ATX LED recommended LEDs / DR2 or DR1 channel

Max # of Fixtures

Look at this chart of Lumen output from a LED compared to current.

You will note that the Lumens out are a function of the current.      Nowhere in this chart, or any manufacturer's chart, is a curve of Lumen output by Voltage. Furthermore, you will note that that lumen output can go to 0% smoothly as the current nears 0mA.   There is no flicker in DC by the LED.  Further, the LED outputs more Lumens per mA at lower currents than higher currents, so there are many factors that we have designed into the system.

Conversely, look at this chart of Voltage as a function of current and temperature  The leds we use have a similar curve, from 3.1 to 2.9 volts.

The Voltage varies changes by temperature mostly, but also by small manufacturing process variations. In an installed system, the loss in wiring and connectors accounts for further voltage variation.

In an ATX LED system, we focus on current, and do not have to worry about Voltage until the forward voltage is greater than the available voltage in the system.

In our 48 to 51 volt systems, we have 43 to 46 volts available for the LEDs. - that means up to 14 individual LEDs chips in series in a 48v system,  15 in a 51v system.

Our Fixtures have from 1 to 3 LED chips in series in each fixture.

We do not operate our LEDs at full power, that would be a forward voltage at the worst case (cold start, highest current) of about 3.1 volts per chip, or 9.3 volts per fixture, or 37.2 volts for 4 fixtures, or 46.5 volts for 5 fixtures. 

We do operate at about 60% of max power, resulting in a Vf of about 2.9 volts per chip, or 8.7 volts per fixture, or 34.8 volts for 4 fixtures, or 43.5 volts for 5 fixtures.  The DR2 and DR1 can supply 85% of the input voltage - 43.5v from 51v.

Another way to say this, is that with conventional wiring, you can load up a circuit until you run out of amps and trip the breaker.   In driverless, high efficiency, low power, series wired long life LEDs - you run out of volts when you load a circuit with too many fixtures (staying within the NEC 60 Volt section 725 / article 411 limit).     ATX LED has designed its systems with a 51 volt limit.

Traditionally, strip light systems have voltage drop problems because they attempt to run 50 or 100 watts at 12 volts, the voltage drop is high percentage because of the loss in the copper at 12v is 16x higher than at 48v.   Loss in Watts is equal to I²R, where I is current and R is the wire loss.  By way of example, to deliver 30 watts at 12V requires 4 times the current compared to 48 volts, which, when squared is 16 times the loss.  

The ATX solution defines an entire system from the wire size to the distances to deliver the light.  This allows our system to fully compensate for the "voltage drop" that is an immutable physical property of wire, connectors, temperature and aging.   We focus on delivering the current required, while staying under NEC limits, for the lowest installed cost, highest efficiency, longest lasting lighting system with perfect dimming.