A very well done demo of why a diode is required to direct a collapsing magnetic field to prevent circuit damage. The use of LEDs to make your point was genius.
@William Custinne That's a good idea for teaching students, Once they get that shock, they will never ever forget to put that diode in this relay circuit in future. :)
In the (g)olden days before transistors, relays and switches controlled everything, and "low voltage" control was often 24VAC, sometimes rectified to 12V with a bridge. With nothing installed across the coils of the relays, switches contacts would become welded shut from the back EMF. Initially caps were used to shut the back current, but when the price of diodes came down they became the standard
There is a trend in higher current relays with DC loads to use a zener diode in series (opposite polarity) with this diode to collapse the field. It still protects the driver but it collapses the field faster by having a higher clamp voltage. Still safe, maybe between 10 and 40 volts, with a driver rated higher than this. This arrangement opens up the contact faster and offers longer contact life and a lower chance of contact welding which can be a problem in higher current loads and relays, especially with DC relays and loads like the ones used to run car cooling fans. With a simple diode clamp, usually AC loads are fine but a DC load with inductance can arc, welding the contact on if the contacts don’t move away from each other fast enough.
I used to see buckets of relays welded shut that my dad collected from HVAC work. It is cools to now understand what was happening. I also remember these big capacitors we would add to struggling systems to help with compressor and fan motor load fluctuations. The were really simple back then.
This is the basis of boost converters, having the inductor increase the voltage. The down side is a diode slows down the relay opening by two to three times allowing more arcing of the relays contacts. Since you only need to protect the switching device, a resistor can be placed in series with said diode to increase the clamping voltage or a zener. RC networks can also be effective.
Yeah. Some years ago I bought a 12V mini-UPS device, and noticed it had a standard 3.7V Li-ion battery inside, yet was able to output the required 12V. I obviously needed to learn how such a thing is achieved, and thus learned about the fascinating theory behind the step-up converters.
@Michael David Robinson the pilot If you select the correct diode and resistor the failure rate is infinitesimal, therefore no need for a duplicate. The use of the highest voltage diode, as you mention 4007 that is ok and cheap, try a 1k resistor and then go to a 250ohm, to notice the difference. The problem is each type of relay is different, number of turns on the coli, the amount of flux stored in the core, etc. Each needs to be tuned.
The diode provides a path for back EMF current to flow delaying release of the relay. For high speed relays, sometimes a resistor of the same resistance of the coil results in decay times = to the attack rate. On release the emf voltage is the same as the applied voltage was, so no damaging spike. Sometimes a zener diode is used instead of the resistor. This is sometimes used in protection circuits for fast response. The string of LED's in the video dissipate the coil energy quicker than the shunt diode as the higher reverse voltage changes the current quicker. This can be seen on a scope. For most applications just the diode for protection is required.
This is known as flywheel diode. It provides and easy path to the current which is produced due to back emf. Without this diode the current due to back emf can easily destroy the switch activating the relay.
The current is kept flowing by the collapsing magnetic field,if there is no path for that current to flow in then the voltage across the coil will peak at about 7X.
The main purpose of diode in this connection is to protect additional circuits/power source. We connect diode in parallel connection on this relay coil (Anode to -volts ; Kathode to +volts) in this set up the diode is inactive, {it doesn't affected by the inputvolts/12v}. But right after you cut the power in the coil, this coil generate Back EMF volts in opposite direction > "Anode to (+) ; Kathode to (-)" this voltage polarity activates the diode and in this circuit the diode acts like a wire to short circuit the back EMF. But if you connect diode (Anode to +volts ; Kathode to -volts) in parallel correspond to the load at first, this diode will initially be activated {and is affected by 12v} this diode will short circuit the connection and current will not be able to flow in the load/coil. # We can't use LED/resistor as circuit protector, (it won't fully absorb the back emf) and it can't fully protect the circuit . # The major part of a relay is a Coil, This Coil acts like an inductor (inductor can generate very high voltage or "Back EMF" [current x resistance = Back EMF volts]) that relay coil has the ability to generate thousand of volts and it can cause a considerable damage in your circuit. "this is why we must provide a path for the back EMF/current to flow".
In addition to being called a flyback diode circuit, it is also known by many other names as well: *Snubber circuit, *Clamping circuit, *Suppression circuit, *Protection circuit
@Y B , you are 100% correct. However, I have seen the term "snubber" used to describe circuits that utilize resistor-capacitor (RC), as you say, in addition to diode only and resistor-capacitor-diode (RCD) circuit designs.
very useful, thanks. how do we know what diode do we need there? since, for example, for a fan we need very much amps? what kind of diode should we use if there's a 500A draw?
