Early we covered how to dim fixed colour LED strip smoothly from 0 – 100% using the LDP-CV-5A.
Today I’m going to explain how to dim a load of more than 5A using the same LDP-CV-5A.
First we need our LED strip and we’re going to use the UltraFlex warm white strip that we used in our dimming example which consumes 8.64W of power per metre. So the total power consumption of our 4m roll is 8.64 x 4m = 34.56W. The input voltage of the UltraFlex strip is 24V, so dividing 34.56W by 24V gives us the current of the 4m length which is 1.44A. We need to know this information because the PWM dimmer we are going to use is rated at 5A. So technically, we can dim up to 12m of Ultraflex with this dimmer. 1.44A per 4m roll x 3 rolls (12m) = 4.32A.
In this example we have 12 x 4m rolls of UltraFlex (48m) to dim and by using the equation above, our circuit has a current draw of 12.96A which is well above the 5A rated load of the LDP-CV-5A.
To get around this problem of load, we use our LDR-CV-5A-3CH. This dimming repeater has 3 output dimming channels at 5A each, which is a total load of 15A.
To wire the circuit, connect a 2 core low voltage cable from the positive and negative of the 24V power supply to the input +/- of the LDP. This input voltage powers up the dimming unit to provide the PWM signal. Now run a second 2 core low voltage cable from the power supply to the +/- power input of the LDR. Both of our control devices have 24V power to them. Run a 2 core low voltage cable from the +/- output of the LDP to the +/RED (R) of the LDR. The LED strips are low side switched, so the negative is RED, GREEN, BLUE. This provides our PWM dimming signal. Now connect a single loop from the RED terminal to the GREEN terminal, and from the GREEN terminal to the BLUE terminal. The LDR can operate on fixed colour or RGB and because we are only using fixed colour, we need to bridge the dimming signal across the other 2 input channels, otherwise we will only having dimming on the RED output channel.
Now connect a 2 core low voltage cable from the V+ and RED (-) output channel to 4m of UltraFlex (4.32A). Repeat this procedure with a 2 core low voltage cable from the V+ and GREEN (-) output channel to the next 4m of UltraFlex (4.32A) and a 2 core low voltage cable from the V+ and BLUE (-) output channel to the last 4m of UltraFlex (4.32A).
Turn on the 24V power supply and the LDP rated at 5A will provide smooth dimming from 0-100% of the 12m length (12.96A) of UltraFlex strip. The 24V input voltage to the LDP and LDR is not switched, the LDP switches the strip on and off and then by turning the rotating dimming mech clockwise the strip will illuminate up to 100% full intensity.
If you have LED strip lighting installed that you would like to dim, please contact us today and get your LDP and/or LDR shipped straight to your door.