Solenoids for mobile sprayers

A mobile sprayer apparatus comprising:

• a direct current electrical supply;
• a supply conduit operative to supply pressurized liquid to a plurality of nozzle assemblies;
• wherein each nozzle assembly comprises:
• a channel connecting the supply conduit to a nozzle;
• a valve operative to selectively open and close the channel;
• a solenoid coil operative to selectively move the valve to an open position when a direct current electrical pulse is connected to pass through the solenoid coil in a first direction, and to selectively move the valve to a closed position when a direct current electrical pulse is connected to pass through the solenoid coil in an opposite second direction;
• a switch connected to the direct current electrical supply and operative to selectively deliver a pulse of electrical energy through each solenoid coil in the first direction or through each solenoid coil in the second opposite direction;
• and
• wherein no electrical energy is delivered to the solenoid coils between pulses.