Magnetic switch

In order to switch off magnetic coils we are using the idea of Polzic to compensate the Eddy-current. Zener diode 1N5380B nominal voltage 120 V, maximum voltage 226 V. Problems which we have at this point:

1. spurious current through one of the coils in 'off' regime
2. switching time is too long, due to wrong Zener diode
3. insert switches for two regimes CC (constant current)/ pulsed regime
4. decrease switching time for both up and down voltage change

The scheme of magnetic switch