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DM253
30-08-2005, 12:13 PM
Hello,

We have a rather large quantity of LED tubes from a far eastern supplier.

These tubes each have 144 (44 x 3) LEDs and accept 230V input on 4 channels (3 for R.G.B and 1 for Neutral) to carry out colour changing. The tubes have no 'intelligence' built in.

Is it possible to use these in some way with Pixel MAD?

What would be the control interface between Pixel MAD and the tubes themselves?

samsc
30-08-2005, 12:48 PM
no dmx?

is the input dimmable in any way?

is it an a.c. 220v input?

DM253
30-08-2005, 01:12 PM
Richard,

There is no DMX control.

The controller that came with the tubes is a bare bones - a real disgrace.

I do know that the tubes are 220V DC though and since the controller is only sending DC volatge to the tubes, they are presumably also dimmable.

DM253

samsc
30-08-2005, 01:29 PM
you need to find out.

something doesnt quite add up.

LED's dont need high voltage power sources.

so their PSU might not be dimmable.

DM253
31-08-2005, 10:45 AM
Richard

Haven't dissected one of these as yet, but I can confirm that each tube can accept 220 V DC on 3 discreet chanels to light up in red, green & blue respectively.

44 x 5V LEDs totalling upto 220V DC doesn't make sense does it ?

Possibly there is some sort of a resistance or a step down transformer for each channel within.

Thoughts ?

DM253

samsc
31-08-2005, 02:47 PM
suggest you contact the manufacturer - again.

220v dc isnt very standard?

doesnt make any sense.

DM253
04-09-2005, 04:30 PM
Richard,

You suggested checking again with the manufacturer.

I went one better.

I set up the tube myself with direct 220V DV (no controller) and checked it out.

The tube has 4 wires coming out from each ends, terminating in a 4 pole connector (one male, one female). These are the uinput and output cables.

One of the 4 wires is a common and the other are for R,G,B respectively.

Aplying 220V DC across the black (common) and the Red, Blue or Green wires will cause the Red, Blue and Green LEDs to glow respectively.

Only interesting thing is that typically one would expect the common to be the -ve in the scheme, but in this instance the polraity seems to be reversed and so applying 220VDC +ve on the black and -ve on any of the R,G,B cables will cause the tube to emit R,G,B colours.

I have built a prototype DMX - DC dimmer and I am able to do global colour change on the tubes.

DM253