# Title Team Members TA Documents Sponsor
37 Wireless Laptop Charging System
Enrique Ramirez
Jason Kao
Onur Cam
Zhen Qin design_document0.pdf
With the advent of wireless charging products for low-powered devices (phones, tablets etc.), we wonder if we could charge higher powered devices like laptops, by combining them. Laptops in class are very common due to their note taking efficiency. However, economical laptops preferred by students have low battery life, which causes them to rely on their chargers. The prevalence of these laptops causes an excessive amount of cable traffic. We believe that our project will help regulate cable traffic and thus create a more organized classroom.

What makes our project unique is that we are expanding on the concept of wireless inductive charging by connecting multiple low power wireless receiver to create a wireless adapter that plugs in to your laptop's power jack.

Based on our research, there is only one product on the market made by Dell, which retails for $200 and only works with one laptop also produced by Dell. Their laptop has an internal inductive charging receiver, and a transmitter pad.

In our project, we are trading convenience for universality; instead of requiring the purchase of a new laptop for access to wireless charging, you would only need to buy the external adapter and the corresponding transmitter. Our product will target two different markets: academic organizations and individuals. The Qi 1.1 transmitters would be implanted in classroom tables and our receivers will replace the charging blocks.

What we will completely design and build:
4 x Receiver coils
4 x AC to DC Converters -> includes rectifier, filter and regulator circuits.
1 x DC to DC converter-> filter, regulator circuits
1 x Feedback Circuit for DC to DC converter-> includes Error Generator and PI controller

Design thought process:
The charging pad(receiver), will be completely designed by us. It will consist of 4 coils that we will build ourselves.

Our coils will be designed according to the electrical requirements of our AC-DC converter output. The coil should cover at least 75% of the 5W Qi transmitter so that we achieve acceptable efficiency and coupling. By following the WPC(Wireless Power Consortium) standard we will experiment on number of turns and coil dimensions and the gap between them to be able to produce a satisfactory coil that is as small as possible.

Each coil will be connected to its own AC-DC converter. This AC-DC converter will consist a full-wave rectifier, a filter and a regulator to output our goal voltage which is 5V with 5W power. Our 4 AC-DC converters will be serially connected to supply 20V to our self-designed DC-DC converter. This DC-DC converter will step-down the 20V it receives to output 12V and 3.33A DC for powering our laptop.

In order to receive consistent power output from the DC-DC converter, we will implement a feedback system that will regulate the output voltage to the laptop jack. The feedback system will include a error generator, the proportional integral (PI) circuit and a comparator that can change the gate drive input that helps maintain a steady output.

We’ll be powering 4 Qi 1.1 transmitters independently to generate an electromagnetic field for each individual receiver coil, positioned corresponding to our coils in the charger pad. We want our project to be compatible with standard on-the-market transmitters, so we will not be designing the transmitter ourselves.

Our planned design diagram:

Previous rejected RFA:
Idea Discussion:

Product in Market:
Dell Wireless Charging Mat - PM30W17:

S.I.P. (Smart Irrigation Project)

Jackson Lenz, James McMahon

S.I.P. (Smart Irrigation Project)

Featured Project

Jackson Lenz

James McMahon

Our project is to be a reliable, robust, and intelligent irrigation controller for use in areas where reliable weather prediction, water supply, and power supply are not found.

Upon completion of the project, our device will be able to determine the moisture level of the soil, the water level in a water tank, and the temperature, humidity, insolation, and barometric pressure of the environment. It will perform some processing on the observed environmental factors to determine if rain can be expected soon, Comparing this knowledge to the dampness of the soil and the amount of water in reserves will either trigger a command to begin irrigation or maintain a command to not irrigate the fields. This device will allow farmers to make much more efficient use of precious water and also avoid dehydrating crops to death.

In developing nations, power is also of concern because it is not as readily available as power here in the United States. For that reason, our device will incorporate several amp-hours of energy storage in the form of rechargeable, maintenance-free, lead acid batteries. These batteries will charge while power is available from the grid and discharge when power is no longer available. This will allow for uninterrupted control of irrigation. When power is available from the grid, our device will be powered by the grid. At other times, the batteries will supply the required power.

The project is titled S.I.P. because it will reduce water wasted and will be very power efficient (by extremely conservative estimates, able to run for 70 hours without input from the grid), thus sipping on both power and water.

We welcome all questions and comments regarding our project in its current form.

Thank you all very much for you time and consideration!