Input Capacitor Selection for Power Supplies (Part 1)

This is Part 1 of our 3 videos about Input Capacitor sizing and selection for switch mode power supplies. In this video we talk about why we need input capacitors, what roles ceramics and electrolytics play and we will show on an oscilloscope, how the noise on our input voltage changes with varying amount of capacitance. In the next 2 videos we will show exactly how to calculate the amount ceramics and electrolytics that we need for a given specification.

[@johnjarvo5147]

I have been an engineer since 1978. I had forgotten so much over time. This guy is great. He reminds me of one of my professors (WWII Vet) who was straightforward in teach, demonstrate, practice. All broken down into steps. Great approach!

[@LapsetoTime]

❤️❤️❤️ Nothing better tuen a practice demonstration , Thanku sir

[@kasraeghbali]

One of the best power electronics channels ... detailed yet simple explanations ...فدایی داری آقا علی

[@BirichaLectures]

Merci 🙏

[@basaltnow]

I also want to say thank you. At the moment I am unemployed in Germany, had lost my job when covid had ended and the lovely Queen had died. I do not design smps too much as it was before. I frequently check on the vidios here to stay a bit in touch with the specialties one has to pay attention to designing new smps. Also the common mode EMC filter videos had helped me a lot.

[@yangli411]

Nice. Can’t wait to see part2.

[@gauravchaudhary2571]

Thank you for providing such informational video. Waiting for next video.

[@pere_gt__stgtsport5467]

Great content. Treasure of information. High quality everything. Thank you very much. And I am an amateur building my first "serious" power supply and it's easy to understand almost everything.

[@shekar9237]

Excellent!

[@jagmarc]

A suggestion to make trace clearer and show subtle detail is to put a DSO scope into averaging. It increases detail synchronous to the triggered dynamic load step timing, while suppresses switching noise. That way with averaging you can see more phase detail in the line/load voltage excursions, without seeing the converter switching noise (now asynchronous) blur the trace. By switching in and out averaging, can isolate and show and hide the converter switching noise

[@debasishtahbildar9603]

Eagerly waiting for the remaining part Sir... Hope it will come soon... Thank You

[@mohamedlanjri]

Very nice video, thanks for sharing. If I'm allowed to make a suggestion... You migth have copiright reasons to not do it but It'll be great if you can back up your videos with some schematics to see where are you connecting and disconnecting those caps.

[@leeslevin7602]

Brilliant, thank you.

[@craigpeckett4196]

Have you tried aluminium polymer capacitors instead? The lower ESR and ESL values allow them to filter the high frequency noise more effectively.

Thx for the videos, appreciated them a lot! Offtopic question: how is the current sensed at the demo board that is so "nice" (clear and steep)? Is there a rogowski coil or some other current transformer or something else? Thx for any reply.

[@noslidemais]

[@piotrekp90]

10:05 Do I see correctly, the new successor to the Bode 100 - the Bode 500 with N connectors and full 2 port measurements :D

[@bastiengranouillaclautrec9993]

Hi, I have a question : as the control feedback allows the audio susceptibility to be reduced of ||1+T||, I wonder if we could under-estimate the input capacity and rely on the robustness and the efficiency of our control design ? Thank you for this video

[@filips7158]

Generally not a good idea. The risk outweighs the cost largely.

[@JeromeDemers]

What is the name of that yellow box « ishing »?

[@SatyajitRoy2048]

Would have been nicer to see if proper probing technique was followed. That long ground lead of the probe is not good for measuring noise

[@ErkanGench]

Thank you for the valuable information but you are wasting too much paper. Can't you use a white board instead?