Circuit Design and Valve Placement
The drink elements will flow when their corresponding valve is opened, so I designed a circuit capable of switching power for each solenoid valve. The AutoBart will be a modular system, starting with the capacity for 12 drink elements, but having the option of expanding to 24, or 36.
The signal lines are isolated from the external 24V power supply through an opto-isolator, the FETs will be fuse protected and capable of ~1A, and each channel has an LED indicator. The screw terminals and DB15 connector are arranged like the CB15 Terminal Board, so it will be compatible with any LabJack. The next step will be to solder in components and write software.
While the power switch board is being printed I started with valve placement and design. The circular arrangement of valves will allow direct flow from the output of the valve into a mixing funnel. I used some drafting tools to make a template, and a center punch to indicate where to drill the mounting holes.
After I find some more 1/8" NPT barbed adapters, it will be time to make another layer of 12 valves and a mounting stand.