24VAC to DC, how to filter?

[Mishael]

I work at a roller rink and we have been purchasing LED DMX tubes that are each 1.5 meters in length to hang around our rink. The current lighting system that is installed all operates off of 24VAC and our tubes are all DC. We have upwards of 10KVA available power where we need it, but it needs to be converted to DC. When it is all said and done, we will have 256 tubes at 18 watts each, for a total of just over 7100 watts. The tubes will be broken into 37 groups of 7 tubes each (the reasoning for this has to do with their DMX control, not power) for individual sets of 126 watts. There are several groups of large 24VAC transformers throughout the rink, multiple converters would be off of one AC transformer

I am curious in how to proceed with the conversion of AC to DC. I am aware I need to use a bridge rectifier and I would like these to be filtered with (a) capacitor(s) but I am unaware of the capacitor rating required, and I don't know the best way to distribute power amongst the groups.

Summary:
Should I have fewer large power converters, or more small power converters? How many groups should I power per converter?
What should my capacity headroom per converter be? (the lights are only 18 watts when all 96 5050 LEDs are at full white, which is rare but it will happen)
How can I fuse these? (manual reset, not one-time or auto reset)
What should my caps and bridge rectifiers be rated at, and what would be the most reliable and filtered the best?
What design of circuit is optimal?

 

[KeepItSimpleStupid]

What do you know about your DMX system? What voltage/current/power does it require? A LED DMX tube tells me nothing. OK power in Watts, but that isn't enough.

24 VAC tells me next to nothing because power or current is missing.

You might be putting the cart before the horse. Where there is 24 VAC, there may be a higher voltage and it might make sense to utilize that.

There are supples that will convert 24 VAC to various DC values. 24 VAC will not directly convert to 24 VDC. It would be about 33V or 1/2 that depending on the method. Available current also changes depending on the method.

So:,
Link to DMX system?
Link to tube?
Secondary specs of 24 VAC system currently in place?
Primary of 24 VAC transformers?
About how may exist?

What have you bought? (That maybe you shouldn't have?)

The transformers are likely in some sort of enclosure. Tell us more about that.

 

[crutschow]

You may be able to operate the LEDs directly from the rectified AC without a filter. The LEDs will flicker but the flicker frequency is 120Hz from a full-wave bridge rectifier and that frequency is not noticeable by most people.

 

[KeepItSimpleStupid]

DMX is a light control protocal. So, the controller may not like pulsating DC.

 

[4pyros]

I would bet the new DMX lights are 12 volts DC.

 

[KeepItSimpleStupid]

Well, it looks like this https://www.ecolocityled.com/product/dmx_decoder_24ch/dmx_lighting_control controller needs 5 to 24V, so I think it's up in the air.

 

[4pyros]

Well, it looks like this https://www.ecolocityled.com/product/dmx_decoder_24ch/dmx_lighting_control controller needs 5 to 24V, so I think it's up in the air.

Do you mean "If it looks like this"

 

[KeepItSimpleStupid]

No. It's just an example that takes 5-24V. Which means 12 isn't the only option. I have migraine today. I might screw up responses.

 

[4pyros]

No. It's just an example that takes 5-24V. Which means 12 isn't the only option. I have migraine today. I might screw up responses.

Hope you feel better

 

[Mishael]

What do you know about your DMX system? What voltage/current/power does it require? A LED DMX tube tells me nothing. OK power in Watts, but that isn't enough.

24 VAC tells me next to nothing because power or current is missing.

Each tube requires 18 watts at 24 VDC

You might be putting the cart before the horse. Where there is 24 VAC, there may be a higher voltage and it might make sense to utilize that.

There are supples that will convert 24 VAC to various DC values. 24 VAC will not directly convert to 24 VDC. It would be about 33V or 1/2 that depending on the method. Available current also changes depending on the method.

I would have to poke around in my ceiling to find the various xformers. To my knowledge, I have a very large quantity of 500VA (upwards of 12) and several 2KVA. I know the 500VAs are running at 120, I don't know about the 2KVAs, I know one is running double pole 277VAC.

So:,
Link to DMX system?
Link to tube?
Secondary specs of 24 VAC system currently in place?
Primary of 24 VAC transformers?
About how may exist?

What have you bought? (That maybe you shouldn't have?)

Link to the DMX system a 3 pin XLR connector in a power tee which has a power connector, a 4 pin tube connector, and a DMX connector. the DMX and power systems are isolated from each other.
Link to tube is above
Secondary specs: great question, all any of the xformers say is "12-24" but they look about the size of 500VA whereas my 2KVAs are actually labeled as such
Primary on my small ones is 120 whereas the large ones I am not sure about but I know one is 2-pole 277
I estimate there are at least 15 transformers.
The only thing I have is the LED tubes. If this whole idea doesn't work out we are prepared to purchase 24 VDC power supplies that operate off of 120 VAC.

The transformers are likely in some sort of enclosure. Tell us more about that.

The 2KVAs are their own partial enclosure with wire connections made inside of an access panel on the base. The 500VAs that I know about are in a long, narrow enclosure. There are 8 of them in a vertical row in an enclosure about 8-10" wide and at least 3 feet long and at least 8" deep

 

[KeepItSimpleStupid]

Instead of trying to repair the ding, you might want to concentrate on finding the appropriate product which does not mean the cheapest from China.

I did find this:

**broken link removed**

and with a little digging, this: **broken link removed**

Class 2 is important and the 90 W limit is important, because that is the limit of a class II power supply. Note they are available in 40 W too. I suppose they want you to hook up red, blue and green tubes to each supply with a 20' maximum between the supply and the tube. Class II wiring doesn't have to be in conduit.

They are inherently "power limited" and low voltage. e.g HVAC thermostat wiring, doorbells, intercoms, and fire alarm systems (FAP =Fire Alarm Panels).

For a safety system I put together, I did use an FAP supply, which is typically UL approved. They typically are battery backed up and are 24 V. 12 and 24 are available. Another use is CCTV cameras.

This http://www.altronix.com/products/pr...x.com/products/product.php?name=AL1024ULACMCB is typical, but not necessarily what you would need for a 24 DC distribution.

The idea is to provide fused or PTC (positive temperature coefficient thermister) protected power limited outputs. Usually battery backed up (unnecessary) and usually controlled in some fashion for "door strikes" etc. The FAP might, for instance force certain doors open. In some respects, you could use one for "emergency lighting" if you only need a 24 VDC supply.

I actually used one from this company: http://www.alarmsaf.com/

It's also 120 to 277 V input. yep 277 is a lighting voltage.

I would suppose that you would order "spares"

So, with 15 transformers, you will have 15 DMX controlled lamps and arranged 3 x 5; 5 groups of red, green and blue.

Does, the current DMX controller operate on the primary (120/277) or secondary side (24 VAC)? You effectively want to use the variable AC to get "variable DC"?

EDIT: A little more info about class II and FAP supplies.

 

[4pyros]

Link to tube is above

Where???

 

[jomaliens]

I think you should need a controller(**broken link removed**) with 12 to 24V, so I think it's up in the air.