Week 12 (Nov. 14, 2018): Regulator-Amplifier IC (Integrated Chip) Selection

Today, I explained to Dan, one of the coaches, that I narrowed my search for an induction charger module (consisting of a transmitter and receiver) to two possibilities: 12V at 600 mA, or 5V at 2 A. In the case of the former (12V, 500mA), we must buck down (step down) the voltage to around 7.4V, the battery voltage, and increase the current to at least 1.5A to achieve a decent charging rate (“fast-charging” cell phone adapters are rated at 2.1A). In the case of the latter (5V, 2A), we must simply boost up (step up) the voltage to around 7.4V, the battery voltage.

Dan recommended buying the 12V at 600mA induction charging module, and then getting an IC (Integrated Chip, which is basically an electronic chip containing a very tiny circuit) that will step down the voltage to around 7.4V, and another IC that will amplify current to 1.5A. He also said that there are chips that can do both regulate voltage and amplify current. He suggested sites, such as Texas Instruments (TI) and Analog Devices.

Following Dan’s advice, I began looking into TI’s repository of IC’s. I was eventually able to find an IC that indeed does both regulate voltage and amplify current! 2 for the price of 1! Thanks to TI’s Component Parametric Comparison Tool, we selected the “TPS53313 6-A Step-Down Regulator With Integrated Switcher”. The notable features of this chip are as follows: a 4.5V to 16 V input voltage range, an adjustable output voltage ranging from 0.6V to 70% of the input voltage, and a continuous 6A output current or a selectable 5A, 6A, or 9A peak output current. With this chip, we can step down the voltage from 12V to a maximum of 8.4V (70% of 12V) and amplify the current from 600mA to a maximum of 9A! Therefore, this chip will be connected between the induction charger receiver and the LiPo battery charger. The portion of the datasheet containing this information is shown below.

I also ordered both types of induction chargers (12V, 600mA and 5V, 2A), just in case the former would not work. However, we will try out the 12V, 600mA charger first.

UPDATE: Calculations for the induction charging and battery are found in the Week 14 and Week 15 blog posts.

Comments

Week 29 (May 1, 2019): CAD of Induction Charger Hub & Podcar Door, then 3D Printing

This week, while David worked on the Raspberry Pi and the Arduino code, Patrick completed the CAD (computer-aided-design) models. We had to create 3D solid modeling of two parts: the induction charging hub to hold the induction transmitter coil and the pod car door to hold the induction receiver coil. Over the weeks, the CAD models underwent several revisions. The induction hub saw two revisions, with the third design being the final version. Because the 3D printer available to us in the shop, the Prusa Mark3 i2, had a bed length of 10 inches, we had to restrict the length of the charging hub to a safe 9.5 inches. Version 1 simply entailed us placing the hub on the side of the bracket and then screwing it into place on the bracket’s side via the two holes at the top: For version 2, in addition to placing the hub on the side of the bracket and then screwing it into place on the bracket’s side via the two holes at the top, the bracket would wrap around the two bracket...

Week 30 (May 8, 2019): Prototype Evaluation Day, Final Circuit, Incorporating 3D printed parts, Final Presentation, Posters, & Maker Faire

Today, we held Prototype Evaluation Day. Like the rest of the senior project classes, the advisor walks around the classroom, evaluating the senior project apparatuses, asking the student teams to demonstrate their devices, and explain their design, though processes, and results. Dr. Furman and Ron examined and inspected the Full-Scale model, then the Half-Scale model, and lastly, us, the Small-Scale Team. We had completed our circuit to power one pod car and one of the two induction charging stations prior to Evaluation Day, so we were able to successfully demonstrate the pod car driving around the track as well as the induction charging. While we were still troubleshooting issues with the tablet’s Raspberry Pi communicating with the Arduino, the Arduino is still capable of operating on its own, so we could at least demonstrate the motor driving the pod car around the track and through the offline stations. Depicted below is our final circuit that powers the pod car: Dep...

Week 26 (Apr. 10, 2019): Programming – Python and Arduino Communication

The Python code and the Arduino code are able to run successfully on their respective boards, i.e. the Raspberry Pi in the tablet and the Arduino in the pod car. However, the Raspberry Pi is having issues sending data to the Arduino via the XBee RF (radio-frequency) module, specifically the user-input data. Whenever the user inputs the pickup station, destination, and selects a pod car, the Serial Monitor on the Arduino IDE does not show any of the data. Investigating further, we plugged the XBee module into one of our laptops, then opened the XCTU software’s (the software which deals with RF modules) Serial port as well. Now, whenever the user inputs the stations, we can see on the XCTU Serial Monitor that the receiving XBee does get the pickup station, destination, and pod car number, but the three inputs are all found between jumbles of random characters. As displayed in the screenshot of the XCTU software below, if the user inputs pickup station 2, destination station 5, and sele...

Patrick Barrera's Progress for Spartan Superway

Search This Blog