Page 1 of 1
Flyback / snubber diodes
Posted: Wed Feb 22, 2017 4:45 pm
by Jrhaas60
I'm using 24vdc solenoids for my glycol valves. I'm thinking I need flyback diodes to protect the relays. Any experienced opinions out there? Thanks
Re: Flyback / snubber diodes
Posted: Fri Feb 24, 2017 4:25 am
by Jrhaas60
I thought I would get some response to this. Anyone running 24v dc solenoids who've had relays fail and not know why? I've ordered my diodes and will be adding them either way. Too cheap and easy not to do it and I do believe it will help relay life in my case. Not sure if it's significant at 12v. Cheers.
Re: Flyback / snubber diodes
Posted: Fri Feb 24, 2017 8:47 am
by JonW
Most relay boards come with flyback diodes these days. Are you using individual relays that don't already have the protection?
Re: Flyback / snubber diodes
Posted: Sat Feb 25, 2017 6:34 am
by Jrhaas60
I'm using a board from electronic salon like I saw used by many others on this forum. There are no diodes across the output contacts shown in the schematic linked to below for these boards.
https://images-na.ssl-images-amazon.com ... HTDz-L.pdf
Re: Flyback / snubber diodes
Posted: Sat Feb 25, 2017 6:58 am
by JonW
A flyback diode is across the coil contacts, not the output contacts. The board you've shown does have a flyback diode on the coil.
Re: Flyback / snubber diodes
Posted: Sat Feb 25, 2017 7:34 am
by Jrhaas60
You need it on both sides for the same reason.
Re: Flyback / snubber diodes
Posted: Sat Feb 25, 2017 7:39 am
by Jrhaas60
You need it on both sides for the same reason.
Re: Flyback / snubber diodes
Posted: Sat Feb 25, 2017 7:41 am
by Jrhaas60
Oops on the double posting.... newbie mistake...