Bradley's Build Log

Hello everyone!

My name is Bradley and today is the day I break away from my old shell and get serious about learning electronics.

I started my electronic education in my early twenties. Graduated in 2010 with AS in EECS however I then decided to put my education on hold to find a job and help with the bills at home. But as time passed on, what became of my education started to become a foggy memory. With no practical work other than my time at school, I managed to land a job that was repairing consumer electronic devices thinking this will help me get a starting experience with the electronic world. During that time, I taught myself how to use DMM, soldering all the way down to 0402 and sometimes a 0201 SMD, how to find a blown cap on a power rail that has over 20+ caps in parallel, and even more - but there was always an itch in the back of my mind. How did they build this? What was the process they had to go through in order to create this product? What tools were used? Etc.

It’s now 2018, my birthday, and my girlfriend gave me a gift I never expected. Thinking to myself what it could be, maybe a new video game or the Destiny 2 Lore book I’ve been talking about. It was the Arduino Uno R3 starting kit. I broke down in tears but not of sadness but of overwhelming joy. Something I always wanted to try but never took that step. Because of that gift, it started a fire in my heart and pushed me to further learn about embedded software in AVRs, electronic design, building DCDC converters, what to look out for, maybe blow some of the projects up lol to understand what went wrong. My foundation is rocky and still a ton I need to learn to strengthen this foundation - but I’m so excited to be here and can’t wait to start learning more again.

I recently started listening to “The Amp Hour” during my long drives to work and special thanks to Chris for this opportunity to be here and recommending Ultralearning.

Thank you all for reading.

TL;DR - I want to learn electronics and embedded systems!

Hey Bradley, welcome! Really excited to see what you build. Looks like you have a great base to start from.

Have you started reading Ultralearning yet? I am curious about your thoughts and how that could apply to CE. One element I’d like to incorporate is the idea of “drills”, so I have been brainstorming that some more.

Thank you, Chris!

Yes, I have. In my case, I have the audible version of the book. Just finished up chapter 3. A couple of the biggest take away is to get uncomfortable and to seek feedback. Asking myself what really makes me uncomfortable. I’m sure like many, it’s engaging in conversation haha. I’ve been a lurker on forums for many years never one to engage in anything. Sometimes I would start to write something but to then stop midway to then drop it due to fear of maybe not understand something when it should have been a perfect time to ask. As Shia Labeouf once said - JUST DO IT!

I’m not sure what it was like in the very early stages of this website but to me, it seems you already been applying these principles from the very beginning that the book speaks about.

Love to know more about your idea of drills.

My drills of attack right

  1. Get uncomfortable. Try my best to be engaging in the build log and provide feedback.

  2. Learn more about DCDC buck converters. How to select an inductor for a given converter. I’ve always played around with regulators but never tried to build a buck converter. So my project is just a simple dc-dc converter and you know if I mess up somewhere I have a place to talk about it :slight_smile:

  3. Learn Kicad. I’ve been using CircuitStuidos for some time but there are some issues.

Here my work in progress of the buck converter

Yep, That’s a great one to remember. I find whenever I am avoiding writing code or doing something with RF (my two current learning vectors), it’s because I afraid of looking stupid and/or having to put in the work.

Awesome! Check out the PowerSwap course for guidance on this process

Hey everyone!

Just wanted to give a quick update on the buck build that using TPS560430. Its been a busy week!
Hope everyone is doing great!!

I’m currently in the direction of building modules to help create reusable designs for future projects. I saw a lot of stuff relating to EMI in DCDC converts. For something like this project should it matter? Like to know whats everyone’s thoughts are.

The other day I was thinking it would be cool if I could design something for our horses. Something like filling up the water buckets until said level and control it through my phone lol :smile:

Nice work

By the way, that LED with 2uA of current will probably not do any good :slight_smile:

Thank you kvk!

Wow :rofl: I didnt even realize that mistake. Just checked and it was a typo (or was it) lol. Suppose to say 510R.

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You know at 2uA, there are probably a few photons coming out…but yeah, you’d need to start building photomultipliers to detect them :smiley:

Great looking design! And I like that you are building up the reusable modules.

As for EMI, the biggest sources are going to be from not having a tight “loop” between the switch pins on the chip and the inductor. If you’re following the recommended layout, you’ll probably solve 80% of the problems. After that it will come down to the inductor shielding (if present) and any other place where current can’t get to where it wants to go.

