*Summary* - *0:00** - Topic:* Importance of Instantaneous Power Flow - *0:04** - Context:* Discussion on average power, RMS power, and instantaneous power in electrical circuits. - *0:11** - Acknowledgment:* Special call-out to Thand Nyan and Yor Nazal, first members of the KZfaq membership program. - *0:28** - Circuit Example:* Power supply or socket in a house, with current flowing into a load (e.g., fridge, washing machine) using AC power. - *0:51** - Waveforms:* Voltage and current waveforms shown at 1 Hertz for simplicity (typically 60 Hz or 50 Hz in houses). - *1:17** - Equations:* Phase difference between voltage and current demonstrated, with equations showing power as the multiplication of voltage and current. - *1:45** - Mathematical Transformation:* Conversion of the product of two cosines into a sum of two cos terms. - *2:06** - Instantaneous Power Analysis:* Power waveform generated by multiplying voltage and current waveforms, highlighting the average and instantaneous power. - *2:50** - Negative Power Periods:* Instances of negative power corresponding to opposite polarities of voltage and current. - *3:13** - Circuit Implications:* Power flowing back from the load to the source during negative periods, necessitating circuit design considerations. - *3:49**, **4:27** - Extreme Cases:* - Alpha = 0: Voltage and current in phase, power always positive, typical of purely resistive loads. - Alpha = 90°: Average power zero, significant current flow possible, indicative of purely reactive power. - *5:10** - Design Considerations:* Importance of accounting for high current in circuit design to prevent wire overheating and failure. - *5:43** - Further Topics:* Introduction to reactive power and its subtleties, with a promise of future videos. - *6:09** - Phase Offset and Power Direction:* Simple formula to calculate the proportion of time power flows in the opposite direction, based on the phase angle. - *6:44** - Conclusion:* Invitation to like the video, subscribe to the channel, and visit the website for more categorized video listings.

Thank you for clearly explaining this! I opened up a dead led light bulb last week and found no rectifier, just a 10.5 ohm resistor. I noticed the same in a cheap, plug in, 5v usb supply. I found something on the internet explaining that a resistor caused positive power but not why or what could be without the resistor. I love it when the universe supplies me an answer I didnt know how to find. I'm eager to see the rest of your videos on this topic! Thanks again!

And the amplitude of the voltage is always higher? Is there a specific factor? Thank you.

What impacts the phase difference between U and I? Many Thanks

I hope there could be a lecture on the battle of the current 😂

Is this the reason why in the power grids the frequency is monitored so closely? If the frequency goes down then also the phase shift between current and voltage changes? And then we dont have the expected power flow?

Thanks, when P is negative, what does that mean for the load? I would say the energy gets negative to E=P*t - how does the load handle the negative energy? Thank you.

Are we supossed to achieve a spacial phase difference or at least avoid a special difference? Or just accept that it is there? Thanks

RMS power is something useless (referenced in 2:35). Only involved with audio systems (fake). Only Mean or Average Power has significance in electric circuits..