### Author Topic: NHD-24064WG-AYYH-V Backlight current  (Read 4861 times)

#### sergef

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##### NHD-24064WG-AYYH-V Backlight current
« on: May 18, 2016, 06:04:38 AM »
I've been looking at the datasheet of the NHD-24064WG-AYYH-V display and the backlight current (660mA) seems to be very high compared with other similar displays (about 100mA).

I want to use a voltage regulator to supply 4.2V but I can't find one who can handle 660mA that needs the display.

It's correct the data of 660mA shown at the NHD-24064WG-AYYH-V datasheet?

If yes, It's possible to connect the backlight display directly to a 5V Power supply?

Sorry for my poor english. I hope you can understand my doubt.

#### Saurabh_B

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##### Re: NHD-24064WG-AYYH-V Backlight current
« Reply #1 on: May 18, 2016, 08:33:53 AM »
Hi,

If you were to use a current limiting resistor in series with the backlight pins you can apply 5V directly to the backlight.
I would recommend using a ~1.2Ω resistor for this.

#### sergef

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##### Re: NHD-24064WG-AYYH-V Backlight current
« Reply #2 on: May 19, 2016, 05:46:42 AM »
I guess you want to say 1K2 ohm resistor (brown - red - red - gold/silver)

I'll try it if you confirm me that issue.

#### Saurabh_B

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##### Re: NHD-24064WG-AYYH-V Backlight current
« Reply #3 on: May 19, 2016, 08:08:22 AM »
No, you would want to use a 1.2Ω resistor. A 1.2KΩ resistor would result in a very dim backlight.
For a current limiting resistor you would want to do the following = (Vin - VLED)/(ILED)
(5-4.2)V
0.660 A

Which would leave you with ~1.21Ω

« Last Edit: May 19, 2016, 08:21:01 AM by Paul_B »

#### sergef

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##### Re: NHD-24064WG-AYYH-V Backlight current
« Reply #4 on: May 19, 2016, 12:44:08 PM »
OMG!!! Basic Ohm's Law

How I didn't think it before? I feel like a fool

Thank you very very much

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