I've explained back EMF to many people but showing in this manner is a great idea. I will help greatly seeing with their own eyes then just trying to imagine it in their heads.
I usually prefer videos with actual voices explaining what is going on. But your visuals with the LEDs works even better for a novice like me. Now I REALLY understand. Thank you.
When I wired this up to test it I noticed that the LED pulses faintly sometimes when the switch is closed as well as when it opens again. I suppose this could be due to the contacts in the switch occasionally bouncing when it is pressed.
All our DC relays have flyback diodes. That’s what we call them. The term normally applies to cathode ray tubes (CRTs) but we use the term for this application, too.
A snubber is a device used to suppress "snub" the “inductive flybackback” from motors, solenoids, relay coils, or any electromagnetic device energized with an inductive load is abruptly interrupted (switched off). When the flow of current is suddenly eliminated, A sharp rise in voltage across the switching contacts polls can create a high voltage electrical spike within the device. If this voltage spike is higher than what the internal electronic components can tolerate, (max voltage rating) permanent damage may result. However, that's not all... The sudden power interruption can also create electromagnetic interference (EMI) pulses that can affect other electronic devices within close proximity. These transients (noise) sometimes produced clicks that can be heard through radios, TVs, amp speakers, etc. Snubber circuits are use to minimize these situations by providing an alternative current discharged path away from the coil or switch that can produce these phenomena.
Thanks, I've been reading about this, helps to see a definitive real world example. Wondering if there is still enough to power the original single LED
What about the use of a double-pole switch, which also breaks the circuit between the sensitive load (your five LEDs) to prevent any back-emf from damaging a switching transistor or similar?? In this way, there would not be a voltage drop across the relay.
@ Tech Ideas Can you suggest 5 volt ac supply relay for activating the relay coil and common pin should be able to handled 12 to 30 DC voltage with around 5 to 10 amperes ?
Makes the point quite well, thank you. One thing I don't get though is how the diode helps relative to its direction. So when the backfeeding happens current flows essentially from "negative to positive leads of the circuit", which is why the LED lights up (anode is on the negative side, cathode on the positive side). But the regular diode is wired in parallel to that with the same anode/cathode arrangement. So I don't get how it helps - isn't it allowing current to flow the same direction as-is powering the LED's? Both are allowing current to flow towards the positive wire towards the switch, no? I'm missing something.
Why don't the LEDs light up when still connected in parallel with the diode. I understand the diode stops current from negative to positive but why doesnt it still flow through the LEDs?
I can't fathom why this has over 500+ thumbs down. You couldn't describe the issue any better. Thanks for the technical help, this really clears up a lot for me.
Since the led and the diode are connected in parallel so the reverse voltage choose to be short by the diode. I would assume it would flow through both but half and half?
I have 0 knowledge of electronics and I have to say: your explanation is very clear. Since this seems to be a well known issue, shouldn't all relays come with a diode to prevent reverse current from damaging the relay or the circuit? (I have a wine fridge PCB to trouble shoot and I think I have relay issues... ;))
Very correct demo. While switching off collapsing field develops high emf which can damage semiconductor components connected to relay. Video appreciated.
The direct answer to the question in the title of course can be very brief ....... but you made it very visible to those that think it's not so bad to leave it out
Can you please show how to use the diode when working with 5v 4 channel relay module and operating electrical appliances. I just damaged 2 relays and I think the reason is reverse charge.
Most of the designers use for home use diode on the relay coil.it is better to add a resistor instead of relay or to add a resistor with a series zenner diode. Have a look on a relay datasheet especially for higher grade application (automotive,military and aviation) The reason for not using diode is that by using it you short the coil induced voltage to a 0.6v and this will be translated in slower operation of the relay and will decrease the lifecycle guaranteed by producer . By using resistor you need to calculate more the max voltage that is allowed on the driver transistor.
Hi I 've used solid state relay for my car dome light trigger, as we know car dome light is negative trigger. so I connect pin 3 to continuous +12v and pin 4 to switched ground negative. When the pin 4 swithed to ground the relay work as expected it joint/closed pin 1 and 2, however once the pin 4 ground is switched off the relay is still closed. Any explanation or solution to this issue ?
Hello, great video 😄 I'm a beginner and I have a question : Is it absolutely mandatory to put a protection diod in parallel with a relay? Thank you in advance 😉. Cordially.
