5V working voltage Versus 12V working voltage

When it comes to LED strips, the sheer volume in the variety would be more confusing. Except the different kinds of IC chip pixels protocol, you always can see we offer 5V, 12V ,24V LED strips even we have customized 36V and 48V LED strips. There is always a need for careful consideration of power when designing your pixel lighting system. One of the important decisions that needs to be made is whether to use 5V led pixels or 12V led pixels. These are the two most common pixel voltage available. (24V pixels also be used, but we mainly discussed 12V today , 24V won’t be discussed in this article as the same principle applies, just to a higher degree than when using 12V.)

Struggling to decide if your led pixels lighting project should use 5V or 12V pixels? Read this post to find out more about the differences between these two voltages and which is right for your detailed project. 

Voltage Drop

This is one of the major factors when we are deciding what voltage led pixels to choose. Voltage drop occurs over any basic conductor length that carries current to a load. In this case, the LEDs are the load and the cable or flexible PCB strip is the conductor. Based on this principle, the voltage entering the first LED will always be higher than the voltage at the last LED. The more LEDs on the PCB, the higher that voltage drop will become. This will eventually reach a point after some PCB length, where the LEDs will no longer work correctly. If was the digital pixel led tapes, the voltage in IC chip was too low to work currently. 

12V pixels can overcome part of this limitation to a certain extent due to the additional overhead they provide when compared to 5V pixels. As a result, typically when using 12V led pixels you will always be able to go further in terms of the leader cable length and the total length of the fixture itself compared to using 5V pixels before needing to inject more power.

Considering a real world use case of 5V pixels with 20AWG wire which is the most regular cables soldered on our led strips, the most LEDs you can typically power before voltage drop becomes a problem is about 70. However when using 12V pixels, you can expect to this to be around 140 LEDs. This helps to demonstrate the real world effect of the voltage drop.

Efficiency

When considering 5V or 12V pixels, the other major factor is the amount of overall power required. The main shortcoming of the 5V system is that voltage drop is a more significant limiting factor. However 5V systems are much more power efficient than 12V systems; a 5V linear system will always be 2.4 times more efficient than it’s equivalent 12V system. To understand why this is the case, we need to know a little bit about how power works. DC power is calculated using the formula P (Power) =V (Voltage) x I (Current). So we can immediately see that there is a relationship between the power, voltage and current in any DC system.

Example

Let’s assume we have one meter of 60 RGB pixels and want to calculate the power usage using both 5V and 12V. Doing some simple math we have:

Total Current = 60 x 0.06 (assuming 60mA per LED on full white) = 3.6 Amps

Total Power (5V) = 5V x 3.6A = 18 Watts

Total Power (12V) = 12V x 3.6A = 43.2 Watts

So immediately we see that to achieve the same end result, using 12V pixels will require 43.2W and using 5V pixels will only require 18W. Then we simply divide the two to work out how much more efficient the 5V system is compared to the 12V system: 43.2W/18W = 2.4

So the 5V system is 2.4 times more efficient than the 12V system, meaning you need to provide 2.4 times as much power as a 5V system to achieve the same outcome.  You may be wondering where is all this extra power used up in the 12V system? Well, it is dissipated in the form of heat!

As we known, the 12V strips normally are 3 individual LEDs in series for one segment or one pixel, as this increases the total consumed voltage by a factor of 3 to about ~10V, forcing more of that extra power to be used up instead of being wasted as heat.

A Solution

It is possible to get around these aforementioned problems to some degree. One solution is to use a DC-DC converter system which is highly efficient (~90%) and converts the higher 12V input voltage down to 5V for use by the LEDs. Or converts the 5V voltage to 12V. But this solution has a disvantage that would have higher cost on this DC-DC converter.

Conclusion

There are advantages and shortcomings to choosing different voltage pixels. As usual, it will depend on your specific installation as to which is the best option.

• If you need to conserve as much power as possible, then 5V led strips will be your best choice.
• If you need to have a longer length cable between the pixels and power supply and a longer continuous run of LEDs, then 12V led strips are better suited.
• If you require individual LED control in one pixel strip, then the 5V addressable led pixel tapes may be you are interested in, but 12V indidvidually addressable led stirp maybe preferable too. 
• if you don’t need the individual LED resolution, then a 12V pixel strip using 3 LEDs per pixel may be more than enough.
• Notwithstanding these guidelines, there are some solutions which try and leverage the best of both worlds, such as you can choose DC-DC converter system.