1 Watt Led Driver Circuit

Using strings of 4 gets you almost 12v with a 2 9v led.

1 watt led driver circuit.

So current need is 1 3 2 312ma that normal current is 350ma. Here a simple 1 watt led driver circuit based on a modified joule thief design runs on a 1 5v single aa or aaa cell. 1 watt to 5 watt led driver solution for high brightness leds. This circuit is pretty efficient and it can power a 1 watt white led quite brightly.

Once you have understood the circuit you can calculate the current rating required for your led and build it on a breadboard to test it. C1 together with the inductor l0 and c2 make up a pie filter network for cacelling emi disturbenaces. My circuit looks like as shown below after i built it on a breadboard. It can be directly driven from any domestic 220v ac or 120v ac mains outlets.

The circuit working of this 1 watt to 12watt led driver may be known as presented under. Configured in size and features for mr16 led replacements. I got the concept of this circuit few years back from a led torch which was powered by a single aa battery. To wire a series circuit like the one shown the positive output from the driver connects to the positive of the first led and from that led a connection is made from the negative to the positive of the second led and so on until the last led in the circuit.

Auto detect function allows 12 vdc or 12 vac input while maintaining the targeted output current. You need a constant current for turn on led and this led is power led 1 watt with 3 2 volt. Capacitor need is 5uf 400v but this is very big capacitor and burn after 24h work. Led current in amps 1 25 r3 so for a current of 550ma set r3 to 2 2 ohms you ll need a power resistor usually r3 power in watts 1 56 r3 this circuit also has the drawback that the only way to use it with a micro controller or pwm is to turn the entire thing on and off with a power fet.

Buck boost switching regulator topology. The image to the right shows an example. Good 1w leds are typically 350 ma at 2 9v 1 watt the rest will have higher tolerance on vf e g. The input mains 220v or 120v ac is half wave repaired by d1 and c1.

3 4 running a 3v led from a 12v supply with a series regulator and series resistor is going to be 3 12 or 25 efficient alone. Non isolated constant current operation. Because after work temperate is very hot. And the only way to change the led brightness is to change r3 so refer to the earlier schematic for circuit 5 which shows adding a low high power switch in.

P 1 1 1 25 1 25watts working of led driver circuit. The concept it to try to determine a running current by using the inductor diode and load at the same time the switch fills up the missing load energy on a single cycle. The simple 1 watt led driver circuit buck converter presents approximately 90 efficiency.