I'm using 12v relay in my project....I used diode 1N4007,...With 230v ac power supply... When relay gets off my 16*2 LCD display shows unknown characters.. How to solve this problem... Plzzz
i don’t understand . can i use a and 2v Led red light instead of a 0.7V diode? besides, why a 0.7v diode can withstand a reverse voltage which is more than 10 v.
How can I connect led lights in my car to come on when I unlock the car with my dome light and also be able to turn on with the fog lights as well?? ..... HELP!! 😩
Thank you. Have you considering a remake of this video with a theoretical explanation of the field in inductor. It would make it one of the best videos on this topic!
simply, the magnetic field in the coil collapses when current is interrupted. That generates a current in the same direction as the original current. When you put a diode in reverse polarity across the coil of the relay it allows the current to flow from the output of the coil back to the input with very little voltage out of the coil(that voltage which forward biases the diode). When you put the string of LEDs as the conduction path from the output of the coil back to the input no current will flow until the collapsing field generates a high enough voltage to forward bias the diodes. So, the collapsing field will rapidly rise to the voltage needed to maintain the current which was flowing before the switch was interrupted, until all the coil's energy is dissipated. The most interesting thing about the coil(almost like there was some intelligence built into the coil) is that inductors are volt-second device, that is the output volts X time is equal to the input volts X time. So if you put 9 volts for 1 second into the coil you get 9 volt-seconds out of the coil. If you put a bunch of diodes in the feedback path(or flyback as it is usually called) voltage will have to rise higher to make the coil conduct. For example, if the output voltage has to rise to 27 volts to conduct, then the conduction time will be 1/3 of a second(27v X 1/3 second = 9 volt-seconds).
Sir I making blinking ckt with 555 ic timer &one take chargeable china torch light open the torch & saprate connect the blinking ckt parallel to inside the toch light , the the lights blinking after one hour not blinking & not change battery. what will be mistake ,where the connect diode.
2:38 why these red LEDs are not glowing when you on switch electrons can flow easily so explain me and why it is glowing in reverse voltage why not in forward voltage tell 🙏
You should do a follow-up video to show why diode protection aswell as diode protected relays and starter solenoids everywhere important in automobiles as this is why most vehicles on the road are failing with faulty switch panels broken climate control plus even burnt out sensors and engine computers plus transmission changes/overhauls. Even fuel injectors should be manufactured with built-in flyback protection..
A very well done demo of why a diode is required to direct a collapsing magnetic field to prevent circuit damage. The use of LEDs to make your point was genius.
Thanks
Nice demo of the relay coil's inductance, and the importance of a diode across the coil to dampen the jolt.. Great job.
you kidding dude ? genius
@William Custinne That's a good idea for teaching students, Once they get that shock, they will never ever forget to put that diode in this relay circuit in future. :)
Loved this 👍🏽👍🏽👍🏽
In the (g)olden days before transistors, relays and switches controlled everything, and "low voltage" control was often 24VAC, sometimes rectified to 12V with a bridge. With nothing installed across the coils of the relays, switches contacts would become welded shut from the back EMF. Initially caps were used to shut the back current, but when the price of diodes came down they became the standard
There is a trend in higher current relays with DC loads to use a zener diode in series (opposite polarity) with this diode to collapse the field. It still protects the driver but it collapses the field faster by having a higher clamp voltage. Still safe, maybe between 10 and 40 volts, with a driver rated higher than this. This arrangement opens up the contact faster and offers longer contact life and a lower chance of contact welding which can be a problem in higher current loads and relays, especially with DC relays and loads like the ones used to run car cooling fans. With a simple diode clamp, usually AC loads are fine but a DC load with inductance can arc, welding the contact on if the contacts don’t move away from each other fast enough.
I used to see buckets of relays welded shut that my dad collected from HVAC work. It is cools to now understand what was happening. I also remember these big capacitors we would add to struggling systems to help with compressor and fan motor load fluctuations. The were really simple back then.
This is the basis of boost converters, having the inductor increase the voltage. The down side is a diode slows down the relay opening by two to three times allowing more arcing of the relays contacts. Since you only need to protect the switching device, a resistor can be placed in series with said diode to increase the clamping voltage or a zener. RC networks can also be effective.
Yes - I think the zener is the best solution as, correctly chosen, it gives the fastest relay response for a given permitted inductive spike voltage.
Yeah. Some years ago I bought a 12V mini-UPS device, and noticed it had a standard 3.7V Li-ion battery inside, yet was able to output the required 12V. I obviously needed to learn how such a thing is achieved, and thus learned about the fascinating theory behind the step-up converters.
