The goal of Let the Power Go to Your Head (LPH) is to give extra battery life to electronic devices such as phones, cameras, and other portable devices that are used in an outdoor environment. A critical aspect of the project is that this will be accomplished using a renewable energy source, so there is no need to use an outlet to extend battery life. The final product will be compatible with the majority of common small electronic devices. LPH focuses on developing a helmet-mounted charger that will connect to a GoPro camera, but other applications are possible.
Proof of Concept
Team 29 does not yet have an assembly drawing of the overall design concept. Part of the reason is because the concept would have to modeled with a helmet, which the team does not have geometry for, since one has not been selected. Additionally, the solar panels used are very flexible in reality, but cannot easily be modeled as such in SolidWorks; it would therefore be very difficult to show the panels mounted to the curved surface geometry of a helmet.
Team 29 does have the basic building block component of the design concept modeled, which is a series of 3 solar panels connected to a voltage regulator, shown below.
The design concept will involve many of these components connected in parallel and subsequently connected to a female USB port. The final number is not yet known, but for reference, two are shown below.
Team 29’s proof of concept activity involves wiring up a charging circuit and testing its electrical output. The solar panels are the “batteries” that power the circuit, and the voltage and current supplied by the circuit are the critical values of interest.
So far, the team’s PoC activity has shown that it is possible to produce an evenly regulated 5V through the use of a voltage regulator. However, the team has not been able to produce an appreciable current, and troubleshooting for this issue is ongoing.
Product Design Specification
Team 29’s product design specification defines the intended use, intended user, and specifications that the final product must meet. The intended use of final product is to provide energy to a GoPro or similar device using solar panels. The intended user is someone participating in outdoor activities such as skiing, snowboarding, or cycling. The design specification covers all aspects the prototype including: business, customer, product, usability, packaging, labeling, lifetime, safety, and regulatory requirements. These specifications were agreed upon for the purpose of designing and creating a cost effective, useful, and safe product. The product will not be considered complete until these specifications are met.
The purpose of Team 29’s project is to be able to supply people who love being outdoors with the ability to charge their electronic devices, which include anything from cell phones to GoPro cameras. The idea spawned from the lack of marketable green energy chargers that are mobile enough for the most active of people. Overall, the solar charger designed by Team 29 can be easily attached to helmets, bags, backpacks, and other carried items, and will provide enough charge to keep a device’s battery alive for an extended period of time. The solar charger does not necessarily have to be only for outdoor specialists, either; the project mission is to supply people who have a decent amount of daily exposure to the sun with the opportunity to place the mobile charger in a location that can actively power their electronic devices. The device can be used during simple activities such as walking or biking, and can be put in and out of use quickly to ensure an easy transition for the user. For anyone looking to purchase an effective, green energy charger that allows for ease of movement and versatility away from outlets, this product will be the perfect purchase.
The main feature of Team 29’s project is the ability to use solar panels to provide power to a portable device, namely a cell phone or GoPro camera. This will be completed using a circuit of solar panels and voltage regulators to ensure that the panels always output five volts (the designated input voltage to charge those devices) while maximizing the current output. The circuit will feed into a female USB port which can then be connected to the device being charged.
The next important aspect of the project revolves around its portability. The primary intended use of the device is to attach it on a helmet during extreme sports (e.g. skiing, snowboard, cycling, skating). In order to complete that task, the solar panels must be flexible, allowing them to fit cleanly and tightly on a helmet to get the maximum charge possible from the device.
However, the portability goes beyond using the device on a helmet. Team 29’s design features multiple deployment methods, meaning that it should be compatible with other surfaces. Using a Velcro backing, the product will be attachable to other surfaces, such as a backpack, with potential to also be mounted in a car or used as a stationary charger.
The final major characteristic of the project will be its storage capabilities. Team 29 will create a box that can hold the device when it is not being used. The box will be lightweight and compact enough to allow the device to be transported with ease. Additionally, this case can be used as a surface for the product to rest on as a stationary charger.
The project will have to be created safely as it deals with electrical components. This means properly insulating and securing loose wires as well as making sure that all soldered joints are secure. The device must also have some sort of coating to shield the electrical components from extreme weather such as rain and snow. Finally, Team 29’s product will feature some customization features; this will hinge on consumers being able to remove components and add new ones without needing to solder. This feature will also have the added benefit of making the device more amicable to consumers, because breaking one component will not mean that the entire device is useless.
Assembly of the LPH portable solar charger began with the building of the solar cells. The solar cells are comprised of two solar panels wired together in series along with a voltage regulator. These three components are connected with 28 gauge wire and the wire is soldered to each component. After the components are soldered together, the solder joints are dipped in plastidip to weatherproof the joint. Next a strip of Velcro that has an adhesive back is attached to the back of the solar panels. Once all these steps are complete a solar cell is complete.
