A system for electronically actuating valves in an engine. The system includes
a first voltage source, a second voltage source, and plural valve actuator subsystems
coupled between the first voltage source and the second voltage source. Each valve
actuator subsystem has a valve actuator and a switch. One of the actuator subsystems
is configured so that current flows from the first voltage source through the valve
actuator of the subsystem when the switch is in a first position, and when the
switch is in a second position, current is permitted to flow from the valve actuator
toward the second voltage source. Another of the valve actuator subsystems is configured
so that current flows from the second voltage source through the valve actuator
of the subsystem when the switch is in a first position, and when the switch is
in a second position, current is permitted to flow from the valve actuator toward
the first voltage source.