@Michael David Robinson the pilot If you select the correct diode and resistor the failure rate is infinitesimal, therefore no need for a duplicate.
The use of the highest voltage diode, as you mention 4007 that is ok and cheap, try a 1k resistor and then go to a 250ohm, to notice the difference.
The problem is each type of relay is different, number of turns on the coli, the amount of flux stored in the core, etc. Each needs to be tuned.
Oh, i was working on access door system before and i found this diod and didn't know what it's for.
Thanks a lot.
The diode provides a path for back EMF current to flow delaying release of the relay. For high speed relays, sometimes a resistor of the same resistance of the coil results in decay times = to the attack rate. On release the emf voltage is the same as the applied voltage was, so no damaging spike. Sometimes a zener diode is used instead of the resistor. This is sometimes used in protection circuits for fast response. The string of LED's in the video dissipate the coil energy quicker than the shunt diode as the higher reverse voltage changes the current quicker. This can be seen on a scope. For most applications just the diode for protection is required.
It was also added to prevent what used to be called relay chatter. Had to do with voltage on the coil.
Thank you, it’s a very good graphical way to explain it.
+Javier Garcia Alvarez
Thank you
This is known as flywheel diode. It provides and easy path to the current which is produced due to back emf. Without this diode the current due to back emf can easily destroy the switch activating the relay.
The Engineer back emf ???
you mean flyback
Yes Back EMF
The current is kept flowing by the collapsing magnetic field,if there is no path for that current to flow in then the voltage across the coil will peak at about 7X.
Not Bemf, but self induction
Hadn’t realised that at all. Very clever way to show it. Very clear. 👍🙂🏴
EXCELLENT practical example to visually demonstrate the need and use of a "Flyback Diode".
Thank you for sharing, great video!
Great video! I want to start experimenting with computer controlled circuits using relays, and this was very helpful.
Thank you
Well done. Exactly the info I needed.
The main purpose of diode in this connection is to protect additional circuits/power source.
We connect diode in parallel connection on this relay coil (Anode to -volts ; Kathode to +volts) in this set up the diode is inactive, {it doesn't affected by the inputvolts/12v}. But right after you cut the power in the coil, this coil generate Back EMF volts in opposite direction > "Anode to (+) ; Kathode to (-)" this voltage polarity activates the diode and in this circuit the diode acts like a wire to short circuit the back EMF.
But if you connect diode (Anode to +volts ; Kathode to -volts) in parallel correspond to the load at first, this diode will initially be activated {and is affected by 12v} this diode will short circuit the connection and current will not be able to flow in the load/coil.
# We can't use LED/resistor as circuit protector, (it won't fully absorb the back emf) and it can't fully protect the circuit .
# The major part of a relay is a Coil, This Coil acts like an inductor
(inductor can generate very high voltage or "Back EMF" [current x resistance = Back EMF volts])
that relay coil has the ability to generate thousand of volts and it can cause a considerable damage in your circuit.
"this is why we must provide a path for the back EMF/current to flow".
Jhovanie Benliro ooooh
Thank u
You are nice man
In addition to being called a flyback diode circuit, it is also known by many other names as well:
*Snubber circuit, *Clamping circuit, *Suppression circuit, *Protection circuit
@Y B , you are 100% correct. However, I have seen the term "snubber" used to describe circuits that utilize resistor-capacitor (RC), as you say, in addition to diode only and resistor-capacitor-diode (RCD) circuit designs.
very useful, thanks. how do we know what diode do we need there? since, for example, for a fan we need very much amps? what kind of diode should we use if there's a 500A draw?
I've explained back EMF to many people but showing in this manner is a great idea. I will help greatly seeing with their own eyes then just trying to imagine it in their heads.
Thank you
Clever! You did very nice, clearly demonstrativ job. No words at all, but worth than 1000000 words. Keep doing it.
I usually prefer videos with actual voices explaining what is going on. But your visuals with the LEDs works even better for a novice like me. Now I REALLY understand. Thank you.
Thank you
Great explanation!!! Thank you!
When I wired this up to test it I noticed that the LED pulses faintly sometimes when the switch is closed as well as when it opens again. I suppose this could be due to the contacts in the switch occasionally bouncing when it is pressed.
All our DC relays have flyback diodes. That’s what we call them. The term normally applies to cathode ray tubes (CRTs) but we use the term for this application, too.