Next phase of building for the LPH portable solar charger was to lay up the other side of the Velcro on to the helmet. The placement of the Velcro was determined by laying the solar cells on the helmet using double sided tape. Once the location of the solar cells was determined the other side of the Velcro was attached to the helmet via the adhesive back on the Velcro.
After the helmet was situated the team began to the assembly of the PCB Box. The PCB box houses all of the voltage regulators and the female USB port. The voltage regulators get a male header soldered to the voltage out and ground nodes. This header is plugged into a female header that is soldered to a PCB that was designed with help from an electrical engineering student and then printed through OSH Park. The PCB is then screwed on to mounts inside the PCB Box. The PCB Box is a box that was designed in SolidWorks and then 3D printed in the DeLaMare Library. The Box is designed to be as water and weatherproof as possible. Inside the box a closed cell foam gasket is used to help increase the water and weatherproofing of the box. There are two nodes at the end of the PCB that is closest to the female USB port that get wired with 22 gauge wire to the USB port to allow power to run to the device that is plugged in. Next the voltage regulators are plugged into the header and the wires are routed through the designated wire entry on the box. The top and bottom of the box is then screwed together.
Testing and Results
The final product was tested in three ways: the apparatus was probed (with a digital multimeter) for voltage output, probed for current output, and finally, connected to a phone via USB charging cable. To be considered successful, the voltage output needed to be 5±0.25 V, the current output needed to be in excess of 500 mA, and the phone needed to display a “charging” message. The readings were taken twice: once on a very sunny day, and once on an overcast day. On the sunny day, the device succeeded in each category, outputting approximately 850 mA at nearly 5 V, and successfully causing a phone to display a charging message. On the overcast day, the device succeeded in outputting the correct voltage and causing a phone to display a charging message, but failed to produce a sufficient amount of current. This failure is somewhat expected, since the device relies on solar exposure to produce electricity. While this is technically a product failure, it is considered an acceptable one; the team cannot force a solar-powered product to work when there is not enough sunlight. Furthermore, while the current was below the specified threshold, it would still be enough to trickle charge a portable device, thus extending battery life. Since the essential goal of the product was to extend the battery life of portable electronic devices, the results of these tests represent an overall success.
While the device has not yet officially been tested by any potential end users, it received enthusiastic reactions from attendees of Innovation Day, many of whom were GoPro owners. Since the device was built around the concept of charging a GoPro, this feedback is indicative of how end users would feel about the product.
Meet the Team
Kevin was born and raised in Pahrump, Nevada and graduated high school there in 2011. He is currently in his last year pursuing a degree in Mechanical Engineering with a minor in Statistics at the University of Nevada, Reno. He is also currently involved ASME and is the president of the Human Powered Vehicle Club. After graduation, Kevin hopes to find a career in a field he finds interesting.
Max Pullman was born and raised here in Reno. He has a fairly large academic background, as he previously attended Whitman College in Walla Walla, Washington pursuing an Applied Mathematics degree. However, at the University of Nevada Reno, he tried something new. In the mechanical engineering department, Max currently have a 3.94 GPA. In addition, he is an active participant in several extracurricular groups around campus, such as the Esports club and ASME. Looking towards the future, he hopes to be working on the design and mathematical modeling of gambling machines such as slot machines. If anything else, he would like to work on combining statistical analysis with large manufacturing mechanical design.
Honi Ahmadian was born in Tehran, Iran but has spent the majority of his life living in Reno. He is currently pursuing a Mechanical Engineering degree at the University of Nevada, Reno, as well as minors in Math and Unmanned Autonomous Systems. Honi is currently applying to graduate schools in order to pursue a Master’s Degree in Aerospace Engineering. In the future, he hopes to work in industry, especially in the design of spacecraft or airplanes.
Jordan was born and raised in Reno, NV. He graduated high school in 2010 from Spanish Springs High School. After high school Jordan attended TMCC for their welding technologies program, where he excelled in welding and placed in the top 6 at the 2012 US Weld Trials. In 2013 Jordan transferred to UNR to pursue a degree in Mechanical Engineering. After graduating Jordan hopes that his welding and engineering knowledge will lead him to a successful, lifelong career. He really enjoys off-road fabrication and hopes that he can use his combined knowledge in that field.
Joseph is a Reno native, having lived around town for 22 years. He graduated from Spanish Springs High School in 2012 and began his college career immediately after, and is set to graduate from UNR in Spring of 2017. He is a Presidential Scholar and a six-time Dean’s List recipient. After graduation, Joseph is considering pursuing graduate school options, as he has always found the research and academia aspect of engineering to be more appealing than a desk job.
LPH would like to thank the several different instructors, grad students, and fellow undergraduatestudents who helped with this project. Without this help, a completed prototype would not have beenpossible.