Need Help for Voltage and Current circuit for High Current LED devices

audioguru said:

Have you looked at the datasheets for the transistor and the Mosfet to see which pin is which?

Click to expand...

Not yet, i'm still searching for MOSFET in my place because it's hard to find, i try to search IRF540or something better..

ronsimpson said:

**broken link removed**

Hopefully this link will work.
Power supply:
Vin 7-35 volts
Vout 1.25 to 30 (as long as vout is less than vin )
Current limit 0-3A. It states you need to add a heatsink at 3A level.

Set the voltage too high by a little. Set the current limit to 1A or something reasonable to start out at.

This switching power supply should generate much less heat than the linear regulator.

Really big version:
**broken link removed**

Click to expand...

Thank for suggestion, but i decide to make my own circuit, rather than buy ones, for educating my knowledge and skill for electonics system.
i just want to know that. thank you.

yesterday night i have built one circuit from MikeML and try to compare that circuit between D.I.Y one and 3A LED Driver from china, and have this comparation :

D.I.Y Circuit = Amperage can drive to 1.57A (from Digital Ampere Meter) running in 12,5V Source.
China Driver = Amperage can drive to 1.22A (from Digital Ampere Meter) running in 12,5V Source.

But, the Brightness between both circuit is different, my D.I.Y Circuit is like only 80% brightness from Built in LED Driver.
where the current of D.I.Y Circuit is Larger than Driver, whether if D.I.Y MOSFET goes Heat up then the Brightess of LED is down?
my friend say that LED Driver circuit have internal Feedback correction rather than D.I.Y Circuit?

please give me any suggestion again.. thank

In MikeMl's circuit the 2N3904 transistor (that is sensitive to temperature changes) and the 0.33 ohm resistor set the output current. Conduction of the Mosfet is controlled by the 2N3904 transistor. The Mosfet is simply a voltage controlled resistor.
When the Mosfet heats up then nothing changes in the circuit because it is controlled by the 2N3904 transistor.

Since you did not post the schematics of your DIY and Chinese circuits and you do not show how you measured their currents then we cannot make suggestions about them.