Tesla Coil Security System 2.0

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Sponsors Dr. Herbert Hess
Team Name Security Shock Door (SSD)
Duration Fall 2020 - Spring 2021
Faculty Adviser
  • Dr. Herbert Hess
  • Dr. Li
  • Abdallah Smadi
Client
  • Dr. Herbert Hess
Graduate Mentors
  • Ian Glasglow
  • Phillip Hagen
Team Members
  • Justin D. Stephens
  • Connor Radford
  • Andrea Cardona
  • Nico Piccioni

The goal of the project is to design and construct a working prototype for an electrified security door.


Problem Definition[edit | edit source]

Design a system that causes high voltage arcs to pass across a doorway in a manner to discourage people from entering.

Background[edit | edit source]

Currently, security systems are pretty lackluster when it comes to intimidating intruders. The average system consists of locks, cameras, and motion sensors. The goal of Security Shock Door is to construct a new security system utilizing a NASA built Tesla Coil arrangement to produce visible lightning bolts across a doorway; providing the alternative of a passive defense by having a strong intimidating presence. We will be building a demonstration unit that shows our application of intimidation.

Deliverables[edit | edit source]

- Agreement between team members for acceptable protocol and etiquette

- Breakdown of the intended funds for the project

- Documentation of the multi-functional requirements of the system

- Intended plan for time management of the project

- Description of the planned experiments and validation testing planned to confirm the intended design

  • Concept Design Review

- Formal "progress update" of the design for the project

Specifications[edit | edit source]

The final design of this project should meet the following qualifications/Specifications:

User Interface Design

  • Arm/disarm the security system
  • Electing to ground to frame or potential intruder
  • Sense an approaching intruder

Mechanical Design

  • Use of a wooden door frame because of non-conductive properties
  • Use of replaceable arc nodes for maintenance

Electrical Design

  • Operate at a frequency of around 4 Hz
  • Arc from one side of the door to the opposite side horizontally
  • Sensors for detecting an incoming intruder
  • Appropriately sized Tesla coil
  • Controlling grounding of non-source nodes

Safety

  • Scare away the intruder without serious injury or death
  • Minimal risk of unwanted shock while the system is armed
  • Effective arming/disarming feature

Budget

  • Keep the cost under $800

Design Considerations[edit | edit source]

Project Learning[edit | edit source]

Node Manufacturing[edit | edit source]

Although Nico had selected gold plated copper with a nickel undercoating as the best and most conductive material for our nodes, we are changing the design of our nodes so that the electrical arcs will have less interference with each other. Due to time constraints, we will now be manufacturing the nodes ourselves so they will most likely be made out of aluminum instead of gold-plated copper for demonstration purposes.

Figure Description
Finished Source Node
  • Final design of Source Node

Solidworks Modeling[edit | edit source]

Justin has been working on modeling the door frame and designing the source and ground nodes as to provide an accurate representation of our intended working space, and to manufacture our custom arcing nodes.


Door Frame

Due to COVID the ability to determine the sizing of our work space is highly valuable and something that will continue to be needed as our lab space is closed to in person activity. All of the surfaces of the doorframe have been constructed even down to the door hinges in order to provide as accurate representation as possible.


Arcing Nodes

After much deliberation between our mentors, Ian Glasglow and Philip Hagen, and between Connor and Justin we determined that a sharp/pointed source node and a smooth hemispherical grounding node would be best. This allows for the current to build up and be focused through the point of the source node and then be released when the arc is generated in between the two nodes, See Feko Simulation "Cone to Cone" and "Hemisphere Receiver" respectively for images.

Figure Description
Solidworks Door Model Closed
  • Solidworks door model in the closed position.
Solidworks Door Model Open
  • Solidworks door model in the open position. Note: See properly modeled door hinges on the right side of door.
Solidworks Door Model with Electric Representation
  • Solidworks door model in the open position. Note: The blue rods passing horizontally over the door is a physical representation of what the final designs electrical arcing should look like.
Solid Grounding Node
  • Solidworks model of grounding node to be made out of aluminum.
Wireframe Grounding Node
  • Solidworks model of grounding node with wireframe visibility to show female threaded tapped hole in bottom (To screw node onto door frame)
Solid Source Node
  • Solidworks model of source node to be made out of aluminum.
Wireframe Source Node
  • Solidworks model of source node with wireframe visibility to show female threaded tapped hole in bottom (To screw node onto door frame)

Heat Management[edit | edit source]

Nico has been working on managing our current over heating dilemma with the current Tesla Coil design. After a lot of research on heat transfer and heat management methods, Nico has come to the conclusion that liquid CPU cooling would be the best method for keeping our transistors from overheating, however, proper heatsinks are sufficient and are much more cost effective. After performing multiple tests on various types of heatsinks, Nico has selected the most efficient heatsinks to keep our transistors from overheating.

