![]() ![]() A brightness of 100 uses about 19mA from the graph, times 2/3 since we know we’ll only be using two of the three colors at a time, give us 12.5mA per pixel.ĭepending on how harsh of constraints you impose on yourself, the amount of power you need for each pixel can be greatly reduced. For example, if we know we only want to use yellow (red + green) and purple (red + blue), at max brightness of 100, the worst case would be 12.5mA per pixel. If we only program our LEDs to be exactly red, green, or blue, we can cut the power consumption down to one third since two of the three LEDs are off. If we use a combination of two of the three LEDs on each pixel we can reduce the power to two thirds the normal consumption. Similar to reducing brightness, we can also reduce power but turning off all of either the red, green, or blue LEDs in the strip. Many strips even have an extra pair for 5V and GND wires at each end specifically for “injecting” more power. To fix this we just need to apply the power and ground to both sides of the strip. By the time we get to the end of a long strip the voltage has sagged and the brightness and color quality of the LEDs has deteriorated. If we try and set all of the LEDs to max white brightness, it draws too much water (current) for these little pipes to carry. These act like pipes carrying the water (current) through the strip. If the LEDs are taking a shower in this analogy, low water pressure is no good.Įvery strip has little wires embedded into them to connect one LED to the next. If we try and turn up the water flow (current) higher then the supply can handle, the water pressure (voltage) will go down. Trying to pull large amounts of current can cause the voltage to sag, reducing the brightness of your LEDs, or worse damaging them or your power supply.įor those less familiar with the electrical terminology, the voltage can be thought of as water pressure and current as water flow. Even on a quality supply I’d recommend giving around 20-30% of headroom to be safe. Many power bricks, especially those that advertise over 5 amps, use cheaper components and cannot actually maintain that level of current. This means if we are willing to sacrifice some brightness, we can safely connect more LEDs per amp of current.Īs a word of warning, it is important to use a quality 5 volt power supply. Additionally, when thinking about the power requirement we only have to consider the worst case scenario. If we’re a little clever about how we program our LEDs, we can get away with connecting many more LEDs with a less powerful supply.Īs you’ll see, these LEDs are BRIGHT! Setting them to max 255 brightness can make them downright hard to look at without any diffusion. However while this is a safe approximation, we would only use the full 9A when we have all the LEDs set white at max brightness. This is why we picked a 10 amp power supply for the primary guide where we use a 150 pixel strip. Therefore for an entire 150 pixel LED strip we would be using a maximum of 9A of power. This give us 20mA + 20mA + 20mA = 60mA per pixel. *2 The NPN open collector rated output is: 50 mA max./ch (20 mA when adding an expansion unit) less than 30 V, residual voltage less than 1 V (less than 1.5 V when adding over 6 units including the main unit) The PNP open collector rated output is: 50 mA max./ch (20 mA/ch when adding expansion units), less than power voltage, and less than 2 V residual voltage (less than 2.5 V when adding over 6 units including the main unit) *3 If there are over 6 additional expansion units, please use a power voltage of 20 to 30 V.The defacto advice on the internet is to make the assumption that each of the RGB lights will use at maximum 20mA (the actual value is slightly lower). ![]() *1 Assign an input of your choice to the 4 external input lines before using. 10 to +50 ☌ (No condensation or freezing)ġ0 to 55 Hz, Double amplitude 1.5 mm, 2 hours in each of the X, Y, and Z directionsĬase / Front sheet: Polycarbonate Key tops: Polyacetel Cable: PVC Open collector output (NPN, PNP changeover possible/N.C.) *2 Open collector output (NPN, PNP changeover possible/N.O., N.C. Industrial Continuous Inkjet Printers / CIJ Printers.Laser Marking Systems / Continuous Inkjet Printers.Electrostatic Meter / Static Fieldmeter.Profile Projectors (Optical Comparators).Inductive Displacement/ Gauging Sensors.Optical Micrometer / Digital Micrometer. ![]()
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