Use shielded drum core, or you might have problems at those currents

Minimize the size of the switching node is always the first thing on the table to reduce EMI.

Thank you for everyone’s input! Gave me some thoughts to research on.:slight_smile:

Good to know Chris! Felt like I reread the datasheet a bunch of times to make sure everything was good and eval board user guide really helped out as well.

My whole BOM is built around Digikey at the moment. I figure I would get a few of them made over at JLCPCB, solder them up here then see how they play.

The Inductor of choice is SRN5020TA-120M. Since its 600mA Max circuit and 1.4A rated inductor which to me should be no problem but when I was playing around on TI Webench I notice it allowing me to pick an inductor with current ranging all the way up to +4A ex. MSS1038-123MLB. Also notice that DCR was a lot lower with coils with higher current ratings.

So really what’s stopping me from choosing something like that aside from cost and size?

As far as test equipment goes, I lean towards the microcontroller world and been playing with the stm32 Nucleo board. I currently only have DMM, bench power supply, soldering station, and hot air station. An oscilloscope and or logic analyzer is on my radar but likes to know what you guys recommend or add to the list of must-have.

For RF related stuff, A guy I work with is huge into RF and has a ham radio license and as interesting as it sounds when he talks to me about it, it goes over my head or smoke comes out of my ears haha.

Sure, you can use the bigger inductor. Penalty is cost and size as you wrote

Benefit is better efficiency, lower loss, lower thermal hot spots

For a bigger core, the flux density falls. Losses is about B uplifted to 1.7, so lower B field, a lot lower losses. Losses can be calculated from here:

Correction : B lifted to 2.7

Hello everyone! Wanted to provide an update on my first dcdc module. It works! :smiley:

When I placed my order with JLCPCB provide my Gerber and stencil to be 39x39mm. The very next day, I received an email that the audit failed and examples to me I’m missing the NC drill files in the Gerber. Fair enough and fixed that right away.

Couple of weeks go by and I get

Oh man, Im sure I’m not the first where this has happened lol.

Solved this issue by pulling out my tin snipper and made it into

Found a piece of scrap metal that has a nice 90-degree angle and tape to hold it all down lol.




I used a 12 ohm load (only one I have atm) and everything appears to be working great!
This was a lot of fun! Like to know your thoughts!

Thank you everyone :smiley:

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Did you reflow with a clothes iron? That is really clever!

Good idea on the tin snips! I always try to just use the entire thing and I get alignment issues. Then again, I have cut myself on stainless steel stencils (nasty slices) that I’m pretty careful around them in general.

Board looks great! I am curious about the iron as well

Thank you!!

What you guys didn’t see is when I first upset the iron, it tipped over and the board fell into the carpet haha. To my surprise, all the 0402 components were still on the board!! Few books later, I made the support for the iron. Definitely need a vise for this lol.

I guess I can say I reflowed the board base on “feel” started at the lowest temp and slowly ramping it up with the clothes iron then got my hot air gun set to 230c @ lowest airflow. Didn’t want anything flying off haha. For next time, recently bought a temp probe to get a better idea of what the temps are when I’m reflowing the next board.

In the past, I’ve reworked many SMT boards with hot air guns as well as bottom plate heater. Reading a datasheet that talks about the reworking process really helped me understand the process and seeing how manufacturers do it. When I first started out, it was trial by fire! I’ve burnt a lot of stuff by testing it on with E-scrap we had laying around. All in all, I learned a lot by just jumping in, and who doesn’t like the smell of a burnt PCB once in a while lol.

Have a good day everyone!

The iron idea is excellent. I might have to try that. I’m sure there’s an iron around here somewhere, and I’m sure no-one would mind if I used it for reflowing some boards…

Can you remember what it was that you read about SMT rework that was so useful?

I remember first seeing it in a manual that came with this BGA rework machine. Spoke about temperature profiles, how to set them up, and showed a profile chart.

We mostly could get by with air gun and or heat plate but when we needed to remove something complex without pulling pads to the BGA machine. Oh I tried for laughs to remove a processor with 529 pins on 8 layer board. 400c @ max airflow and 5ish minutes later. It was not the best let’s just say lol.

As far I’m aware, many manufacturers follow IPC-7530 standard when it goes through SMT assembly.

Example of a profile.

Hello everyone!

Hope everyone has been enjoying the holidays and staying safe out there. Just wanted to pop in and share a wip project. In a nutshell, it locks a door. There is a mainboard behind the scenes that will talk to this device via RS485. Here the top-level of the project so far.