JLCPCB Prototype for $2(Any Color): https://jlcpcb.com
Using a 1N4005 diode to quench the high flyback voltage from a 12V fan motor. But the 33V transient suppression diode didn't work.
My other channel (Julian's Shorts):
https://www.youtube.com/channel/UCeewzdnwcY5Q6gcbnZKIY8g
Using a 1N4005 diode to quench the high flyback voltage from a 12V fan motor. But the 33V transient suppression diode didn't work.
My other channel (Julian's Shorts):
https://www.youtube.com/channel/UCeewzdnwcY5Q6gcbnZKIY8g
Hi There! Thanks for your video Would that be the same orientation if you install it on a 5 pin relay across the coil ? Many Many Thanks for your reply !
How does it work on a bidirectional
You need to make an informational video on how to properly diode protect your automobile so the average consumer can fight back as shoddy mechanics treating them as cash cows…The comments youll get will be overwhelming when you educate people in a manner that hits them with a hard reality and aids them with a simple solution that saves them mucho deniero..
Is this required for ac fans?
anyone know how to do flyback protection with a bidirectional dc motor
How can i make my rotary motor faster and powerful..pls help
For the 1N400x series of diodes, there's little sense in buying anything less than the 1N4007 (1000V!), unless you're a manufacturer trying to save pennies. On the other hand, in my years of salvaging stuff I've accumulated a bunch of different members of this series. This particular application is probably the only place I'd be using the lower-rated parts like the 1N4001.
The other issue with diodes is their speed. If they're not fast enough, the voltage builds up while they're waiting to conduct. Pulesjet suggested a capacitor and that will definitely help a lot.
Antiparallel Schottky gets my vote as worth a try
If you are using a relay, why are your low-side switching? If you leave the low-side intact, the motor's inductive current bleeds off to ground when you cut power. If you low-side switch then you do need a reverse biased diode because the inductor will discharge the magnetic field as fast as necessary to keep the current constant. If it hits an infinite resistance it will push current to raise the voltage till it arcs over. But the low voltage drop of the reverse biased diode gives it a benign path to cycle through the inductor until dissipated. This may be a bit more complicated with a motor as the rotor motion will induce a current in the stator while it winds down.
By putting the fan hovercraft style you are aerodynamically stalling the fan causing it to draw a lower current. Block the nozzle of a vacuum cleaner and you will hear it rev up as the fan stalls and starts to spin the air in the fan rather than blowing it.
Classic method to quench EMF
No point adding diodes in parallel. The forward voltages will all vary by some amount and the one with the lowest Vf will conduct first and so keep the voltage below the conduction point of the others, ie that one diode will still take all the load. 1A diode should be plenty, if you are still worried use a 1N54xx
We use 1N4004 (or 1N4007) diodes to suppress the back EMF from very large 24V 375mA electromagnets. If no diode is used, you get a VERY impressive blue spark when disconnecting…! [And if your finger happens to be in the way, it’s very painful 😖].
So in your application, you may only need one or maybe a couple of diodes. Try it and see how warm they get. See also my other comments…
I did a lot of testing with an oscolloscope with different diodes and configurations. Each have their advantages and disadvantages. For a coil backfeed i chose a high speed diode. And for a large inductor i used a combination in series. I forget what the results were for each test tho. Do some testing and show us the results! Edit: i think i put 2 diodes facing each other as the large inductor (was a spot welder leads) was causing the contacts to weld. It wasn’t just the negative spike but a positive spoke too!