAVITY IS MORE CONSISTENT WITH'
      PRINT *,'PERMITTIVITY OR PERMITTIVITY CHANGING.'
      V=1.
      T=0.
      DT=.0001
      C=1.
*      DC=1.000001         ! LET THE CAPACITANCE SLOWLY INCREASE AS WE ENTER A HIGHER PERMITTIVITY REGION
      WRITE(*,*)'ENTER DC MULTIPLIER, 1 IS NO CHANGE, 1.00001 SLOW INCR'
      READ *,DC
      L=.01
      WRITE(*,*)'ENTER DL MULTIPLIER, 1 IS NO CHANGE, 1.00001 SLOW INCR'
      READ *,DL
      I=0.
      TP=0.
      DVO=0.             ! START OUT AS NEITHER INCREASING NOR DECREASING
      DV=0.
      IM=0.
      WRITE(*,*)'     V         C        EC         I        EL       ',
     &'SEC        HZ'
    1 DVO=DV
      I=I+V*DT/L
      IF(ABS(I).GT.IM) THEN
        IM=DABS(I)
        EL=.5*L*IM**2
      ENDIF
      EC=.5*C*V*V
      IF(T.LE.0.) WRITE(*,'(10F10.6)') V,C,EC,IM,EL
      DV=-I*DT/C
      V=V+DV
      T=T+DT
      IF(DVO.GT.0..AND.DV.LT.0..AND.TP.LE.0.) TP=T  ! CAPTURE THE FIRST AC WAVE PERIOD
      IF(TP.LE.0.) GOTO 1
      WRITE(*,'(10F10.6)') V,C,EC,IM,EL,T,1/TP
      EC0=EC      ! remember the initial energy in the capacitor
      F0=1/TP     ! remenber the initial frequency
      TP=0.
      T=0.
    2 DVO=DV
      L=L*DL
      C=C*DC      ! WE LET THE CAPACITANCE CHANGE A SMALL AMOUNT
      V=V/DC      ! TO HOLD CHARGE CONSTANT AS THE CAPACITANCE CHANGES OVER THE TIME STEP
      I=I+V*DT/L
      IF(ABS(I).GT.IM) THEN
        IM=DABS(I)
        EL=.5*L*IM**2
      ENDIF
      EC=.5*C*V*V
      DV=-I*DT/C
      V=V+DV
      T=T+DT
      IF(DVO.GT.0..AND.DV.LT.0..AND.TP.LE.0.) TP=T  ! CAPTURE THE FIRST AC WAVE PERIOD
      IF(TP.LE.0.) GOTO 2
      WRITE(*,'(10F10.6)') V,C,EC,IM,EL,T,1/TP
      IF(1/TP.GE.1.) THEN
        T=0.
        TP=0.
        IM=0.
        GOTO 2
      ENDIF
      PRINT *,'RATIOS OF ENERGY CHANGE AND FREQUENCY CHANGE'
      WRITE(*,'(19H ENERGY RATIO     =,F20.6)') EC0/EC
      WRITE(*,'(19H FREQUENCY RATIO  =,F20.6)') F0/(1/TP)
      WRITE(*,'(19H ENERGY/FREQUENCY =,F20.6)') (EC0/EC)/(F0/(1/TP))
      STOP
      END