Basics of Thermal calculation, measurement and simulation

[@igorspiridonov6539]

Perhaps due to the fact that the thermal resistance of the thermal paste is not equal to zero, which is why there was some discrepancy. And very good video, thanks

[@WalidIssa]

You will be a great channel

[@visai3634]

Fantastic video explaining thermal calculation. Keep up the good work

[@thezodiace7399]

one of your early subcribers, keep up the excellent content.

[@FesZElectronics]

Thank you for supporting! I'm happy you enjoy the content. I try to improve my content and video-work the best I can. Let me know if you noticed anything that would still need changing.

[@himanshushukla7587]

how can we calculate copper area on pcb for heat transfer.. or this video shows heat sink for heat transfer if we can use copper pad (open masking) then how to calculate PAD size ..

[@kieranj67]

Thanks again for another excellent video. You have explained very well a concept that I never fully understood, thank you

[@FesZElectronics]

I am happy you liked it! Let me know if there are other topics you might find of interest

[@kieranj67]

@@FesZElectronics Thank you!!!. I discovered you way back when I was trying to find a solution for OpAmp stability. I was building a programmable power supply using a PIC, a DAC, an Opamp and a Transistor - it was actually a dual +/- supply and it seemed to work perfectly for a few seconds and then the outputs began oscillating - I kinda figured eventually that it was due to delays in the feedback to the Opamp. I found a few videos on KZbin, two in particular on how to resolve the issue but both were beyound me. The 1st one which offered hope was from "SN3 Innovations" but I could not yet get my head around finding a solution. I'd say there is lots of people like me that tried building a programmable Power Supply but got burnt with not fully understanding Opamp Stability. If you could find time in the next few months / years to create a video showing the pitfalls in attempting this and any simulated solutions, that would be fantastic and I am happy to reward you either financially or with a piece of equipment you would like to have, Kieran

[@FesZElectronics]

Hello Kieran! Interesting problem, I'm guessing you used NPN type of transistor on the positive rail and PNP on the negative? in that case your problem might be resolved by adding a capacitor over the op-amp (output to negative input) this should slow it down a bit by turning it into an integrator (10-100nF should do). On the other hand if you built LDO type regulators (PNP on the positive side and NPN on the negative) the usual solution is to have output capacitors with low ESR (ceramic or tantalum); using only electrolytic ones is not recommended since those have large ESR by default. If you want, you can send me the schematic and I will try to find a proper solution and explanation (my email is [e-mail]) - that should provide you with the fastest answer. I am not sure when I will get a chance to turn this into a video but I will do my best! Let me know if there where any other problems you ran into - I think that if I gather all the things that can go wrong its easier to show specific simulation methods and highlight what the "right way" is. Also if you want to try the academic explanation here is a great document on the subject from Ti: www.ti.com/lit/an/snva020b/snva020b.pdf

[@incxxxx]

Very good lecture.

[@AhmedKhamis47]

First of all, this is a very helpful lecture but you said that the Heat sink thermal resistor should be in series with junction to case resistor and in the final simulation u put it in parallel with the case to ambient resistor

[@FesZElectronics]

Hello Amhed Khamis! You are right, the reason behind this arrangement was that heat goes from the source (the junction) to the case (R_JC), and from here there are 2 ways of going to the ambient - first directly (part of the transistor case is exposed to the ambient) (R_CA) and second trough the heat sink (R_HS); this is why the 2 resistors are in parallel. The R_JC is in series with both the R_CA and the R_HS its just that the R_CA and R_HS are in parallel.

[@incxxxx]

Small letters are not visible, I simply guess them.Really, its hard to decipher all this.

[@FesZElectronics]

I'm sorry to hear that, next time I will be sure to use the pen, since it offers better contrast, and also try to write nicer and a bit larger. I always had horrible hand-writing in school...