“This is the current being interrupted but . . .” This is ‘when’ the current being interrupted but . . . 1.3 Henrys :o Lower the ‘vertical’ sensitivity.

The local supply bypass capacitor needs to connect from the coil supply to the FET source and the diode directly from the coil supply to the FET drain. This constrains the switching transient within the triangle of those three components. Of course. [image] Paul_B: As I indeed explained - bu…

[image] JohnRob: [image] Paul_B: As I indeed explained - but a much larger capacitor is needed - in my original discussion. :grin: I believe you stated, not explained. Can you put some numbers to your claim? Well, we use 0.1 µF for logic circuits where the commutation currents are in t…

[image] Paul_B: least 10 µF but 100 or 220 µF intuitively sounds no numeric examples? What about the resonant frequency of the 100 to 220 (presumably) aluminum electrolytics?

David Jones has recently put up a good video at EEVBlog on some pitfalls of omitting a free-wheel diode (including unintended RF transmission risk): https://www.youtube.com/watch?v=hReCPMIcLHg

[image] JohnRob: no numeric examples? What about the resonant frequency of the 100 to 220 (presumably) aluminum electrolytics? I have avoided discussing angels as per #50. :grin:

Everyone here agrees a diode (or somethig else to dissipate the energy) is needed. Your explanation why it is needed is nice. However most of this discussion is about where to place this diode. I think it was already exhausted by reply #5. The fact a guy claims NASA wants diode at each inductor prov…

[image] Seriously though..... I think the "discussion" phase of this thread has been beat beyond death, so I will not try to explain why I believe the diode must be at the source. The only way this will be resolved (if that is possible) is to build a circuit and measure the results. Alternately…

Perry, sent this on this thread as the new flyback sticky post is locked. it would be informative to use the data sheet schematic of a TIP120 or some such to show the diode. and then put that into the schematic you have on the flyback post. since it is not across the coil, it is not going to ach…

Hi Dave, I'm not at all clear what you are asking me to do, the TIP120 is a Darlington transistor as far as know, I don't see the relevance. The core purpose of the tutorial was that I had noticed that people were being told they needed a flyback diode but often there was little or no justificatio…

Im thinking how to use. To to clarify the use was my point. Once in awhile there are discussions that you need a diode . And chip so-and-so has a diode

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