Comparison between a RL and RLE circuit ; the current is essentially the same except for the fact that in RLE charge the energy stored in the inductor (which is the same as in the RL circuit) must be discharged in a larger voltage (source + resistor + back emf) which leads to a shorter current. Increasing the inductance leads to a decrease of the voltage below zero, this is due to the fact that the inductor stores more energy therefore on the inversion of the voltage of the source this inductor starts to discharge it's energy in a way that a current still flow in the direction previous to the inversion of the source's voltage leading to a forward biasing of the diode until that energy is completely discharged. The addition of the free-wheeling diode makes the energy of the inductor be discharged in a larger time since de voltage which this energy is discharged is less than the case without the FWD .
