The increased number of complaints from the readers regarding burning LEDs associated with my earlier posted transformerless 1 watt LED driver circuit, compelled me.

• What Is A Led Driver Circuit

I got a 10watt LED from Ebay but never thought that the driver and heat sinks are must-haves for this little master. When googled, I found several circuits of LED driver. But none of them are precisely a 'simple' circuit with takes 12v 0.5mA 1.5A DC input and lit the LED to full brightness.

So here are my questions folks:. I got few 220V to 12v transformers (with 500mA, 1A, 2A current ratings). Can you please give me a simple circuit diagram (preferably with a linear regulator or NE555 or any other easy-to-find IC/Transistor) to lit the 10 watt LED?.

Just saw a video, where the maker claims, even though the forward voltage rating of the LED is 9-12v, it will burn itself if connected to 12v and furnished a meaningful explanation. Whereas, we has shown that the LED glows ok with a simple 9v NiMH battery. I knew these LEDs need 2-3AMP current at 12 volts. What's the real fact of voltage and current for these LEDs?

Many thanks in advance. Sorry Sir, I am not a Pro. By profession I am a Java Architect working in one of the top IT firms in the world.

Electronics was my hobby in school days. I know, I have miles to travel to line up with the latest trends of Electronics. I often buy these 'Chinese' things from Ebay, cause they are cheap and serves my hobby purpose. And I thought just like Stackoverflow, StackExchange is a good place for novices too. If any resolved threads are there on this forum, could you please share the link? Thanks again. – Feb 9 '16 at 21:23.

Yet another simple LED driver request and yet another application for the LM317 as constant current source to be a simple (if somewhat inefficient) LED driver, but, being in current source mode, at least a good one for LEDs. – Schematic created using You can get brave and figure a value for the resistor, or you can sneak up on it with adding resistors in parallel as shown at an early stage, given you have sketchy parts. 1.25 volts is maintained between Adj and Out (the principle of the LM317's operation) - so each 10 ohm in parallel will add 125mA to the output in this configuration; or if you think the thing should take 900 ma, you could put together some combination that would get you close to 1.38 Ohms. Note that you'll burn over a watt in that resistor as well as the dissipation in the LM317 itself (which is best regarded as a 'smart resistor' at least for power use.) Other driver toplogies can be more efficient - this one is mostly simple, and involves just a few components. As commented above '2-3A at 12V' would be 24-36 watts. 10 watts at 12V would be 833 mA, 10 watts at 9V would be 1111 mA.

What Is A Led Driver Circuit

It is important to note that LEDs are primarily current driven devices - that is, the current, and especially the maximum current, is what you need to control. I got few 220V to 12v transformers (with 500mA, 1A, 2A current ratings). Can you please give me a simple circuit diagram (preferably with a linear regulator or NE555 or any other easy-to-find IC/Transistor) to lit the 10 watt LED? If you want to utilize the POWER LED to full potential then you should measure the thermal response of the LED in Current-Time domain. And it is related to your second question: just saw a video, where the maker claims, even though the forward voltage rating of the LED is 9-12v, it will burn itself if connected to 12v and furnished a meaningful explanation. Whereas, we has shown that the LED glows ok with a simple 9v NiMH battery.

I knew these LEDs need 2-3AMP current at 12 volts. What's the real fact of voltage and current for these LEDs? Production of LEDs(particularly POWER LEDs) has some scattering within the process so the their Typical forward voltages are spreading between a voltage level(9 - 12 V in your case). When dealing with 10W power LED, you should aim a test method based on constant current rather than constant voltage. You can have the LED tested with this simple configuration: – Schematic created using Start From drawing 100 mA and go up to 2-3 A. See the forward voltage for a wide current sink.

Then draw 0.5 A and check the temperature of the LED after a few hours. And then, you will have a countable data about your LED. If for 0.5A your LED does not produce Heat much, draw more current and repeat the test. Then you have a reliable data on your hand.

The universal high watt LED current limiter circuit described here may be incorporated with any crude DC supply source to get an excellent over current protection for the attached high watt LEDs. Why Current Limiting is vital for LEDs We realize that LEDs are seriously economical devices which can be capable of generate stunning illuminations at relatively reduced consumption, in spite of this these products are highly susceptible particularly to heat and current which are complementary guidelines and influence an LED efficiency.

However inside there was no installation CD and worst of all the Serial Number tag was missing. For a family with a number of kids. Serial Number tag missing. Netgear serial numbers.

Particularly with high watt LEds which are likely to produce substantial heat, the above limitations turn out to be essential problems. If an LED is driven with higher current it will usually get hot beyond persistence and get damaged, while on the other hand if the heat dissipation is not managed the LED will begin drawing more current until it gets ruined. Within this blogging site we certainly have analyzed a couple of adaptable function horse ICs for example LM317, LM338, LM196 etc which are usually linked with lots of excellent power regulating functions. LM317 is ideal for managing currents up to 1.5 amps, LM338 will permit an optimum of 5 amps while LM196 is designated for producing as much as 10 amps. The following we make use of these devices for present limiting application for LEds in the the majority of easiest feasible methods: The first circuit enumerated below is simpleness by itself, utilizing only one determined resistor the IC could be set up as a precise current controller or limiter.

The figure demonstrates a adjustable resistor for setting the current limit, on the other hand R1 may be restored with a set resistor by determining it making use of the following formula: R1 = Vref/current or R1 = 1.25/current. Existing might be various for distinct LEDs which enables you to be computed by isolating the optimum forward voltage with its wattage, as an example for a 1watt LED, the current could be 1/3.3 = 0.3amps or 300 ma, current for other LEDs could be computed in comparable fashion. The above figure would likely assist the highest of 1.5 amps, for larger current ranges, the IC might be basically restored with an LM338 or LM196 as per the LED specifications. Producing an existing regulated LED tubelight. The above circuit can be extremely effectively useful for producing accuracy current managed LED tube light circuits. General instance is drawn out below, which may be very easily altered according to the needs and LED features.

The series resistor linked with the three LEDs is measured by utilizing the following formula: R = (supply voltage - Total LED forward voltage) / LED current R = (12 - 3.3+3.3+3.3)/3amps R= (12 - 9.9)/3 R = 0.7 ohms R watts = V x A = (12-9.9) x 3 = 2.1 x 3 = 6.3 watts.