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.
thank you for the video, its very helpful
I’m really glad you found the video useful. Thanks for your comment.
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.
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.
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.
☀️ 'promo sm'