#11 š From Atomet to Frenetic and EMI reduction at Flyback
The Newsletter of High Frequency folks
š Hello! Dr. Molina here! šØāš§
š¤ Thank you for reading and welcome to the show my Newsletter. Iām the CEO of Frenetic, we help great companies to find, design, and manufacture all their magnetics. We have a free trial of our Online Simulator, just register on our web and enjoy it!
Today I will talk about:
š Our path from Hardware minds to Frenetic minds.
š We will continue with the EMI at Flyback
This week there is no space for Product, therefore, I have planned a bonus edition soon š¤.
Before starting, Iām going to ask you for a favor, if you enjoy the material I create every week, a good sign for encouraging me to continue is subscribing and, itās freeee!!! Thank you! š¤
From Atomet to Frenetic
In edition #4, I talked about Deep Tech companies. These companies are created by Scientifics or Ph.D. candidates, which have a vision about the technology they have been researching and they were envisioned a potential business. The risk of this venture used to be very high, but the potential success could be huge.
I have spent the last 5 years talking about these businesses with my friend and partner Francisco Berlanga and now I can see the path traveled in our minds.
At the beginning, I was a 100% Hardware guy. I rejected any idea related with creating a software company. I created a hardware product with a software application. The scalability of the hardware is low. You need to build hardware anytime to want to sell it.
As a Power Electronics engineer, my mind was set up as a hardware engineer. I always thought of hardware for solving problems. I was mind-limited.
However, in 2017 I started talking with Alfonso (Current CTO at Frenetic) about the problem of magnetics and how to solve it.
As a hardware engineer, I started looking for hardware solutions, again š¤.
We created new magnetic materials, shapesā¦and probably a lot of other stuff I donĀ“t remember now. We were wasting a lot of time.
Our First toroid with Atomet
The technical results didnĀ“t have any sense, we burnt the 3D printer while printing magnetic material for 12 hours. The resultant core wasnĀ“t for an industrializable product. Then, we used other techniques. In the picture below, you can see our first toroid with our own material Atomet.
Then, Alfonso started writing some code to automate some basic calculations for our own materials. We can say, Frenetic was born by accident, writing some code for automating some crazy ideas.
After these experiments, we started thinking about how to create better magnetics with the current materials and shapes in the market.
š Then, we started writing programs for optimizing magnetic designs. The AI will come later (Thatās for another post).
And that was how I ended up using software for solving a hardware problem for the first time.
Coming back to the conversation with Francisco Berlanga, we continue thinking about how powerful Deep Tech companies can be and how long the path to find a scalable product is.
In comparison with other businesses, with clear products from the beginning (CRMās software, Logistics, Delivery), where the market could be a red ocean with hundreds of competitors around, Deep Tech used to be a blue ocean. However, if a company wins in one of those competitive markets, they grow like crazy. In a reflection, he told me this quote.
I really like Deep Tech companies, but I also find it very exciting to see companies growing x10 yoy
_Francisco Berlanga
The main value of a deep tech, could be the technology itself, but eventually, I would love to see that projects to grow exponentially.
In conclusion itās hard to reconfigure your mind to find the right path to execute your vision but only those who leave their prejudice behind will survive.
_Me
EMI REDUCTION AT FLYBACK
In the previous edition, we talked about the origin of the noise in flyback and the reduction of the EMI noise attacking directly to the transformer construction using Shield layers and auxiliary shield layers. Today we will continue reviewing the TI document to quantify the EMI reduction.
Impact of Shield and Auxiliary Layers
The transformer of the picture is designed for the following specs:
65W - Flyback converter
Universal Input (Nominal 230 VAC, 60Hz)
19,5V output
Turn ratio 5
The complete specs are derived from UCC28630EVM572.
The transformer below includes both shielding methods.
*Considering layer 1 the closer to the central leg.
Between layer 1 of primary and layer 3 of secondary winding, there is an auxiliary shielding winding (layer 2) connected to the primary ground.
Between layer 3 of secondary and layer 5 of primary winding, there is a shield layer (layer 4) connected to primary ground.
The following Figure 3, shows the EMI measurement without connecting the shielding layers. As you can see the conducted measurements of the Quasy Peak (QP) and Average (AVG) measurements cross the limited lines. That means those harmonics will be attenuated by the input EMI filter which will increase in size.
In Figure 4, itās the same experiment, but connecting the shielding layers to the ground, allowing them to give a path to the noise to the ground.
The result is: The conducted EMI is reduced by 20 dB. Thatās a great improvement, because we can decrease the input filter and save space and weight.
An interesting comment not related to the EMI. They build two transformers with very similar construction to quantify the impact of the losses due to the Llk and the Rac. In one of the transformers, they include 14 additional tape layers to increase the Llk by 40%. The result of efficiency was 88.39 percent.
The same design without those 14 layers and 40% less of Llk has an overall efficiency of 89.03 percent.
The impact of having a 40% more Llk is translated in 0,64 percent lower efficiency. This demonstrate that not only having a lower Rac is important, but having a better coupling and storing lower extra energy has also impact.
(as always, if you donĀ“t find the pdf, send me a Linkeding message and I will send you the pdf).
If you want to verify your Llk and Rac, I invite you to use the free trial of Frenetic Online, here you have the link to register.
Definitions
By the way, the definition of Quasi Peak and Average in this context is:
*Quasi-peak detection weighs each component based on its repetition rate: the faster the repetition rate, the higher the weight is given to that component.
*Average detection provides the average amplitude of each signal component across its period
*source: EDN
Reference
As in the previous edition, I have based this edition on the work of Isaac Cohen of TI (TI Flyback design guide), a great engineer who has supported our research at Frenetic about core losses.
Thank you again for reading and if you liked this edition, donĀ“t forget to share it.
Thatās all friends!! I hope you have enjoyed the victory of Rafael Nadal at Australian Open as me, have a great week!!
Sincerely,
Chema š