Work logs will be posted weekly after the Thursday night meeting to recap what has been accomplished so far and what will be the next task at hand. To preface, team meetings are with me, Nathan Fisher, and Joel Diccion and are held at his house.
9/14/23
Recap
- Finalized that we will be choosing a Solid State (SSTC) design as opposed to Spark Gap (SGTC). That is to make manufacturing easier and tuning in the future easier.
- Discussed how much power we want the coil to draw and how we will use a voltage doubler in the rectifier.
- Ordered wire for both the primary and secondary circuits. Also cadded the toroid and tube for the secondary.
To work on
- Print cad designs
- Finalize BOM for the primary circuit
9/21/23
Recap
- Met with Dr. Pinar to have him review our proposed circuit design
- He taught us about the importance of bleeder resistors
- How and why voltage ratings work on capacitors as well as how ESR plays a role in heat produced
- He gave us an idea of how to find the resonant frequency of the secondary circuit as that will dictate what capacitance to use in the primary
- He’d recommend a DRSSTC as it seems more efficient than SSTC
- Some prints for the secondary circuit are done and wire is ordered
To work on
- Finish prints
- Start manufacturing the secondary circuit
- Start manufacturing inductor for primary
- Finalize BOM for the primary circuit (excluding interrupter)
9/28/23
Recap
- Didn’t meet with Joel because I was at a Lions game
- prints are done so toroid is ready to be wrapped and coil is ready to be spun
To work on
- wrap toroid
- spin coil
10/6/23
Recap
- Didn’t meet due to midterms
- Toroid is wrapped
- Started spinning coil, didn’t go well (the wire was crossing and snapping)
To work on
- Look into automation for coil-spinning
- Look for safety documents
- Put together mid-semester presentation
10/26/23
Recap
Welcome back folks, it’s been a while! Joel and I haven’t had a meeting in a while due to midterms, family visits, and club events. In today’s meeting, Joel shared his CAD files for the coil spin automator. I shared my research in power electronics and electronics to update on what works in our current design and what won’t work. Key takeaways from my research:
- traditional full bridge rectifiers don’t work for power applications as there is much distortion (could remedy this with filtering but inductors are big and expensive)
- IGBTs need to be controlled by a gate driver as opposed to going straight to the microcontroller due to the nature of RC circuits and microcontrollers having a high-input impedance
- to achieve 5V across the gate-emitter, it may be wise to electrically isolate the gate driver from the IGBT so that the gate drives can switch between 0-5 V as opposed to 120-125V
To work on
- Print CAD files for automation
- BOM for power circuit and gate driver circuit (excluding PWM signal generator)
- Be awesome
11/3/23
Recap
To summarize our meeting and progress in one sentence: We are cooking with gas!
- Meeting was held in OSHE lab to look at our glorious prints
- Coil spinner is in full production, expected to be assembled by Tuesday
- Circuit for the coil is finalized, BOM has been made, and parts are ordered
To work on
- Wait patiently for parts and mentally prepare for some soldering
- Help Joel spin the coil once production is finished
- Start brainstorming on how we want to prototype the primary’s turns
- Think and research safety before any circuit goes live
11/9/23
Recap
We spun the coil today. It took about an hour to figure out how to use the automater efficiently but went swimmingly after that. We also applied the first layer of varnish to the coil so that it stays in place, and our order for the circuit components came in.
To work on
Our next meeting, we will have a couple of layers of varnish on the coil and we are going to find the resonant frequency of the secondary
- keep applying varnish layers
- start soldering (expecting to finish over Thanksgiving)
- start safety document
- start housing unit for coil components
Start of Spring semester
To recap from last semester, the power circuit was not functional due to faulty soldering. The issue was that we needed low gauge wire because this is a high current application but the low gauge made for great heatsinks which is ideal for use but not for soldering. This semester, we plan to create a single PCB to make soldering manageable. We also have a 3rd team member, Tom.
1/25/24
Recap
We caught Tom up on what we’ve done so far. Pondered what went well and what could be improved on from last semester. We created our team contract and ranked our priorities on what’s most important and what can wait. I’ll be starting the PCB in KiCad, Tom is starting coding in Arduino, and Joel is designing a control module circuit.
2/1/24
Recap
Joel and I met with Shane to get a crash course on KiCad (Tom had class). I started the circuit. All symbols are in and the pins are connected. Footprints are to be added soon. Tom started Arduino code, and Joel started the Faraday cage.
2/19/24
Recap
Tesla coil has been on the back burner for the last 2 weeks. I finished the pinout of the power circuit in KiCad. All components have footprints now and I have begun the physical layout and routing in KiCad. I set up a meeting with Shane to familiarize myself with footprints for common devices. We are also pushing the CDR presentation this week so are busy with that.
2/22/24
Recap
The three of us did our critical design review slides this week. I helped Joel troubleshoot his driver board. He was using a sine wave to test our IC, but I had the idea that the IC might be looking for rising and falling edges and that’s why the board wasn’t doing what we expected it to. Once we changed the test wave to square, the IC did what we wanted it to do. With this newfound knowledge, we know we need to digitize our feedback signal on the coil.
3/16/24
Recap
The board is done in KiCad. A design review is scheduled with Shane. If he green lights it, then we will order it. We also made an order sheet for miscellaneous parts.
3/23/24
Recap
The board is ordered as well as some miscellaneous electronics. International shipping is expensive.
3/29/24
Recap
No update from my end. Waiting for parts.
4/6/24
Recap
PCB came in. It is almost soldered already! We have our power cord ready. I will finish soldering, make the power cord look good, and troubleshoot as need-be next week.
4/11/24
Recap
Finished soldering the PCB. Joel found an error I made in KiCad. One of the diodes that connects to the IGBT is reversed polarity of what it should be. The diodes we bought for the circuit were thrown out during a lab cleaning so we had to improvise what was lying around. Found a diode that is the same electrically but doesn’t have the same terminal diameter. Finished soldering the power cord that we thought was going to come fully assembled. Most of my bandwidth is focused on doing the final report and presentation stuff while Joel finishes the gate driver circuit and prints a gaussian cage.
4/20/24
Recap
We verified the power board yesterday. We used the lab’s variac to verify that the measured voltages match the theoretical voltages. Using the variac enabled us to start with very little voltage in case there was a mistake somewhere. I reversed one of the polarities on my rectifying capacitors which caused a short and blew our safety fuse. We knew it was the capacitor because once they were both drained, one was noticeably more hot than the other. After fixing that error the board was verified and our results were documented for our report.
I also worked on a prototype for an IoT website, designed and simulated the audio jack input circuit, and am compiling research on why a faraday cage is necessary.