Can you please discuss the various methods of recovering the BEMF generated when a relay coil is de-energised. Recovery values of 80-90% of the input power in a pulsed relay driver circuit are possible, given the correct circuit/coil parameters. Cheers.
This is not something I have done, but I am sure there is someone out there who has done it. When I’ve used them I have not been in a situation where I needed to recover the back EMF.
I have Reed switches all around my house at this point (cabinet & closet lighting, intruder alerts on windows, etc), and I've tried just about everything I can think of (or Google), but I have yet to find a way to get the contacts inside the reed switches to stop fusing together after a couple of weeks to a couple of months! Even using as little as 5v 60mA, they always seem to go bad pretty quickly. Any ideas would be appreciated....
That is very annoying. I didn’t have trouble with that when I used one. I wonder if you are switching an inductive load. The sparks from the back emf can kill reed switches very quickly. Also if you are driving a capacitive load, the inrush current when the reed is switched over can fuse them. I suggest having a look at these aspects and also trying some higher rated reeds. I hope this helps.
Does the orientation of the reeds and or the the magnetic field come into play?
Not that I am aware of. They seem to demagnetise well after the field is removed , so it does not appear to be an issue.
Can you please discuss the various methods of recovering the BEMF generated when a relay coil is de-energised.
Recovery values of 80-90% of the input power in a pulsed relay driver circuit are possible, given the correct circuit/coil parameters.
Cheers.
This is not something I have done, but I am sure there is someone out there who has done it. When I’ve used them I have not been in a situation where I needed to recover the back EMF.
@@ElectronicsNotesI have working examples in my Lab if your interested in further discussion/schematics.
@@ricksampson6780 that would be interesting. Thanks.
I have Reed switches all around my house at this point (cabinet & closet lighting, intruder alerts on windows, etc), and I've tried just about everything I can think of (or Google), but I have yet to find a way to get the contacts inside the reed switches to stop fusing together after a couple of weeks to a couple of months! Even using as little as 5v 60mA, they always seem to go bad pretty quickly.
Any ideas would be appreciated....
That is very annoying. I didn’t have trouble with that when I used one.
I wonder if you are switching an inductive load. The sparks from the back emf can kill reed switches very quickly. Also if you are driving a capacitive load, the inrush current when the reed is switched over can fuse them.
I suggest having a look at these aspects and also trying some higher rated reeds.
I hope this helps.
thank you for the video, its very helpful
I’m really glad you found the video useful. Thanks for your comment.
☀️ 'promo sm'