# Drivers and How They Work

(transcript from the video)

## Drivers & How They Work

I would like to show you our drivers that we use for our LED’s and how they work. On the test bench here I have seven fixtures simulated. I have the little circuit boards that go on the fixtures where we can jumper the input wires in and then jumper between fixtures. I also have seven of the LED arrays that we use in our fixtures hooked up. Rather than all the fixtures here I thought I would go ahead and make it a little more compact.

As you can see in the volt meter, we have 48 volts applied to the circuit and right now we are drawing 0 amperes. If I put a shorting plug in and complete the circuit to the first fixture you will notice we are now drawing 1 amp and have 6.17 volts applied across the light. The minute the light turns on, the voltage that was 48 volts drops to the forward voltage of the LED or 6.15 volts.

Now I can turn that LED off by removing the shorting plug and we will go to the second fixture. We will put the shorting plug in on that one, and we can see we now have a voltage of 12.04 volts and we are drawing 1.2 amps, basically the same thing.

Now let’s go to the third fixture, I’ll unplug the jumper, put the shorting plug in completing that circuit. We now have a voltage of 17.84 volts and an amperage of 1.02 amps.

I think you can see how it’s progressing pretty good here, but let’s go ahead and go to the fourth fixture. We’re not showing a voltage drop across four of the LED arrays of 23.64 volts but we’re still flowing 1 amp through the circuit.

Now we’re going to our fifth light. The voltage drop now is 29.4 volts that’s one, two, three, four, five fixtures are lit up. Still 1 amp.

Now let’s go to the sixth fixture. The voltage across it now is 35.1 volts and we’re still drawing 1 amp.

We’ll hooked up the seventh fixture and see how that goes. Now with seven fixtures in line we have a voltage drop of 40.8 volts and 1.02 amps is flowing through the circuit.

So this shows you how, with different supply voltages 12, 24, 36 and 48 volts, you can run different amount of lights on each of the output channels. Thanks for watching.

PMMI Lighting, LLC