rupper

Hi Nifty, Thanks for answering. Happy to have someone who had the same problem once to talk to! As far as I know (which is not much) the Snubber will take a lot of the feedback current generated by an inductive load, but it needs a few milliseconds to warm up to take the energy. In that very first milliseconds you need something else which works quick and absorbs the initial voltage peak, so that what the Varistor is used for. I understand you tried the snubber + varistor, or just the snubber alone? In case of the second, do you think it may be worth it to try the snubber + varistor? (i.e. is this dangerous, like it could burn the dual relay bricklet or master brick, or will it just create software problems on the brick until reset?) Cheers, Roger.

Hi all, I've recently bought a set of 3 dual relay bricklets to use with diverse devices like, amongst others, two electrovalves. Since these work with solenoids at 12V DC I guess I'll have trouble with current feedback as reported. This is my first electronic project (I'm computer engineer, used to take care of software part) so I'm trying to learn fast. After reading a lot I've arribed to 2 conclusions: 1) For a 12V DC valve, I'll have to put a 12 VR diode in parallel to the valve, facing forward to positive polarity. 2) For a 240 VAC, 2A fluorescent I'll have to put a 380V Varistor in parallel to the fluorescent. A snubber circuit would also be good for this one, since the varistor will burn a lot of energy at the beggining but won't last for long. But currently I don't know how to calculate the snubber circuit so I'm waiting to confirm I need it before doing it. I just wanted to share this with you english speakers on this forum, since this topic was forgotten 6 months ago (discussion followed in the german forum, unfortunately I can't understand a word, not even with translators) and more people might found theirselves in this very stressing situation of discovering this 2 relays you bought won't be able to switch an inductive load. Also, for the record, if nothing of this works, Solid State Relays might be an alternative I guess (probably random turn-on SSR), could we get a SSR bricklet in the long term?