Power Scraping Module Team Shahzaib Shahid Jordan Fox

Power Scraping Module Team: Shahzaib Shahid, Jordan Fox, Xiangyu Cao, Andesen Ande, Ahmed Salem and Benjamin Yoko Client: Honeywell Faculty Advisor: Prof. Gary Tuttle

Project Vision ● Research and develop a device that will efficiently collect, convert, and store low voltage energy. ● The purpose is to provide an alternative self-power source for devices. ● The goal of this project is to take a small, unusable AC voltage as a source and convert it to a usable DC voltage that can power various components in a system. ● The project can be used for many wireless applications like remote sensing, battery-free remote sensors for HVAC control and building automation etc.

Market Survey ● There is a huge demand for Low Power Harvesting Devices. ● Most of these harvesting devices are used in hard to reach areas like: ○ Remote Control Monitoring Systems. ○ Implantable Devices. ○ Equipment Monitoring.

Conceptual Sketch

Functional Requirements ● Converting 1. 1 V AC Peak to Peak Voltage to 3 V DC. ● The input signal is the only power source for the device Use a source or method that can be adjusted from 1. 1 Vpp to 0. 2 volts Vpp. ● ○ lowest possible input ● Include a charge indicator in the output of the device

Non-Functional Requirements ● The system should be as efficient as possible. ○ Minimize loss ○ Determine for every hour of energy scrapping, how many minutes will we be able to drive a 20 m. A LED. ● Stretch goals: ○ Produce output of 5 V ○ Use harvesting device as input

Technical Constraints ● Finding diodes that have low barrier voltage ● Finding a boosting device that can take very low input voltage for amplification to the required 3. 3 V ● Use Half wave or full wave rectifier to consider for voltage drop. ● Low input to boost the voltage to the required level due to loss during rectification ● What should be the capacitance of the supercapacitor to account for the time it takes for it to charge the circuit.

Project Plan ● Identify requirements ● Define system overview ● Research system implementation ● Identify components for prototype implementation ● Verify individual component functionality ● Construct first round of prototypes ● Verify prototype functionality

Functional Decomposition 1. Rectification - Using Schottky diodes to convert the AC input signal into a DC signal 2. Voltage Boosting - Using a DC-DC booster, increase the low-level input to a higher voltage level 3. Energy Storage - Store the charge into a long-term storage component (supercapacitor) so that it can be used when desired 4. Charge Indicator - Add an indicator (LED) to signal that the energy storage device is being charged

Conceptual Design Diagram

Component Selection Our conceptual design includes the following components: ● ● ● An input source - Power supply in lab (for testing/simulation) A rectifier - Schottky diodes A booster - Low input DC-DC voltage booster A supercapacitor - 1 Farad, 5 V 20 m. A LED

Test Plan ●Testing in two phases: ○ Component testing ○ System testing ● Performed with Iowa State University lab equipment ●Components tested ○ Schottky Diode ○ Supercapacitor ○ DC booster

Component Testing ●Diode ○ Verify cutoff voltage ○ Rectification test ●Capacitor ○ Verify capacitance ○ Charge testing of capacitors ●Booster ○ Verify boosting effect

System Testing ●Output test ○ DC output ○ At least 3 V ●Function test ○ Power LED ○ Verify LED time vs charge time ●Efficiency test ○ Energy out vs energy in

Testing Parts

DC-DC Voltage Booster ● Using Low-Voltage DC-DC booster obtained from Sparkfun (PRT-10255) ● Testing yielded several issues: ○ Failure to boost ○ Transient behavior ○ Inconsistent results

Booster Testing In the booster testing stage we verified the functionality of the booster between 1. 1 V and 1. 6 V DC input. However the required input is below this range. Potential Solutions: 1. Email manufacturer and ask for a solution. 2. Build our own Voltage booster.

Capacitor Testing ● The capacitors were tested with the circuits shown here. ● From the results, they are acceptable for use in or design.

Rectification Circuit The full wave rectifier circuit provide the most stable output but since the booster stage is not chosen yet, we are not able to determine which design works better in terms of power efficiency in the overall system. Full wave rectifier with smoothing capacitor has about 0. 4 V forward voltage drop Full wave rectifier without smoothing capacitor has about 0. 4 V forward voltage drop Half wave rectifier with single diode has about 0. 25 V forward voltage drop

Plan for Upcoming Semester

Individual Contributions Shahzaib Shahid- Project Lead: Booster Testing Jordan Fox- Chief Engineer: Project Design and Modification Andesen Ande- Report Manager: Documentation Ben Yoko-Test Engineer: Supercapacitor Testing Xiangyu Cao-Test Engineer: Rectification Testing Ahmed Salem-Test Engineer: Full Integration Testing

Questions?