Equipment for the generation of stabilized high direct voltage, particularly for use in combination with a non-polluting muffler

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT With reference initially to the block diagram in FIG.
1, 1 indicates schematically a DC/DC converter at whose input there is present the low voltage Vin, for example the voltage supplied from the alternator of the vehicle in which the equipment is installed.
At the output of the DC/DC converter (which, like the other functional blocks in FIG.
1, will be described in greater detail with reference to the circuit diagram in FIGS.
2A, 2B, 2C and 2D) there is a direct voltage of approximately 160V, which is applied to the primary of a step-up transformer 2.
The voltage applied to the terminals of the primary of the transformer 2 is divided by the closing and opening of a switch 11 constructed with a MOSFET transistor which is alternately caused to conduct and to cut off in the way described below.
During the time interval in which the transistor 11 is conducting, the direct voltage of approximately 160V leaving the DC/DC converter 1 is present at the terminals of the primary winding of the transformer 2.
Conversely, during the cut-off interval of the transistor 11 a quasisinusoidal halfwave produced by an L/C circuit consisting of the primary inductance and the dispersed inductance of the transformer 2 and the parasitic capacitance of the windings of said transformer is present at the terminals of the primary of the transformer 2.
The subsequent halfwaves form voltage peaks which are used as described below to generate the high output voltage of the equipment.
By suitably controlling the transistor 11, these voltage peaks are delayed in such a way that the output voltage is substantially constant with the variation of the load applied to the high-tension terminal (Vout).
More particularly, the interval between one peak and the next is determined from time to time as a function of any discrepancy between the high output voltage of the equipment and a preset voltage value.
The conducting interval is selected in such a way that during this time an energy as great as the difference between the real voltage and the desired voltage may be accumulated in the transformer 2, so that in the subsequent cut-off interval of the transistor 11 sufficient energy is transferred to the secondary of the transformer 2 to overcome the difference between the actual voltage and the required voltage