Current limiter component

A current limiter comprising;

• a semiconductor bar including an anode for input of a current to be limited and a cathode for output of the current, said semiconductor bar successively including between said anode and cathode, a first layer doped P at greater than 10.sup.18 atoms/cm.sup.-3 with a depth of diffusion between approximately 0.5 and 5 microns, a second layer doped N at less than 10.sup.15 atoms/cm.sup.-3 and a diffusion depth of between approximately 5 to 90 microns, a third layer doped P at between 10.sup.17 and 10.sup.19 atoms/cm.sup.-3 and a diffusion depth of between approximately 5 to 90 microns, and a fourth and last layer doped N at greater than 10.sup.18 atoms/cm.sup.-3 and a diffusion depth of between approximately 0.2 to 2 microns, a first junction defined between said first and second layers, a second junction defined between said second and third layers and a third junction defined between said third and fourth layers, said first, second, third and fourth layers being doped and said semiconductor bar having dimensional characteristics such that a current-voltage graph characteristic of the current limiter is like that of a diode reflecting increase in both voltage values and current values for current values up to a current limiting value and, above the current limiting value, a graph characteristic of a plateau reflecting that the current value remains substantially constant until voltage increases to a breakdown voltage value.