Reed switch pump

A post-mix beverage dispenser comprising:

• a beverage mixing and dispensing nozzle;
• a supply of carbonated water in flow communication with the beverage mixing and dispensing nozzle;
• a supply of beverage syrup;
• and
• a beverage syrup pump and controller system having
• a pump housing having an internal pumping chamber, an inlet port and an outlet port, each of the ports being in flow communication with the pumping chamber, and further having a cylindrical space having an orifice which is also in flow communication with the pumping chamber;
• a pump motor;
• a circuit board having a controller for starting and stopping the pump motor;
• a pumping mechanism driven by the pump motor and at least partially disposed within the pumping chamber, the pumping mechanism being capable of receiving a fluid through the inlet port into the pumping chamber at a first pressure and discharging the fluid from the pumping chamber through the outlet port at a second pressure which is greater than the first pressure;
• a plunger, having a plunger head and a magnet attached to the plunger, movably disposed in the cylindrical space, wherein the plunger head is in contact with a quantity of the fluid at the second pressure so that the fluid exerts a force pushing the plunger into the cylindrical space;
• a spring disposed within the cylindrical space adjacent the plunger which exerts a biasing force pushing the plunger out of the cylindrical space, so that the plunger and the magnet move back and forth along a predetermined path within the cylindrical space as the second pressure increases or decreases;
• and
• a reed switch movable between a first position and a second position and disposed adjacent the path of the plunger magnet, wherein the reed switch moves to a second position when the plunger magnet moves beyond a predetermined point corresponding to the second pressure exceeding a predetermined pressure limit,
• wherein movement of the reed switch to the second position causes the controller to stop the pump motor and movement of the reed switch to the first position causes the controller to start the pump motor.