A snubber is a device used to suppress "snub" the “inductive flybackback” from motors, solenoids, relay coils, or any electromagnetic device energized with an inductive load is abruptly interrupted (switched off). When the flow of current is suddenly eliminated, A sharp rise in voltage across the switching contacts polls can create a high voltage electrical spike within the device. If this voltage spike is higher than what the internal electronic components can tolerate, (max voltage rating) permanent damage may result.
However, that's not all... The sudden power interruption can also create electromagnetic interference (EMI) pulses that can affect other electronic devices within close proximity. These transients (noise) sometimes produced clicks that can be heard through radios, TVs, amp speakers, etc.
Snubber circuits are use to minimize these situations by providing an alternative current discharged path away from the coil or switch that can produce these phenomena.
Awesome project. Very helpful.
Should also talk and explain about the things he is doing. Thanks for hardworking
Thanks, I've been reading about this, helps to see a definitive real world example.
Wondering if there is still enough to power the original single LED
I always wondered why a diode was required. What rated/type of diode would I need for a 5v and a 12v circuit?
What about the use of a double-pole switch, which also breaks the circuit between the sensitive load (your five LEDs) to prevent any back-emf from damaging a switching transistor or similar?? In this way, there would not be a voltage drop across the relay.
I'm so glad I found this video thanks for sharing 👍👍👍👍👍
@ Tech Ideas
Can you suggest 5 volt ac supply relay for activating the relay coil and common pin should be able to handled 12 to 30 DC voltage with around 5 to 10 amperes ?
simple!!! this is for voltage spike like -300v to -400v at tiny little amp which also kill you another sensitive electronic component
Very very very very cool way to explain. Thanks
Makes the point quite well, thank you.
One thing I don't get though is how the diode helps relative to its direction. So when the backfeeding happens current flows essentially from "negative to positive leads of the circuit", which is why the LED lights up (anode is on the negative side, cathode on the positive side). But the regular diode is wired in parallel to that with the same anode/cathode arrangement. So I don't get how it helps - isn't it allowing current to flow the same direction as-is powering the LED's? Both are allowing current to flow towards the positive wire towards the switch, no? I'm missing something.
Why don't the LEDs light up when still connected in parallel with the diode. I understand the diode stops current from negative to positive but why doesnt it still flow through the LEDs?
I can't fathom why this has over 500+ thumbs down. You couldn't describe the issue any better. Thanks for the technical help, this really clears up a lot for me.
Thank you
Since the led and the diode are connected in parallel so the reverse voltage choose to be short by the diode. I would assume it would flow through both but half and half?
I have 0 knowledge of electronics and I have to say: your explanation is very clear. Since this seems to be a well known issue, shouldn't all relays come with a diode to prevent reverse current from damaging the relay or the circuit? (I have a wine fridge PCB to trouble shoot and I think I have relay issues... ;))
Great demo!
Thank you
We can avoid this problem through a diode(1N4001/7) ..it is called free wheel or fly back diode
Very correct demo. While switching off collapsing field develops high emf which can damage semiconductor components connected to relay. Video appreciated.
Thank you
just beautiful !!!
The direct answer to the question in the title of course can be very brief ....... but you made it very visible to those that think it's not so bad to leave it out
Good video. Explained well.
Good information through simple explanation.
Can you please show how to use the diode when working with 5v 4 channel relay module and operating electrical appliances. I just damaged 2 relays and I think the reason is reverse charge.
Very well explanation bro thank you!
Most of the designers use for home use diode on the relay coil.it is better to add a resistor instead of relay or to add a resistor with a series zenner diode. Have a look on a relay datasheet especially for higher grade application (automotive,military and aviation)
The reason for not using diode is that by using it you short the coil induced voltage to a 0.6v and this will be translated in slower operation of the relay and will decrease the lifecycle guaranteed by producer .
By using resistor you need to calculate more the max voltage that is allowed on the driver transistor.
Very helpful.
Thank You.
Hi I 've used solid state relay for my car dome light trigger, as we know car dome light is negative trigger. so I connect pin 3 to continuous +12v and pin 4 to switched ground negative. When the pin 4 swithed to ground the relay work as expected it joint/closed pin 1 and 2, however once the pin 4 ground is switched off the relay is still closed. Any explanation or solution to this issue ?
Clamps counter EMF from the relay coil when power is removed.
Standard LED function - Long lead is positive. It's easier than finding the notch on the case.
Good information.
I know using diode relay with seris. but i don't know what this using. Thank you for your grate job.
