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How to connect 25 leds in series?

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shaz

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25 leds in series

hi, how can i connect 25 leds (bright leds) in series so that there brightness is equal. Thnku
 

marie65

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25 leds in series

If the led's are in series it means that the same current pass all of them and will lit with the same brightness. You will need a voltage supply bigger then 25 * LED Forward Voltage, that's around 50 volts
 

Davood Amerion

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25 leds in series

i'd like to add:
If your supply isnt high (>50) you can use parallel/series network to use that with lower voltage.
For example if you want to use 12V battery to turnon LEDs, you can parallel 5 legs of 5 LEDs (in series + current limiter resistor).

for current control you can use 330 ohm resistor for above example.

Regards,
Davood.
 

Sceadwian

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25 leds in series

He said 'bright leds' those are usually white ones, which means the voltage is going to be closer to 3-4 volts per LED. So it may be as high as 75-100 volts. Equal brightness is not possible doing large series strings like this, the brightness will depend on the variation in manufactoring of the LED's.
 

shaz

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25 leds in series

Thanks all of u for replying. i'll try out.
 

shafee001

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25 leds in series

i think parallel is the best connection for those 25 leds, and a series resistance with them, all you care now is power supplay current not volatge with is more easy
 

Sceadwian

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25 leds in series

Yes, parallel is easier, but it also requires 24 more components. Instead of one current limit for the entire 25 led string you need one current limit resistor for each led, that can get bulk FAST.
 

mtkee2003

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25 leds in series

hi
i think if we connect more than 2 diodes in series, then it may be one diode harms.

regards
 

Sceadwian

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25 leds in series

Only if the diodes are badly mismatched.
 

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