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....
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.
This is the best explanation I've found on TH-cam 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.
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...
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...
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
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! .
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!
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
The one fact you failed to mention is this: When you open a switch on a motor or any inductive load, the magnetic field collapses very quickly and the voltage it produces in the opposite direction can be 10 times or even 100 times higher than the voltage supplied to the inductor and this is why the spark across an opening switch is much higher than the any spark produced when you close a switch.
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.
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...
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?
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!
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
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?
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 for the video. Presumably the diode would cause some resistance, and you note that current would go across the resistor (or wiring resistance it would seem) to the negative power supply. Wouldn't the main reason current doesn't go back to the power supply be because that part of the system is not actually a complete circuit at that point?
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 - 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...
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...
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!
One question: can you tell us how we should choose the diode? Should it be a schottky or regular one? What are the characteristics we should consider when choosing the correct diode for the job? For instance, I have a 5v waterpump drawing 220mA, maybe a flyback is not needed for this low power circuit, but what would I need there? Thanks!!
You're probably better off looking for real engineering documentation for this information (like EEVblog), because I'm just explaining the concept and I'm not actually an engineer, but I'll give you my best advice. First, I would use a strong regular diode, like one that's designed to be used in a rectifier, because your circuitry is unlikely to be damaged by having a diode drop's worth of wrong voltage going through it, and you want one that can dissipate a lot of power without breaking. You could add a resistor in series with the diode to help protect the diode, but that will reduce the response time of the diode's protection. My recommendation is always to just test it using parts you can afford to lose (the inductive load won't be hurt by the back-emf, so just the rest of it needs to be replaceable). Put together a mock-up circuit with your inductive load in it, and hammer it, checking to see if the diode breaks or gets warm. If it stays cool, you don't need anything else.
Let's say I am wanting to build an automated greenhouse with water pumps, fans, and servos for opening air vents: is a flyback diode going to need to be implemented for all those components? How do you calculate the the type of diode you would need for each component or does it matter?
I would honestly recommend looking in the technical documentation you get with each of those motors and with the transistors or relays, because I can speak only generally that inductive loads create an EMF when turned off. How strong it is and if it's actually dangerous depends on the circuit paths and components involved, and whether you need a simple schottkey diode to quickly shunt and then stop, or you need something beefier possibly paired with a small resistor, depends on the EMF strength. I would imagine that your parts will tell you what you need or should have, as long as you're not getting cheap Chinese junk.
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 !
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?
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....
He does deal with it very well !
Forget about the phrase eye-openner. This is mind-openner.
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 are very good at explaining things clearly. Thank you ❤️
This is the best explanation I've found on TH-cam 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.
It's because I post videos so irregularly, TH-cam doesn't recommend my videos too much. I need to get better at time management!
5 years later and this is still the first source that has helped me actually understand what a fly back diode does
Explained simply and brilliantly. I swear this isn't backhanded: your presentation-personality is perfect. Thank you for putting this out there!
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...
SImple and to the point. Thank you. My only regret is that I didn't have this guy as my teacher in college.✌
Incredibly well explained. Thank you so much for the explanation. You have a new fan.
Thanks mate, very well explained. Love the current direction and voltage terminal magnates.
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...
you explaned this better than ANYBODY! thank you!
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...
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
Thank you for such a great summary of protecting circuits with flyback diodes. Much appreciated.
Great video! You did explain that in a very unconfusing way unlike other sources. I got it now after I smoked more than half of my mosfets...
your presentation about the circuit was very fun to watch. it looks very clean and satisfying
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!
.
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!
Best explanation and thought process of diodes I've ever seen!
Best spent 8 minutes and 25 seconds of my day
You've got a talent .... never understood this concept until watching your explanation !!
Thank you! The explanation of the backwards connection of the diode finally makes sense to me.
Your videos are extremely well done. Thank you so much. You make learning electricity much more fun and much easier.
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
By far, the best explanantion I've seen
Very well explained.
Thanks a lot.
The one fact you failed to mention is this:
When you open a switch on a motor or any inductive load, the magnetic field collapses very quickly and the voltage it produces in the opposite direction can be 10 times or even 100 times higher than the voltage supplied to the inductor and this is why the spark across an opening switch is much higher than the any spark produced when you close a switch.
Yeah this is the best video on the subject. Please continue to make more!! Thank you!
