Order a Pcb

Custom Printed Circuit Boards (PCBs)

Please refer this PCB checklist : PCB Checklist FA25.pdf

How to check your gerber file : PCBway_gerber_file_check_FA25.pdf

How to use the PCB oven (2070 ECEB) : Using the PCB Oven

In this course, you will be creating and ordering a PCB to use in your project. The primary method for ordering PCBs is to order them through PCBWay. With the help of your TA, you can order a simple, 2-layer, 100mm x 100mm PCB through PCBWay at no cost to you. This PCB will simply be fabricated, as opposed to assembled, so a major portion of this class will be soldering and assembling the PCB you order. This means that you will need to source your components either through the course or other means. See the getting parts page for more details.

Alternatively, you can order a PCB from any outside vendor (including PCBWay) and pay for the cost of the board out of pocket. By paying for a PCB yourself, you are not required to meet the deadlines imposed by the course and can sometimes get your board more quickly.

In rare cases, some teams will be allowed to order PCBs through the Electronics Services Shop in ECEB. If you have need of special board layouts or require a PCB very early in the semester, please discuss this option with your TA as early as possible.

PCBway Orders Through the Course

Orders through PCBway can be submitted and paid for by the ECE department with the help of your TA. Orders will be uploaded to PCBway by your TA and paid for on the dates listed on the course calendar. Please note that the PCBway orders will not be manufactured or shipped until they are paid for so please be aware of the lag time between order submission and payment. In addition, your order must pass PCBway's audit before the payment date for your order to be processed. In order to help students pass audit more quickly, we have provided a DRC file that can be imported in to EagleCAD to verify that your board meets PCBway's capabilities. Passing the DRC does not guarantee that your board will pass audit but it does greatly increase the probability of that event.

Electronic Services Shop

Orders placed through the Electronic Services Shop will require TA approval so please discuss with your TA before contacting the Services Shop. The software most commonly used is EagleCAD. Contact a technician in the Electronic Services Shop with questions.

Please be aware of the PCB deadlines posted on the course calendar. If you are unable to meet these deadlines, you will not be able to order a PCB through the the Electronic Services Shop. You will still be able to order PCBs through third party vendors, just be aware that rushed orders can become expensive.

Commercial quality boards

The most commonly used programs for board layout are Eagle and Orcad Layout. The two software packages below allow a schematic to be drawn and translated into a board layout.

Once the board has been laid out, some companies will manufacture small quantities for a very reasonable price.

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.