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LED Dimmer circuit needed Answered

LED dimmer circuit please suggest me a good one,my LED is CREE XML LED voltage ratings is 3-3.5V and current ratings is 0.7-3A.Input should be 5Volts.
It should have a variable resistor with switching function.ON/Off potentiometer.
Your early response is welcomed!.?



6 years ago

Here is a nice circuit using the LMR10520 simple switcher using a
5K pot to adjust the LED current from  700ma up to 2000ma ..  .  A


Thanks for reply,it their any other IC with DIP package for dimmer function.
Kindly let me know what changes are required for a 555 timer circuit if use as a dimmer.

Kindly let me know if i want to drive the IC with a 5V,3A adpater then what changes are required in circuit like can i use TIP 122 NPN,what diode should be used that is easily available like(1n4007) what should be the value of potentiometer then.And any change in other values of circuit.

That is a high power led. You'll want a current controlled driver - and if you want dimming, you're gonna want a specific driver board. They aren't expensive, 5-10 dollars, and they ensure you can use whatever battery type is appropriate;

Search for flashlight led driver and you'll find tonnes on sites like ebay and dealextreme.

I know it's not a 'put it together' option, but there aren't good portable, dimmable high power led drivers for the layman.

There is a dimmer cct here using a 555 timer

Thanks but if a single LED is to driven and it's current is hihger so what should be the transistor used.
Also if the 555 timer is given 5volt then will this circuit works.