Pulsars manufactures model pmv 5100 micro-controller based beverage dispensing machine which has a user-friendly time setting method. The beverage dispensing machine senses the water levels in the boiler and tank by means of conductive probes and the valves are opened accordingly., the sensing is done for such short durations at appropriate times by a special time splice method so that rusting of probes is avoided. To power 12 v dc valves a high power dc power supply board is provided along with this unit. This bevarage dispensing machine comes with 4 relays among which two are for powder motors and two for whipper motors, 3 transistors with two for water valves and one for constant head valve. The unique oeration of the bevarage dispensing machine starts when the ready led glows and pressed the two leds for coffee and tea glow and the ready led goes off. The constant head valve is opened after checking the level sensors during this time. When coffee or tea is selected by pressing corresponding switch, following events happen. Led of the selected drink glows whereas the other led is off. Corresponding water valve and powder motor operate for set times. Constant head valve opens when the second level sensor is out of water. When the water covers the top level sensor in the boiler, chv is closed. Ready led is on and the bevarage dispensing machine is ready for next cycle. These bevarage dispensing machine comes with an advantage of whenever the water level in the boiler goes below the third level sensor, the microprocessor detects it and switches off the heater relay thereby avoiding damage to the heater coil.
