Snubbers inside LOR box? Is it safe/logical?

[ace_master]

Hey, I just got a bunch of 47k (metal oxide, 1w, 5%) resistors, and was wondering how necessary it was for the snubber to be located out near the LED strings inside a male plug?

Would it do the exact same thing if I were to wire the resistors right to the LOR controller for each of the 16 channels?

Would this interrupt the lights from acting normal?
Would this burn up the resistors quickly?
Would it cause the box to get too hot after a 3 hour show?


Thanks, Rob

[Victory402]

Rob,

I have a dc card that controls some 12v relays. I put the diodes right on the controller terminal block with no ill effects. I have not heard of anyone doing it this way, but really don't see a problem with it. I would wait for some more response on this before ya pull the trigger though.

[Terry Chauvin]

It sounds fine to me. I guess the only thing that comes to mind is heat. 16 1W resistors in the box could generate some heat? I do not have the LEDs yet and have not made any load devices to see if they get warm. My guess is that .4 watts times 16 is not much heat.

[Bruce Wallick]

I never understood the location thing, because the snubber is in parallel with the lights and would have the same effect no matter where it was located IMO. In terms of a transient response, there would be some delay, but we're talking millionths or billionths of a second,

The one thing keeping me from snubbing inside the box was the location of a nearby ground connection. Where were you planning to connect the other end of the resistor to?

[Jim Saul]

Terry Chauvin wrote:

It sounds fine to me. I guess the only thing that comes to mind is heat. 16 1W resistors in the box could generate some heat? I do not have the LEDs yet and have not made any load devices to see if they get warm. My guess is that .4 watts times 16 is not much heat.

I'm with Terry that the heat would be the biggest concern, but if you are using the controler outside in Ontario, Im going to guess that heat is NOT a problem

[Ponddude]

There are actually rumors that the newer versions of the LOR cards will have the resistors inline. They have to go after the triac so it creates a load on triac.

[Ponddude]

I also won't go with a 1watt resistor. 1/2 watt would be better.

[Terry Chauvin]

There is no need to go buy 1/2 watt resistors if you already have the 1 watt. The power calculation is power = voltage squared / resistance. 1/2 watt would also be fine.

[ace_master]

Thanks for all the input guys...

I would have considered the 1/2 watt resistors if I didn't want to be safer than sorry, because I have no idea just how many strings I will put on a channel in the long run.

I was thinking that if I were to put it right on the board, I might solder them right to the back of the board, and then set the board back in the enclosure having them out of sight and out of the way completely... I have 300V rated wire I can use to extend the length to the positives. And I will be using heat shrink to cover as much of the resistor/connections as possible. Followed by electrical tape if necessary.

I'll have to check the clearance behind the board though to see just what my options are.

And being in Ontario, I don't see the heat being a huge issue, but it's something to conciser for Halloween shows, i guess.

[ace_master]

Well, I just finished soldering the resistors to a board on the positives and having them connect and run through a single ground wire (for each 8 channels) to the unused pin on the neutrals. Wrapped in red to remind me that they are hot wires when unit is working.

I know I did a spotty taping job, but it's 3:30AM here and I have to work tomorrow, lol.



If anyone has any input on this, please let me know. At first it seemed weird to have all the positives connected through resistors to the same ground... but looking at the whole picture... that's the way the whole thing would work if the resistors were out near the strings.

I'm just a little put off that there are essentially only 2 resistors between each positive pin (would this not turn channel 2 on a little when i turn channel 1 on?). It seems to make sense when I look at it as if they were out on longer cords like everyone else does, but I'm so confused when I think about it, lol..

Its time for bed... hopefully someone can chime in and tell me 'you've done it all wrong', or 'that looks perfect' by the time I get back to the boards tomorrow.

I don't intending on powering this controller until I hear some feedback, but It is supposed to be part of my show, which starts at 6PM every tonight. I hope I get the go ahead to get it out there by show time.

[Max-Paul]

Well its after 6PM central time. And I am not real sure what time zone your in. It appears that you have things wired correctly. I am not sure what this biz is about with the resistor between two channels is all about.

Ok, forget the wattage hogs. And the worry warts about heat. If anyone would just sit down and do the math they would realize that 120 / 47K = 2.55mA. And as someone pointed out Watts is calculated 120 * .00255 = .31 watts. Times 16 is less than 5 watts of heat. Which is like putting a C7 ican bulb in your box. I can see this helping keep the moisture under control, a good thing.

[Max-Paul]

Ponddude wrote:

There are actually rumors that the newer versions of the LOR cards will have the resistors inline. They have to go after the triac so it creates a load on triac.

Ya, Dan and company are going to have to adapt to the change over to LEDs just like we are all having to change our fades to what LEDs range is.

[ace_master]

Had a talk with my dad this morning (he's an electrician). He said it appeared good to go... so I hooked it all up and tested it out. worked fine... so I enabled the scheduler for 6-9. and took off for work. It's now 9PM here (Eastern time btw), and I just went out during the last song and checked the heat on the resistors in the box... they were actually quite cold to the touch. The temp where the box is is about -5*c.

This seems to have worked great. I just wish I decided to do it before December so i wouldnt have to disconnect the whole box to bring it inside to work on.

[Max-Paul]

Ace,
Only a few lucky dogs have had all go well in the first year. I think the most of us have little things that pop up for the first several years. We work through the little problems and by the 3rd or 4th year things are starting to look and act professionally. One example is that I have brand new strings of LED. And at the end of first year I had a string fail. start of 2nd year I have had a failed string. I hope that by the end of second year all failures have been identified and no more for a few years. At the start of the 2nd year I found that I should have deleted one version of a song and only kept the correct version. Because I did not delete the one version. I had the wrong one in my show. Didnt look well. Now have deleted wrong version.

[ace_master]

I just outfitted a second controller with resistors. It took just under 2 hours... which works out to about 7 minutes per channel from start to finish (could be done in less, but i was in no rush).

I have a few plug-in snubbers on hand, should i ever need to add a little more resistance at the other end of a line as well.


Thanks Max. I've just run into a string of lights myself, that are only half working. Luckily they are icicles on the edge of the display and don't cause too much of a visual issue, I'm going to have to get in touch with CDI about it, I just got them last month.
I kinda like the little issues that pop up, personally... good opportunity to learn about new things... just as long as I'm not on a deadline, or have a long to-to list on the go.

Second controller ready to go: