Chauvet DMX-4 relay mode

Does anyone know if the Chauvet DMX-4 dimmer/relay pack has true relays in it when running in 'relay mode'? Or are they just running the dimmer at 100%? I checked the manual and it's just not clear.

Products DMX-4 Dimmer/Relay Pack | | CHAUVET® Lighting

I'm looking to take control of a large chandelier in an old church in which someone installed nice, beautiful (not) compact fluorescents...

Looks like just dimmer at 100%, this is not a true relay pack. Usually a true relay pack is only relays and no dimmers at all.
 
Actually I can't be 100% sure on use with CF's but it is possbile it would work. I'm not sure of the impact it would have on the CF starters, not sure how sensative they are. They do make CF's that can be dimmable but I doubt you have the right ones installed already. Maybee someone alse has tried this as I never have.
 
I have a handful of the Chauvet DMX-4 packs and I tend to think that they are actual relays. I've run flourescent blacklights, fans, all kinds of things off of them in relay mode with great success.
 
Does anyone know if the Chauvet DMX-4 dimmer/relay pack has true relays in it when running in 'relay mode'? Or are they just running the dimmer at 100%? I checked the manual and it's just not clear. ...
From a cursory glance at the circuit board, it would appear that there's no bypass of the triacs. The only way to know for sure would be to observe the output waveform on an oscilliscope. Whether or not the supply or load device(s) will be harmed when running in "Relay" mode is the subject of much heated debate, both here and elsewhere.
 
when fully 'on' the triac isnt going to distort the waveform (or the dimmer shouldnt, but who knows with the chinese junk), you will have a volt or two of insertion loss but that wont be much of a concern. The issue you may see, is the CFLs will randomly flicker when 'off'. This is because the triac leaks a small amount of current when off, this leakage current charges the caps in the CFL power supply circuit, and when the voltage becomes sufficient to ignite the lamp the CFL flashes. You can eliminate this by installing a ghost load. A 40w incandescent lamp should take care of it.

I am curious as to how you are wiring this pack in though. Is the chandelier already cord and plug connected?
 
I've had the thought of using non-dim CFLs in a set of string lights across a truss and dim them to make for a ghetto set of strobes. I haven't tried it though... and I'm not sure how long they would survive. Could make for an interesting look if they each strobe at different rates or out of sync from each other.


They do make CF's that can be dimmable but I doubt you have the right ones installed already.

The cost for dimmable CFLs is higher, and they are not as readily available as non-dim ones. So I would say there's 98% chance that they are not dimmable, but hey, someone might've actually been thinking smart at the time.

I have a handful of the Chauvet DMX-4 packs and I tend to think that they are actual relays. I've run flourescent blacklights, fans, all kinds of things off of them in relay mode with great success.

Most dimmers will not show too much issue running non-dim items at full, but the argument out there is that the chopping of the waveform that the dimmer performs will, over time, cause damage to item since it is designed for a non-chopped sine wave.
 
I have repaired a number of the Elation 600W per channel dimmer packs that are owned by a local rental company and my own company and here are my observations:

The printed circuit boards are manufactured out of FR4 glass fibre - a good quality board the tracks are cleanly etched with no evidence of undercut, the track widths are correctly sized for the current.

The Heatsink is adequate for the power dissipation. The components are from the manufacturers you would expect and the component part numbers are also the same part numbers that you will find in equipment manufactured in North America. The TRIACs are BTA16, 600V, 16A.

The reasons I have had to repair these packs:

A Customer droped a pack 10 feet onto concrete, and two TRIACs broke, replaced the TRIAC and the pack still works two years later.

A customer connected phantom power 48V from an audio snake into the DMX input on two packs and destroyed the RS485 receiver chip in each pack. Replaced the chip and worked fine.

One unit blew a TRIAC when a lamp failed - not uncommon on any dimmer pack at this end of the market, to avoid this requires some additional components in the TRIAC circuit, the price charged for this feature is completely unrelated to the price of the parts.

I have been impressed by the build stabndard of these units I have inspected the soldered joints at X10 magnification and the soldering is much better than I have seen on many commercial items.

This present a significant challenge for any domestic company as it is very difficult to compete at this price level. Low price does not always mean low quality and unfortunately the opposite is also true.

Just to note that all of the units I have repaired are rental units that have been out on weekly rental for a approximately three years and out of twenty units this has been the only problems.
 
I am curious as to how you are wiring this pack in though. Is the chandelier already cord and plug connected?

There are 4 circuits on the chandelier each with its own light switch. Inside the gang box I unwire the switch and attach a pigtail cord to the light circuit which then gets plugged into the dimmer pack. I haven't tried it for the CF's but I have done it for the wall sconces circuit that has standard incandescents. Not the prettiest solution but it gives me some control of at least some of the 'house lights' from my board up in the balcony. And it's temporary...

Thanks for all the repsones. I still haven't decided if I want to wire up the CF's or not but if I do I'll let you know the results.
 
I recently purchased four of these and was also curious about the switch mode. I have uprated my triacs from 16 to 24A and there do not appear to be any relays in the unit, also no sound of relay switching. Today I constructed a lead tapping off ~10V using a 1M ohm and 42k ohm resistors and connected this and ground to an oscilloscope. Hopefully will be posting a YouTube video soon if I can work out how! In dimming mode the waveform is horrible until 100% when it is virtually indistiguihable from the mains. In switch mode again when turned on the waveform is virtually indistinguishable from mains. However, at 0% in either switch or dimmer modes there is considerable ripple (about 2V peak cf. 15V peak from my resistor junction at 100%), which does concern me. Scaling this up (2/15)*240 = about 32V ripple when switched off. However this is with no load other than my two resistors which draw a few mA. When I connect a 1kW lamp to the channel in parallel with my resistors the ripple at 0% virtually disappears and when at 100% or intermediate the waveforms look much the same as without the 1kW load.

Photos (5V per large division):

Switch mode (on state), low load
DSC_0124.jpg


Switch mode (off state), low load
DSC_0123.jpg


Switch mode (off state), 1kW load
DSC_0149.jpg


Dimmer mode, (128 DMX value)
DSC_0130.jpg
 
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Scope is a little soft, but at 100% with some load you will still see a notch at the 0 volt point, which can raise trouble with inductive loads. At DMX 128 it is exactly what I would expect to see from any normal dimmer, although the 0 volt line should be flatter as long as there is some load. What you are seeing at 0 may be a little idle set (normal) and forward leakage through the circuit use to fire the triac. In other words, everything looks perfectly normal. "Relay mode" really is not intended to duplicate a real relay, but just the on/off jump that you would get using a real relay. Problem is it can cause problems in equipment that is designed to see line voltage or nothing. As you can see, ghost loading cleans this up quite a bit. With no load, it is possible to end up with a voltage build in electronic equipment that uses a power supply with a capacitor in it.
 
Thanks for your insight, I guess since the notches are minor should not cause problems with basic circuitry such as fluorescent blacklights, but would not advise powering complex electronics (say a CD player) using switch mode? Or of course you could use switch mode to trigger an external relay then use that to control your sensitive item (assuming the relay switches cleanly...)
 
Thanks for your insight, I guess since the notches are minor should not cause problems with basic circuitry such as fluorescent blacklights, but would not advise powering complex electronics (say a CD player) using switch mode? Or of course you could use switch mode to trigger an external relay then use that to control your sensitive item (assuming the relay switches cleanly...)
My experience in driving relays off of one of these packs is that you will need a ghost load. What tends to happen is the relay will remain open until you bring the channel up but will fail to open when you take the channel back down. There is enough leakage to just keep the relay magnet from releasing.
 

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