Figure Description
Heat Sink Options

Tested heat syncs were all heated on a hot plate at 208°F for 1 minute, then temperature taken with thermal imaging camera. Results shown below

The Four Tested Heat Syncs (Top to Bottom)

  • Large Flat
    • 160.2°F
  • #1 Piece
    • 142.4°F
  • Long Fin
    • 169.6°F
  • Original Heat Sync
    • 182.2°F
Heat Sync Front View
  • Front View of Heat Sync
Heat Sync Top View
  • Top View of Heat Sync
Heat Sync Top View 2
  • Secondary Top View of Heat Sync
Vertical Circuit Board Front View
  • Circuit board attached to vertical acrylic board to aid in airflow, front view
Vertical Circuit Board Back View
  • Circuit board attached to vertical acrylic board to aid in airflow, back view

Circuit Board Reverse Engineering[edit | edit source]

Andrea has been working on the behavioral simulations of the Tesla Coil circuit that was acquired by our team. She mapped the components from the physical circuit board into LTspice and was able to verify the input and output voltage of the system. Because of the complexity of the circuit, it took 12+ hours to run a full simulation at full scale however, a change in the simulation command was made to shorten the simulation run time. This provided quicker results, but the results were scaled. Having researched and confirmed that the output voltage is within range for the design of the secondary load, that value may be simulated further to demonstrate that our electric arc will meet our objective.

Figure Description
Circuit Disassembly
  • Partially disassembled circuit board that runs the Tesla coil.
Circuit Schematic
  • Finished LTSpice Circuit Schematic

FEKO Simulation[edit | edit source]

Connor has been working on simulations of the behavior of the Tesla Coil. All the work so far in Altair FEKO is strictly to gather behavioral data which means nominal values are being normalized and converted to decibels. Along with that the general setup for the tesla coil model is very simple. It has a turns ratio of 1:100 and a source of 120V attached to the primary coil. This will be changed in future testing when reverse engineering the physical tesla coil is completed and modeled in other software. The behavior that has been tested is to see how electric flux density is distributed on different emitter shapes, how intense the electric field is in between the emitter and receiver, and how the electric flux density is distributed on the receiver. Results so far show expected behavior.

Figure Description
Cone Plate Bias
  • Electric Flux density on a negatively biased receiver plate. Also includes Electric field segment between emitter and receiver.
Cone to Cone
  • Electric Flux density on emitter and on receiver cone. Also includes Electric field segment between emitter and receiver.
Simple Coil
  • First model made to benchmark expected behavior. Electric flux density on a sphere emitter.
Preexisting Node Model
  • Tried finding preexisting parts online to be used as nodes. This was one of the better options but before buying it was setup in Feko for testing.
Preexisting Node Field Analysis
  • Near field analysis visualizes this node’s undesirable field densities. This node will not be implemented into the final design.
Hemisphere Receiver
  • Added voltage biasing to the hemisphere receiver. Results show a higher charge density all around the hemisphere along with multiple hot spots appearing as well.
Receiver Node
  • Changed receiver node to a hemisphere instead of a disc. Results show more reliable and predictable charge density. With some modification this Node will be implemented into the final design.

Raspberry Pi Touchscreen Security Terminal[edit | edit source]

For this project the desire to put the control of the power to the system behind a form of authentication platform was very apparent. This showed how the system could be integrated into a system that was already in place and provided a method for use to safely demonstrate the system during expo. In order to do this Justin worked in conjunction with Connor and Phillip to construct a python based GUI that would be displayed and controlled on a Raspberry pi powered touch screen. The code for this terminal was fairly simplistic however the actual final touches were very finicky and was when Connor and Phillip’s assistance was required.

Video Demo

Figure Description
Security Terminal
  • Python based Raspberry Pi touchscreen security terminal

Team Members[edit | edit source]

Security Shock Door Team Photo.jpg

Security Shock Door Photo Justin Team.PNG

Justin D. Stephens

Major: Mechanical Engineering

Hometown: Oregon City, OR

Responsibility: Solidworks Modeling, Wikimaster, Security Terminal

Email: Step5888@Vandals.UIdaho.Edu


Security Shock Door Connor Team.jpg

Connor Radford

Major: Electrical Engineering

Hometown: Spokane, WA

Responsibility: Feko Modeling

Email: Radf2235@Vandals.UIdaho.Edu


Security Shock Door Photo Andrea Team.jpg

Andrea Cardona

Major: Electrical Engineering

Hometown: Burley, ID

Responsibility: ADS Modeling

Email: Card5013@Vandals.UIdaho.Edu


Security Shock Door Photo Nico Team.jpg

Nico Piccioni

Major: Mechanical Engineering

Hometown: Eagle, ID

Responsibility: Material Selection and Heat Management

Email: Picc5382@Vandals.UIdaho.Edu

Additional Documentation[edit | edit source]

Project Schedule

Gantt Chart

Critical Path Planner

Reports

Final Design Report

Meeting Minutes

Meeting Minutes Folder

Presentations

Presentations Folder

Final Expo Presentation

Expo Poster