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.

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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 28 (Apr. 24, 2019): Final motor selection – Mini-Stepper Motor

Since last week, we have been trying to run the new brushless DC motor; however, it is still difficult to control, let alone its speed. Therefore, we had to pursue our alternative motor, the mini-stepper motor that runs at 5V. Found in Arduino starter kits, this mini-stepper motor is accompanied by its dedicated motor driver board, the ULN2003, which is a chip containing a series of Darlington pair transistors. An image of the stepper motor and the ULN2003 board is shown below: Sources: https://www.adafruit.com/product/858 https://www.amazon.com/gp/product/B01CP18J4A/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1 We were able to successfully run the new mini-stepper motor with the sample code included with the Arduino starter kit. One benefit to using the sample code is that it utilizes the Stepper library’s functions. One use function is the setSpeed( ) function, which allows the user to set the RPM speed of the stepper motor. We found that the ma...

Week 27 (Apr. 17, 2019): ME 195B - Presentation #2 (Prototyping Stage Continuation) Reflection

Today, we completed Presentation 2, which is our 5 th presentation overall, throughout the entire length of senior project, since last semester. Please refer to our Presentation #2 slides, embedded below. Covering the continuation of our prototyping efforts, we discussed progress on hardware acquisition, integration of components into a working circuit, and programming. Regarding programming, we were still working on the communication between the Raspberry Pi and the Arduino. And while the circuit is also coming together, there was one piece that gave us problems yesterday: the gimbal motor broke and so we had to order another motor that is not a gimbal but is still a brushless DC motor. An image of the new motor is found in our presentation slides below. While this was disheartening at first, we found that the gimbal is not intended for continuous rotation, but instead for precise movement, as they are used for cameras on drones. However, this was still a setback...

Patrick Barrera's Progress for Spartan Superway

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