# 20 Watt LED Dimmer Circuit diagram

Discussion in 'LEDs and Optoelectronics' started by Narendrakd, Dec 3, 2015.

1. ### Narendrakd

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Dec 3, 2015
Hi All,

I want to design 20 watt led dimmer circuit diagram so can any one please provide me PCB diagram so that i will make PCB and assemble it.

Narendra

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May 12, 2015

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Dec 3, 2015

4. ### Narendrakd

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Dec 3, 2015
I ried this but the leds are not bright.

All 1W leds are connected to series with 1k register

5. ### Martaine2005

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May 12, 2015
So where and how are the 1W leds connected, and how many?

6. ### Narendrakd

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Dec 3, 2015
The LED icon will be replaced with 20 leds with different board

7. ### Martaine2005

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May 12, 2015
I don't think that will work!
I think you need to design this again including a transistor and powering the leds from 12v rails.

8. ### Narendrakd

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Dec 3, 2015
Martaine can you upgrade the circuit diagram

9. ### Narendrakd

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Dec 3, 2015

Hi Martaine how about above diagram..i think this will also work but when i designed this its working but leds are lit when pots are at mininum level.

so can u upgrade this for better

10. ### CDRIVEHauling 10' pipe on a Trek Shift3

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May 8, 2012
I don't see any LED current limitting resistors in that circuit. Are they integral to the Led array?

Short the Gate to Source to test the FET. The LEDs should turn off.

Chris

11. ### Martaine2005

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May 12, 2015
I think you need to read how to wire leds in series/parallel.
But you have to know the specifications of your leds. Are they 3.5v and 350ma each?
What would be the resistor value?
Would you need 1 watt or 2 watt resistors?
Can you put three or four in series? (12v)...

12. ### Narendrakd

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Dec 3, 2015
Hi this will be in series and less are 1watt each i.e 20 watts.

13. ### CDRIVEHauling 10' pipe on a Trek Shift3

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May 8, 2012
This was Marty's questions:

What does this mean? We still don't know the color of your LED's which dictate their voltage drop. Also, your schematic indicates 24 LEDs ... not 20.

Did you short the Gate-Source to test the FET as I suggested?

Chris

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14. ### Narendrakd

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Dec 3, 2015
see i am new to this and i am trying to make a dimmer led lights for my fish tank so if you guys can send me new diagram with pcb print it will help me lot.

i want to connect 20watt leds on this tank.

15. ### CDRIVEHauling 10' pipe on a Trek Shift3

4,960
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May 8, 2012
Repeating the same requests is becoming tiresome to read. You seem to have an aversion to answering our questions.

BTW, your 25KΩ pot may be too low for the persistence of your eyes to perceive a change in LED brilliance.

Chris

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16. ### Narendrakd

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Dec 3, 2015
so pl draw a diagram for me please

17. ### Alec_t

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Jul 7, 2015
The diagram would need to be based on answers to the questions you have been asked. The ball is in your court.

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18. ### Colin Mitchell

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Aug 31, 2014
Here is the PCB:

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May 12, 2015
20. ### CDRIVEHauling 10' pipe on a Trek Shift3

4,960
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May 8, 2012
Colin, that's a perfect PCB for him. Now he doesn't have to answer any questions and he can fill in the values himself!

Chris

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