Flyback diodes, known by many names, prevent an inductive load (like a motor, such as a fan) from putting out "backwards" voltage to fry your circuit when it stops.
Cannot understand why you have only 195 views and only a couple of comments! Your explanation of the importance of placing a Flyback Diode in circuit was 10/10, and easily understood. You also mentioned that it was most important to place a Flyback Diode in any circuit which was transistor or MOSFET driven, such as a PWM Motor Controller. Use of the correct type (and rating) of the diode also plays a very important part in your explanation. Thanks for this information.
The reason why is because people have lived this long with it that they could actually live without acknowledging it in the instance it needs to be. Ive been going on car forums and being banned for being a spammer...Meanwhile ignorance in this instance isnt bliss its illiterate. I wonder how'd they feel knowing how this all transfers over to automobiles and why their cars are spending so much time in the shop and not seemingly to be properly fixed.. Thats Flyback causing those issues and gremlins and hiring an electrical engineer would reveal all the cars electrical systems weak points that need to be properly protected....
Thank you for this! Everywhere else they use a bunch of terms I don't know and turns out I don't need to know. This is easy to understand and you got dirrecty to the point. VERY helpful.
Damn dude: been looking to find a decent explanation on how flyback diode would work for an automotive relay: and I now totally get it :-) ... Many thanks ...
You should take this info and translate it to the components in your current automobiles and make the protections and notice the differences it makes when flyback isnt aggravating things...
Fantastic explanation, very useful for helping figure out how to wire up a diode to a 12v solenoid valve so that it doesn't blow up the smart switch turning it off and on.
You should take this info and translate it to the components in your current automobiles and make the protections and notice the differences it makes when flyback isnt aggravating things...
Some japanesse car makers wire main headlights so positive input is always on when the lights are off, then a ground connection is closed to turn them on. If you want to add a circuit with a relay to power on auxiliary lights when the high bean is switched on, then a flyback diode is required to avoid friying the main headlight bulbs when turning the high bean off. This video makes it easy to understand the reason for this diode in that specific scenario. Thank you for putting things so simple!
people will think the whiteboard is easy to write and erase, but there is a way of making symbols that can be taken and pasted on the whiteboard, I can easily understand by taking and placing the symbols used, thanks for the video
I've been watching so many tutorial about flyback, this video solves my problem. Because you explain the current direction of each state, most of the video I watch almost not showing the current direction
This is the best explanation I've found on RU-vid regarding flyback diodes. I've been browsing your videos and explanations and I really like them. I find it surprising you don't have more followers but you have a new subscriber in me. Looking forward to your content from now on.
The mark of a good tech video: 1) the presentation is easy to follow 2) the need is presented - "we need to protect circuit components from Back EMF" in this case 3) the footage is edited to get the point across instantly - not long-winded Just an excellent job. People loved my teaching (I taught STEM topics for 5 years at UCSC) because I knew the material as well as you know your material and wasted no time explaining things. I tell other people who would ask "why do you get such good reviews from students" 1) "You can explain something so that it can be understood" -- OR -- 2) "You can explain something *_so that it cannot be misunderstood_* Your communicating technique is (2), and it's the only way to win. By the way, in some cases, an MOV - "metal oxide varistor" - quenches the 'flyback' of Back EMF if the circuit has high current. Thank you kindly for an excellent easy-to-follow explanation! .
You should take this info and translate it to the components in your current automobiles and make the protections and notice the differences it makes when flyback isnt aggravating things...
I think I finally understand thank you. I always wondered why the diode was allowing flow from negative to positive. But as you explained the load has become the power supply the current is flowing in the original direction. Nice.
You should take this info and translate it to the components in your current automobiles and make the protections and notice the differences it makes when flyback isnt aggravating things...
Thank you! This was crystal clear, really the only video that made the idea pf flybacks clicl for me. You explain stuff really well, I enjoyed your video on decoupling caps too, and I can say that the circuit of the project I'm working on is much better because of your video. Thanks again, subscribed.
Finally I see the source of the nonsense about the infamous flyback diode. There is no flyback, no change in current direction, the current that built up the magnetic field in the inductor now wants to continue in the very same direction thru the inductor as that direction that created it. The magnetic field is now collapsing instead of being built and there is the only reversal applicable. In the twisted Franklin conventional current explanation you have to throw up a polarity swap to esplain it and that's where the flyback term comes in at. How droll, you'll get caught swapping polarities someday and it won't be pretty. But all the best anyway, I learned something fundamental today thanks to you.
At 47 seconds I subscribed 🍻💪 And what brought me here I like messing with electronics and I especially like making amplifiers I've run into a problem that I can now find cheap power supplies but they cause a terrible noise and I found that connecting an led to the positive leg of the transistor instead of a wire brings that signal to noise ratio almost to zero
So I'm hooking up a shaker motor to my virtual pinball cabinet and the guy (Major Frenchy) explaining how to properly wire it up just says put a diode on the motor. Doesn't explain why. He just says to wire it up and he actually tells you to do it the wrong direction, negative to the positive post and vice versa. "What!?" I proclaim, "How can this be? What does it do? Why is it like that?". Well that's how I got here. Thanks for explaining it!
You should take this info and translate it to the components in your current automobiles and make the protections and notice the differences it makes when flyback isnt aggravating things...
theres also an important series diode required when high side switching inductive loads... if the ground end is clamped to ground, the freewheel diode is indeed, freewheeling the collapsing field in the coil. but if the grounded end is grounded and cant go positive..? the high side has to go negative... _below_ ground. and that, depending on the driver used, can be a bit of an issue...