I was thinking if you can use a whistle as a switch and im searching for any ideas related to that
Excellent video. Well done.
Hello, great video 😄
I'm a beginner and I have a question :
Is it absolutely mandatory to put a protection diod in parallel with a relay?
Thank you in advance 😉.
Cordially.
Thank you very much because ,because you teaching us some thing very interesent,
Thanks, you saved my day
well done...
great job mahn....
I'm using 12v relay in my project....I used diode 1N4007,...With 230v ac power supply... When relay gets off my 16*2 LCD display shows unknown characters.. How to solve this problem... Plzzz
its verry helpfull to my project
thanks sir
i don’t understand . can i use a and 2v Led red light instead of a 0.7V diode? besides, why a 0.7v diode can withstand a reverse voltage which is more than 10 v.
Lekin switch ko stand mod pe kaisea rakhna??!ex.0n rahe ya off
Thank you very much..very good example....
How can I connect led lights in my car to come on when I unlock the car with my dome light and also be able to turn on with the fog lights as well?? ..... HELP!! 😩
Hi, how would you know what diode to use in a circuit?
Very useful video, thanks for sharing
please think and make and idea to use this near 10v return voltage for any project,
thanks good explain.
Thank you. Have you considering a remake of this video with a theoretical explanation of the field in inductor. It would make it one of the best videos on this topic!
simply, the magnetic field in the coil collapses when current is interrupted. That generates a current in the same direction as the original current. When you put a diode in reverse polarity across the coil of the relay it allows the current to flow from the output of the coil back to the input with very little voltage out of the coil(that voltage which forward biases the diode). When you put the string of LEDs as the conduction path from the output of the coil back to the input no current will flow until the collapsing field generates a high enough voltage to forward bias the diodes. So, the collapsing field will rapidly rise to the voltage needed to maintain the current which was flowing before the switch was interrupted, until all the coil's energy is dissipated. The most interesting thing about the coil(almost like there was some intelligence built into the coil) is that inductors are volt-second device, that is the output volts X time is equal to the input volts X time. So if you put 9 volts for 1 second into the coil you get 9 volt-seconds out of the coil. If you put a bunch of diodes in the feedback path(or flyback as it is usually called) voltage will have to rise higher to make the coil conduct. For example, if the output voltage has to rise to 27 volts to conduct, then the conduction time will be 1/3 of a second(27v X 1/3 second = 9 volt-seconds).
@@leeackerson2579 halo is this thing diode same as snubber diode
Now lets put a fuse in the mix lol, so it's ok to get any old relay from the junkyard, I've seen people do that, but which one?
Thank you!
Thanks
nice video, keep making video like this one
Thank you very much
Awesome explanation
+Sandeep naik
Thank you very much
¡Very useful, and very dydactic your video. Thankyou vm. Health for you!
great job
Diode is 1N4007?
I have see that is better to use 1N4148. (For little Relay)
Ok for DC but if AC Relay?
Really good video
Thanks for sharing.
Sir I making blinking ckt with 555 ic timer &one take chargeable china torch light open the torch & saprate connect the blinking ckt parallel to inside the toch light , the the lights blinking after one hour not blinking & not change battery. what will be mistake ,where the connect diode.
Crude but effective.
Larry
Interesting display. What is more amazing is that you manage to make a working solder joint with that cruddy iron tip.
2:38 why these red LEDs are not glowing when you on switch electrons can flow easily so explain me and why it is glowing in reverse voltage why not in forward voltage tell 🙏
Good explanation bro.
Is it required for AC currents?
Very good knowledge booster
Why is the negative connected to 2 pins.? It should only be one.?
as relay is both side open, so diode, to flow current in one direction
Not even close..
Where the diode connect to the battery positive parallel or series or connect to the circuit in parallel please explain sir.
Thanks for your information
Can I use smd diode? Thank you
I found why my IC worked terrible.... Thankyou..
Thanks and what that diod called ?
is it possible if i use this method in Solenoid??
You should do a follow-up video to show why diode protection aswell as diode protected relays and starter solenoids everywhere important in automobiles as this is why most vehicles on the road are failing with faulty switch panels broken climate control plus even burnt out sensors and engine computers plus transmission changes/overhauls. Even fuel injectors should be manufactured with built-in flyback protection..
Bhai relay kaha SE laya
The reverse supported voltage of a single LED is not much more than 5V, so, I would not have connected it to the 9V battery.
thanks for the very nice explanation sir😍
clearly understood thanks
So nice
Can I use 5v relay is not they so we can use 12v relay