# Title Team Members TA Documents Sponsor
18 Refill Dispensary
Jackson Wiessing
Lyla Zegelstein
Michael Blyakhman
Jason Paximadas design_document2.pdf
# Refill Dispensary

By: Micheal Blyakhman (mlb11), Jackson Wiessing (jtw6), Lyla Zegelstein (lrz2)

## Problem Description:
Plastic waste happens all over the United States. It’s problematic because plastics don’t decompose and end up in landfills or waterways. There have been traces of plastics found in fish. The environment would benefit greatly if there was a shift away from plastic and instead towards more reusable bottles. We will target the single-use plastic crisis by designing a refill station where a customer can bring their own containers or bottle and refill it.

## Competitors:
Many refill stations already exist which provides concept validation. One competitor is Henkel that has both makeup and laundry detergent refill stations in Europe. The makeup refill is simply a bottle with a pump where users are expected to dispense their own product. One potential issue is expecting users to be honest about the amount they take and not spill any of the product. Henkel’s laundry detergent refill station operates similar to a soda machine where each type of product has its own dispenser. These machines are very large and only offer laundry detergent.

We would like to innovate on this concept by designing a machine where multiple types of unrelated products can be offered to customers. The competitive advantage is being able to tailor the machine to different areas. One neighborhood might buy lots of quinoa, shampoo, and cereal, but another one may demand laundry detergent, rice, and ketchup. Different types of goods should all be able to be stored in the same machine and fit the demand of an area.

## Solution Overview:
Our design is highly scalable and customizable. By creating 3 types of dispensing methods that take up the same amount of space in the machine, we are laying the foundation for future machines to hold any combination of the types of dispensing methods. Furthermore, more types of dispensers can be added to the machine for more specialized items(e.g. eggs).

## Solution Components:
The machine will consist of 6 main parts: item storage, dispensing method, cap chooser, dispensing hole, container spot, user interface.

- Item storage - we will have a round circular holder. In this holder, items to be dispensed will be held in a container. For our demo, we will probably use bottles and load them into a 3D printed part. The item storage will be attached to a motor that spins the holder circularly until it gets the selected item in a spot directly above the dispensing hole.

- Dispensing Method - The method used will depend on the type of item that needs to be dispensed and will live inside of the holder for this machine. Here is what this might look like for our project.
A bottle that has a plunger inside that will push liquids of varying viscosities out.
A catchment system that dispenses items 1 at a time (ex: roll of toilet paper, single tide pod).
A measurement system for dispensing precise quantities of items that would come out fast (ex: rice).

- Cap chooser - for contamination purposes each item that gets dispensed, will have its own protective layer over the dispensing hole.

- Dispensing hole - the area in which an item is passed outside of the machine

- Container spot - the area where a user places their own container. This should feature some system for ensuring that the container is present.

- User interface - method for a user to select a quantity and item. Most likely a screen with physical buttons.

## Criterion For Success:
A 100% successful product would complete this story from beginning to end with no issues.

1. Machine gets stocked
2. User goes to the machine and selects the blue item.
3. Item storage spins until the blue item is above the dispensing hole
4. Cap chooser moves left/right to get the proper cap over the hole
5. Cap chooser inserts the cap into the hole
6. Item storage lowers the blue item bottle into the cap
7. Item gets dispensed
8. User takes their newly filled container

Active Cell Balancing for Solar Vehicle Battery Pack

Tara D'Souza, John Han, Rohan Kamatar

Featured Project

# Problem

Illini Solar Car (ISC) utilizes lithium ion battery packs with 28 series modules of 15 parallel cells each. In order to ensure safe operation, each battery cell must remain in its safe voltage operating range (2.5 - 4.2 V). Currently, all modules charge and discharge simultaneously. If any single module reaches 4.2V while charging, or 2.5V while discharging, the car must stop charging or discharging, respectively. During normal use, it is natural for the modules to become unbalanced. As the pack grows more unbalanced, the capacity of the entire battery pack decreases as it can only charge and discharge to the range of the lowest capacity module. An actively balanced battery box would ensure that we utilize all possible charge during the race, up to 5% more charge based on previous calculations.

# Solution Overview

We will implement active balancing which will redistribute charge in order to fully utilize the capacity of every module. This system will be verified within a test battery box so that it can be incorporated into future solar vehicles.

Solution Components:

- Test Battery Box (Hardware): The test battery box provides an interface to test new battery management circuitry and active balancing.

- Battery Sensors (Hardware): The current battery sensors for ISC do not include hardware necessary for active balancing. The revised PCB will include the active balancing components proposed below while also including voltage and temperature sensing for each cell.

- Active Balancing Circuit (Hardware): The active balancing circuit includes a switching regulator IC, transformers, and the cell voltage monitors.

- BMS Test firmware (Software): The Battery Management System requires new firmware to control and test active balancing.

# Criterion for Success

- Charge can be redistributed from one module to another during discharge and charge, to be demonstrated by collected data of cell voltages over time.

- BMS can control balancing.

- The battery pack should always be kept within safe operating conditions.

- Test battery box provides a safe and usable platform for future tests.