Thanks for the video ......I'm having a diode problem .....I'm using a PMDC motor as an assist on my velomobile , the recumbent trike has PV 150 watts mounted on the trike . I'm not using a speed controller on the motor because it's geared so low that I'm doing walking speed with just the motor . The motor is chained to a bicycle fixed chain ring , the velo and trailer are at about 600 lb , so I use regerative braking a lot . I use a diode at the positive output of the motor to the batt and a relay as a switch . When I close the circuit the motor turn on , which I use going up hill , on the level the motor becomes a generator if I pedal ( one of the trike wheel is a 8 speed internal geared rear hub) I'm putting some current to the battery and when going down hill it's a generator. Now here's my problem when going downhill I can see the voltage augmenting but the regerating is not very strong thru the diode and when I close the switch the trikes slows down with more force ..........My question is why is the diode acting with less resistance than the closed switch....thanks for your time and a will install a diode aas you showed
Had a blower motor that would stay running after you switch it off. Couldn’t understand how a bad diode in the circuit could backfeed to the switch, to keep power supplied to the motor. But your explanation helps with you saying it could actually jump the contacts of the switch if it backfeeds
You should take this info and translate it to the components in your current automobiles and make the protections and notice the differences it makes when flyback isnt aggravating things...
Well done video. You need to make one on all the relays,switches and solenoids with-in one vehicle thats unprotected and how it needs to be properly protected. That information would be priceless to the consumer and would make them smarter than the average mechanic. Im an auto tech but I also have backgrounds in building firing solution boxes for the apache helicopter and I also worked in microwave communications also micro robotics. I also debunked the mystery as to why TFI modules truly burn out too which is Flyback..I knew this 16yrs ago when a ford tech that was retired revealed it but didnt state why but rehashed it when I had an old ECU repaired to sell and the repair guy said my ecu was bombarded by heavy Flyback..
interesting about the TFI modules ... i started thinking about that when this topic came up .. im assuming it wasnt ignition coil flyback voltage that kills the modules, as that is obvious and surely the engineers would have provided protection against that.. so where is the vulnerability of the TFI and to what actually causes them to die so frequently?
Great explanation. As you explained this great I'm wondering if you can maybe do a video or advise on the second issue with this, which is sparking across the switch/Relay. For example If you need the switch / Relay to power a, few sensitive electronics with other loads - ie low voltage mcus ssds etc as well as other loads, how would you protect this switch /Relay from sparking?
Hi, great explanation! However I believe there's a little clarification to be made: at 5:40 you said we could use multiple diodes in parallel but that is not actually theoretically feasible, diodes (and all semiconductor based components I believe) have a positive temperature coefficient (don't quote me on that, there must be an appropriate name I'm missing), meaning the more a diode heats up the more it gets conductive (due to increased electron-hole couples). The current will be higher on the most conductive diode (diodes will inevitably have very small differences) thus heating it up and making it more conductive again, it's a dog biting its tail sort of thing; given an infinite time (and not considering the component would melt or loose semiconductor properties anyway) current will eventually flow through only one, extremely hot and conductive, diode. If you would want to use this configuration you should put both resistors and diodes in parallel, using the resistor (which btw have a negative temperature/conductivity coefficient so no problem there, current will balance between component) to force a specific amount of current to each diode. Realistically in this case the flyback effect doesn't endure enough time to even see any difference in diode imbalances, so you are absolutely right: multiple diodes would do the trick. Thanks again for the video!
I recently learned about what you describe when researching using multiple transistors in parallel, but I'm not sure what you say applies here, because the diodes are going to be all at ambient temperature before the current surges through them, and the current will be extremely short lived. Unless the load is being rapidly pulsed on and off, of course. So I think it would still work fine to handle the very start of the surge, and even if the diodes managed to heat up at all, even the act of them heating up would have dissipated a bunch of the energy so being more conductive when there's less to conduct will still work.
@@simplyput2796 yes, exactely like you said! it would work totally fine since the current passing though the diodes is very short lived; I just wanted to point out that diodes (and transistors as you cofirmed me) can't be used in constant parallel configuration as we would normally do in resistors. It often sucks since we're forced to buy very speficic semiconductive components even for basic circuits. Have a nice day!
Nice job ...does the reverse voltage breakdown that makes the diode to conduct , have any impact in selecting the diode ratings to used across a coil ? If it does , how do you now determine the diode to used if , for instance the supply Voltage is 24vDC ?
Thanks - I think I might've got it! I was struggling with that second -neg terminal on the inductor demanding current when the neg terminal on the original psu is still there and grounded (usually shown as).
You should take this info and translate it to the components in your current automobiles and make the protections and notice the differences it makes when flyback isnt aggravating things...
two questions in the diagram feasibility. 1st ,i s flyback always active at on and off state (unless you put resistor before diode it seemed i flows both ways )? and also can we use Zenior diode in place of flyback ( let me know if not y ? I thoght for protection of high voltage zenior is good enough ) ? many thanks !
cant you just put the switch after the inductor component and add a capacitor to the power supply in case of it being a battery to suck up the reverse voltage?
One question.. say the power source is a battery, that I'd like to charge using the fan. I want the positive output to go to the negative on the battery, correct? If so, how could this be accomplished without creating a bridge that allows the battery to flow back to it's self without powering the fan?
Hi as you know sometimes we have a reverse voltage in pulses for example in diodes we have a reverse recovery time in diodes that makes small amounts of negative voltage ....i have this issue..my pulse drived an adc and this reverse Voltage can damage my adc and because my signal is 1ns in pulse width icant use buffer ic how can I remove this negative Voltage of my strobe pulses?
DC motors operate by constantly turning on and off the coils within. Isn't it true then that the negative voltage developed multiple times per revolution of the motor?
