I have searched a lot about the concept of I2t and I didn’t understand. However, I understood now partially. I will watch your video again and again because I am slow learner. Thanks for the video.
I always pondered about modeling a thermal breaker or fuse using a single RC circuit like this and using a low-pass filter of current flow through a shunt and a comparater controlling a pass transistor to make an active fuse, though such chips already exist of course
Considering the case of open loop voltage mode PWM smps..the inverse...i.e. I (current) ×√time (in secs) (1000*1000u secs) can be implemented similarly for a " pulse by pulse" protection thereby emulating the actual I^2t function..... Please share your comments on this..
@@sambenyaakov existing V. mode pwm usually have "peak" C.L. as a protection feature..this is on a pulse by pulse basis.....in an over current fault situation, where over an extended period of time..if this is active..the I^2t of the device or load may be still exceeded, eventually leading to some failure... therefore my reasoning is if such similar protection can be implemented in pwm control , with I(avg/rms)*√t.. , since I is in A/mA and t(on) is in uSecs. such may be easily done with transistor/opamp circuits..
Better than being electrified as I was as a kid🤣. You may be surprised, but many engineers think that a 1A fuse will blow at a little above 1A or that it can protect a MOSFET against overcurrent.
I have searched a lot about the concept of I2t and I didn’t understand. However, I understood now partially. I will watch your video again and again because I am slow learner. Thanks for the video.
Glad it was helpful!
I always pondered about modeling a thermal breaker or fuse using a single RC circuit like this and using a low-pass filter of current flow through a shunt and a comparater controlling a pass transistor to make an active fuse, though such chips already exist of course
Yes, ST just came out with a controller. But modeling is still important😊
Considering the case of open loop voltage mode PWM smps..the inverse...i.e. I (current) ×√time (in secs) (1000*1000u secs) can be implemented similarly for a
" pulse by pulse" protection thereby emulating the actual I^2t function.....
Please share your comments on this..
Thank you for comment, but I don't follow. Please eleborate.
@@sambenyaakov existing V. mode pwm usually have "peak" C.L. as a protection feature..this is on a pulse by pulse basis.....in an over current fault situation, where over an extended period of time..if this is active..the I^2t of the device or load may be still exceeded, eventually leading to some failure...
therefore my reasoning is if such similar protection can be implemented in pwm control , with I(avg/rms)*√t.. ,
since I is in A/mA and t(on) is in uSecs.
such may be easily done with transistor/opamp circuits..
Thank you for video. Very interesting and new stuff for me. I always wondered as a kid, why a 1A doesn't melt at 1A. felt like a scam 😂
Better than being electrified as I was as a kid🤣. You may be surprised, but many engineers think that a 1A fuse will blow at a little above 1A or that it can protect a MOSFET against overcurrent.
Thank you for the theory behind fuses. I have never looked into this. Your talk has inspired me to download and read the Kaufmann paper.
Thanks for sharing. The paper is old but still an eye opener.
thank you ❤
👍🙏❤️
🙏😊👍
great video! as always...
🙏🙂
Finally a good video regarding the melting integral I²t! Thanks Mr.Yaakov, again!
👍🙏
Thanks for your explanation
So nice of you. Thanks
Could you model the positive thermal coefficient of the fuse wire, I think the RT region could look like different @@sambenyaakov
It can be done by a variale resistor of course. Yes, it might change the shape. This is home work.