rJosh Posted September 22, 2009 Share Posted September 22, 2009 I have a Light-O-Rama LOR1602W with the MP3 Show Director and I'd like to connect a MAC series 46 air solenoid valve which operates at 120V drawing 5.4watts. I think inductive loads are to be avoided and a solenoid valve is an inductive load, though very small. Can I connect this, or will it break my LOR?Also, I'd also like to connect an Emerald Innovations 2-in-1 light show projector to the same whiz-bang LOR I mention above. Can I connect this too - it has a small motor? (I recall a post about the Mr. Christmas projector but can't find it again via the search)I'd connect the solenoid on channel 1 and the projector on channel 16 and yes it would be on/off only - no fades or effects. The sequence I'd use would keep each on for about 1 minute then off for about 1 minute.I'm 90% sure the answers are both 'yes'. It's that 10% that's getting me.Thank you,Josh Link to comment Share on other sites More sharing options...
Donald Puryear Posted September 22, 2009 Share Posted September 22, 2009 I all ways use a relay to control any loads other then lights. I use a RIB brand relay, these seem to work well with LOR. Link to comment Share on other sites More sharing options...
dennislgray Posted October 10, 2009 Share Posted October 10, 2009 But a relay is also an inductive load, just like a solenoid. They both contain coils. They both are used to generate a magnetic field to make a mechanical motion. I don't see the advantage of using a relay in this application. Link to comment Share on other sites More sharing options...
Cray Augsburg Posted October 11, 2009 Share Posted October 11, 2009 The relay electrically isolates the LOR controller from the "load".Cray Link to comment Share on other sites More sharing options...
Max-Paul Posted October 11, 2009 Share Posted October 11, 2009 As someone pointed out both a solenoid and a relay are an inductive load. So is a motor for that matter. I would use a solid state relay which does not have an inductive load. These SSR are made to handle a certain amount of Counter Electro Motive Force which is what kills most electronic switches. But, I would also put a MOV rated for 150V across the output of the SSR. A MOV is like a short for a very short time. Once the CEMF is greater than 150V, the MOV will short it out and protect the output of the SSR. At the same time, there will be no CEMF applied to the Triac on the controller board, which is a good thing. If you do not like the idea of a SSR, then as a minimum, put a MOV across the output of the controller.BTW your 5 watt solenoid is a rather small inductive load, but still use a MOV. It will make what ever is doing the switching on and off, last longer. Link to comment Share on other sites More sharing options...
dennislgray Posted October 11, 2009 Share Posted October 11, 2009 Cray Augsburg wrote: The relay electrically isolates the LOR controller from the "load".CrayYes Cray, I agree it isolates the load. But is simply replaces one inductive load with another. The thinking here my be that the relay is a smaller inductive load, but that may not be the case if the original load was a solenoid. Either way, I agree that a SSR with a MOV is certainly the way to go to avoid putting any inductive load on the LOR triac.Dennis Link to comment Share on other sites More sharing options...
rJosh Posted October 11, 2009 Author Share Posted October 11, 2009 Thank you for the replies! I guess my original question should have been "How much of an inductive load can it tolerate?". I already have a couple of electro-mechanical relays that are 125vAC load and control, but the ratings on my solenoid are in the same ball park as these relays. I wouldn't feel comfortable attaching the projector (because of the motor), but I do recall a post somewhere that these small inductive loads were tolerable. It seems though any inductive load will reduce the life of the LOR electronics, even though it may seem to work just fine at first.I'll look into the MOV - that will be a learning experience for me. Any suggestions on where and what to look for? An SSR does seem to be part of the ideal solution and I have ordered some from Digi-Key (Crydom CX240A5). I think one of the issues with a solution like an SSR is that it might not have enough resistance for the LOR board to be able to reliably control. If I have issues I'll just put a small incandescent bulb in parallel.Again thank you to all that replied! I'm still learning electronics and have enough knowledge to be really dangerous - sometimes I know a lot less than I think I do :?.Josh Link to comment Share on other sites More sharing options...
-klb- Posted October 11, 2009 Share Posted October 11, 2009 On the AC cards, the triacs switch off at zero current, so there is no current left in the coil to drive a voltage spike on switch off. I've not heard of any life span issues to the LOR hardware from driving small inductive loads, nor do I expect any.There are sometimes issues with the coils not drawing enough current by themselves to maintain the hold on current through enough of the cycle. So adding a C9 in parallel with the coils is usually a smart idea, and provides a drain for any inductive spike that happens when the current in the coil drops below the hold on current..So, add a C9 in parallel, and don't worry about it.. Just remember to never dim the channel, and check that the card does not have a maximum intensity configured. Link to comment Share on other sites More sharing options...
Cray Augsburg Posted October 11, 2009 Share Posted October 11, 2009 Duh . . .I knew that!(taking a bow and stepping back)I'll watch from here and maybe learn something. Cray Link to comment Share on other sites More sharing options...
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