Small Scale Controls Team

Since last week, the team has 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 we were 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 we don’t want to charge the LiP...

Our Presentation #1 has been moved from next week – Wednesday, February 27, 2019 – to the following week – Wednesday, March 6, 2019, granting us a reprieve and permitting us more time to get more work done before the presentations. We have been working on several things this past week. David has been working on the Serial communication between the XBee on the Raspberry Pi and the XBee on the Arduino in the pod car. Specifically, he has been working on: acquiring a real-time location of each pod car, determining the distance between the passenger pick-up location and the closest pod car, and determining the distance between the passenger pick-up location and the passenger drop-off location. This past week, Patrick has been working on getting the Electronic Speed Controller (ESC) to run the gimbal. Additionally, he has been working on a barebone circuit, consisting of the induction charger, the LiPo battery charger, and the 3.7V LiPo battery, and the motor. However, using th...