October 28, 2011

Constant Current - Constant Voltage - Low Voltage Leds and Their Driving Circuits

As Led technology develops and new solutions appear on the shop nearly every week, it is getting more difficult to find out which explication is the best for your applications and most importantly, what features you have to pay attention to while purchase. In my old narrative at Ledcentre.uk.com about normal features of Led transformers I already mentioned that Leds need extra transformers features.

Leds are extremely sensitive to changes both in voltage and current, so if you are dealing with low voltage Led lights, wire-wound, stabilized transformers are the safe solution. As mentioned in the article, the majority of household Led lights operating at low voltage need constant voltage drivers for their operation. However, recently, with the growth of high power Led technology, constant current circuit solutions are becoming more frequent. Below, I will give a short narrative of how these circuits work, and why it is essential to pay attention to details at the buy of the driver for these applications.

Dc High Voltage Regulator

Three components matter in the operation of Led lights: voltage, current and heat. Leds are extremely sensitive to a change in all three of these, so their regulation is very leading for gaining a long lifespan. Current is often looked at as an exponential function of voltage, therefore even a small volume of change in voltage can corollary in a large change in the current. This is exactly why the majority of the Led lights need stabilized constant voltage power supply. However, current load can also growth with the growth of heat. To avoid overloading, Leds are driven from low voltage Dc via a current limiting resistor or constant current regulators. Someone else further explication is the cooling of the Leds with heat sinks. Not all Leds are attached to heat sinks though, which is why the limitation on the hours of application is so important. If Leds are operated longer than they are supposed to, they overheat, addition the current (even if within the range minuscule by the resistor), and lose some of their lifespan.

Constant current circuits are especially safe for high power Led lights, as they are convenient for 24/7 operation. If the Led light is man-made with constant current circuit, the current is fixed by the stabilized transformer, and it does not create further heat within the Led light. By less heat generation, the Led gains a longer lifespan. Also, constant current source keeps the Leds radiance constant. These constant current lights are, however, not convenient for operation with 12V batteries, since batteries are constant voltage power supplies.

There are obviously advantages of both circuits, and as usual we could stop that details matter. Never use a light requiring constant current with batteries or constant voltage power supplies. Always check this highlight of your light, and buy the essential transformer. And if you would like to know more about Led lights, check out the rest of my articles or caress us at Ledcentre.uk.com.

Constant Current - Constant Voltage - Low Voltage Leds and Their Driving Circuits

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