Electrical Circuitry: Converters stabilize the current's varying frequencies. Transformers boost voltage from 690 volts to more than 22,000, so current travels efficiently over long-distance lines.

Electrical Circuitry: Converters stabilize the current's varying frequencies. Transformers boost voltage from 690 volts to more than 22, 000, so current travels efficiently over long-distance lines.

By varying the current to either solenoid, the amount of spool movement can be varied and hence the amount of flow through the valve can be controlled.