Week 25 (Apr. 3, 2019): Current Amplification Solved via Buck Converter

Today, we made the decision of going with the 12V, 600mA induction coil set, as they allowed for a greater distance between the transmitter and receiver, which was a maximum distance of 0.787 inches, as opposed to the 5V, 1500mA induction coil set, which had a maximum charge distance of 0.5 inches.

As a reminder, we are implementing induction charging, also known as wireless charging, to charge the 3.7V Li-ion battery at designated charging stations within the track. This helps to enforce autonomy, which will further eliminate human intervention and manual maintenance of the system.

Because the charge current is smaller, we tried to find a way to increase the charge current used to charge the battery. We settled upon using a buck converter, which decreases voltage with the advantage of increasing current. The buck converter would be placed after the induction receiver and before the battery charger. After some testing, we found that the buck converter could amplify the current to the desired 1A. However, since the battery charger has a maximum charge current of 1A, we decided to lower the charge current to a safer 800mA.

An image of the buck converter is shown below, as well as the Amazon purchase link with all of the product details:

Source: https://www.amazon.com/gp/product/B07JNQFV7F/ref=ppx_yo_dt_b_asin_title_o01_s01?ie=UTF8&psc=1

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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 20 (Feb. 27, 2019): Power Electronics – Battery & Amplifier

Since last week, I have been working on the current amplifier for the induction charger. We decided to abandon using the TPS53313 step down voltage regulator-current amplifier IC (rated at a maximum of 6A continuous output current) because we found that supplying +5V to a 3.7V LiPo battery was possible and safe. Additionally, charging a LiPo battery at 6A was found to be dangerous; the battery should be charged at 25% of the capacity rating (.25 x C), or .25 x mAh. In the case of the 6600mAh battery, it should be recharged at a rate of 1.65A or less. The last reason is that dealing with a surface mount device (SMT) is a bit difficult. I started out using a BJT NPN transistor (model: 2N3904), something I was most familiar with. However, its datasheet states that it has a 200 mA maximum continuous collector current rating. This is a significantly low current. Most, if not all, fast charging adapters today have a 2 A charging rate. While I don’t want to charge the LiPo batteri...

Week 0 (Aug. 23, 2018): Beginning Spartan Superway

Hello, and welcome to my Spartan Superway blog! My name is Patrick Barrera, and I am a senior mechanical engineering student with a focus in mechatronics. Once I graduate, I hope to go into at least one of my areas of interest: electronics, programming, biotechnology, and machine learning. Some of my hobbies include staying in shape by working out and biking, doing DIY electronic and coding projects, and spending time with my family. Working on the Spartan Superway project interests me because I would like to be a part of the future ... the future of transportation, the future of technology, and the future of society. I like working in interdisciplinary teams, especially with focuses in mechanical design as well as mechatronics, because I am able to learn things from outside my areas of knowledge. I would also like to expand my knowledge and skill set into areas that I do not know, such as welding and other machine tools, and to get hands-on experience with the concepts I learned fro...

Patrick Barrera's Progress for Spartan Superway

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