What a great video good work mate 👍thanks for sharing
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.
exhaustive and very clear in the explanation ... thank you very much
Thanks for your excellent explanation.
Brilliant explanation! Thank you!
Such a great explanation
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.
You, sir, are just amazing.
Thank you for sharing this very useful information. Great explanation!!!
thank you for taking time to explain it this way
thank so much for making this so easy to understand !
Best explanation yet, many thanks!!
Such a great video man. Thank you!
Superb explanation
Excellent explanation. Thank you
Brilliant, truly simply put!
Excellent explanation, I finally learned something fast, thank you 👍!!
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...
Great explanation.
Great video 👍🏻
Subscribed and liked, dude you deserve millions of views!
As always, incredible..
Very clear explanation.
I feel like I'm going to be coming back to this channel
Amazing - thanks for your videos :)
Mega thanks for this explanation!
Great explanation! Well-done I'm subbing!
This is an excellent explanatory video. I totally get it! This needs to be up voted somehow.
Well explained...thank you sir!
Simply put, you are simply amazing
Thanks very good explanation!
Very helpful, thank you very much!
Grate ,Nice explanation
Thank you so much, This is very useful information Sir.
Thanks great explanation 👍
THANK YOU!!! Truly - "Simply put", yet thorough. (I prefer your name for it also,"anti back-flow diode, ABF diode or ABD).
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?
Thank you, this helped me a lot!
Very well explained
super explanation. thanks a bunch.
Really clear, thank you
Awesome... easily explained 🎉
thanks a lot, that was a great explanation!
definitely SIMPLY PUT!! Thank 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!
this is great, thanks!!!
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
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?
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 for the video. Presumably the diode would cause some resistance, and you note that current would go across the resistor (or wiring resistance it would seem) to the negative power supply.
Wouldn't the main reason current doesn't go back to the power supply be because that part of the system is not actually a complete circuit at that point?
Thank you for the video. I get it now. Awesome! :)
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 - 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...
thank you.
Thanks Hagrid 😘
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...
thank u!
3:53 Reminds me of that Crash Test Dummies song
GOD SHUFFLED HIS FEET....... THEN GOT AN ELECTRIC SHOCK
Thanks
If you had a few inductors in series or parallel, would you use a proper amp rating, flyback diode across each inductor, or only across Vin and Vout?
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!
One question: can you tell us how we should choose the diode? Should it be a schottky or regular one? What are the characteristics we should consider when choosing the correct diode for the job? For instance, I have a 5v waterpump drawing 220mA, maybe a flyback is not needed for this low power circuit, but what would I need there? Thanks!!
You're probably better off looking for real engineering documentation for this information (like EEVblog), because I'm just explaining the concept and I'm not actually an engineer, but I'll give you my best advice. First, I would use a strong regular diode, like one that's designed to be used in a rectifier, because your circuitry is unlikely to be damaged by having a diode drop's worth of wrong voltage going through it, and you want one that can dissipate a lot of power without breaking. You could add a resistor in series with the diode to help protect the diode, but that will reduce the response time of the diode's protection. My recommendation is always to just test it using parts you can afford to lose (the inductive load won't be hurt by the back-emf, so just the rest of it needs to be replaceable). Put together a mock-up circuit with your inductive load in it, and hammer it, checking to see if the diode breaks or gets warm. If it stays cool, you don't need anything else.
Perfect 👌🏽
You the man
Let's say I am wanting to build an automated greenhouse with water pumps, fans, and servos for opening air vents: is a flyback diode going to need to be implemented for all those components? How do you calculate the the type of diode you would need for each component or does it matter?
I would honestly recommend looking in the technical documentation you get with each of those motors and with the transistors or relays, because I can speak only generally that inductive loads create an EMF when turned off. How strong it is and if it's actually dangerous depends on the circuit paths and components involved, and whether you need a simple schottkey diode to quickly shunt and then stop, or you need something beefier possibly paired with a small resistor, depends on the EMF strength. I would imagine that your parts will tell you what you need or should have, as long as you're not getting cheap Chinese junk.
Great video, thanks. Anyone know if this would work on an AC motor, and should I do this on my 12volt 15amp AC motor?
this was good
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 !
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?
Will this work if, say, you have two fans that are in parallel?
The resistor should be before the fan right???