Questions tagged [backlight]

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GC9A01 LCD display backlight pwm control

I am trying to design a simple smartwatch using ESP32 MCU. For the display I am using GC9A01 LCD screen like this one. I did get display to work by using prototype board, and now I am designing the ...
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30 views

Driving LCD backlight using boost converter (Feedback loop & Constant Current)

I've been researching LCD backlight circuits (for my STM32-based project), asked questions before, but there is another question I have about the matter. I have noticed that some boost converters (I ...
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1answer
91 views

LCD Backlight control brightness adjustment & cathode pin purpose

I'm working on an STM32-based project to which I'm planning to connect an LCD (in my case, it should be 800x480, specifics irrelevant for the questions). I do have disco development boards with LCDs (...
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3answers
165 views

Transistor with PWM vs LED driver for LCD backlight

I'd like to design a circuit that utilizes a small 1.3" LCD display with maximum LED backlight forward current of 40 mA. Since I'd like to use brightness control, I am hesitating between using a ...
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0answers
76 views

Replacing a 6 V LED backlight with two 3 V LED backlights

I have a 65" TCL TV which have backlight problem and I have another 60" TCL TV with broken screen. Now when I opened both TV to swap with LED backlighting strips, and I and I noticed the 60&...
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2answers
110 views

2.4" LCD TFT backlight current limit resistor

I have some doubts regarding 2.4 LCD TFT ( NHD-2.4-240320CF-CSXN ) backlight current limit resistor value. Datasheet note is not clear 6. Backlight: White LED / 3.1V / 100 mA ( Typ ) 3.1V means: a) ...
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0answers
77 views

How to test TV LED backlight failure [duplicate]

I recently picked up a Braum (Aldi) TV from the nature strip to play around with. The TV seems to work perfectly fine (Channels, DVD input, sound etc) except that there's no working backlight. I've ...
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2answers
165 views

Voltage doubler for LED backlight

I'm sketching out a design for an easily and cheaply built handheld computer based on an ARM microcontroller, and thinking of using a small LCD display. The display has an LED backlight rated for up ...
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1answer
43 views

two PWMs, individual control, 20 LEDs [closed]

Pretty basic requirements: two PWM signals (PWM1, PWM2) 20 individual LEDs sitting behind 20 different symbols (as backlight) normally, when on standby, backlight is 'dim' (PWM1) for all LEDs when a ...
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1answer
126 views

Are my calculations for this LED boost driver circuit correct? (TPS61169)

I have a display with the backlight LEDs arranged 6S4P (so 4 parallel strings of 6 LEDs joined internally, so must be driven as single string) and have been trying to find a suitable driver for it - I ...
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0answers
73 views

TPS61180 backlight blinks once

I received SmallHD 5" display which was broken by supplying 14.4V by a mistake. It runs on 7.2V typically. The monitor is fine, just the backlight went bad. I replaced TPS61180 right off the bat ...
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1answer
703 views

What is the typical voltage for driving LCD fluorescent backlight tubes?

I ran into this old cockpit/pilot room for heavy mining machinery in which there was an LCD display that's not lit properly, that is, the image was there but the backlight clearly was gone. Upon ...
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1answer
109 views

LED backlight hotspot

I have tested a new part number (as replacement) for an LED backlight for an LCD. The LED tested is SML-D15MWT86. We have followed a physical arrangement similar to the original pcb (2 parallel rows, ...
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2answers
236 views

How to calclate Rb value for NPN transistor?

Here is a part of my schematic. K pin from LCD is connected to NPN transistor. A pin is connected to Vcc, 5V. Base is connected to uController. It is Atmega16. 5V supply. I am using BC547 transistor ...
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1answer
103 views

LCD backlight control

I want to connect K pin (or LED-) of LCD to the NPN transitor, so i can control it. The question is how can i calculate resistor value? I found this schematic online, do you think it would work? ...
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2answers
203 views

DPI interface for Raspberry Pi including backlight driver

I am designing a DPI interface for my Raspberry Pi ZeroW. I believe the screen I have is exactly the same as the Pimoroni Hyperpixel 4.0 Square, just without the chunky interface PCB. I have the ...
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2answers
85 views

TI TPS6116 Output Voltage

I am designing an LED backlight driver as a sub-circuit for a DPI interface. The backlight in question requires 12.8V. I am trying to use the TPS61161 and have read through all of the documentation ...
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1answer
125 views

LCD backlight connection, K pin connected only

I have been trying to build the attached schematic, and my issue lies with LCD backlight. The designer has attached the cathode (K) pin, but not the anode (A) pin. This did not work for me. It is an ...
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0answers
250 views

Reverse Engineering a Tamura Inverter Board

This is about the pin-out of 9-pin connector 1 of inverter board Tamura HBL-0291, part of a Toshiba Tecra M2 laptop from the early 2000s (see images). The controller chip on the inverter board is ...
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1answer
431 views

Driving and dimming TFT LCD backlight

I have to add driving/dimming circuit to the design based on NHD-1.8-128160EF-SSXN-F display. The schematics suggested by the manufacturer is practically taken from MIC2289 datasheet (Figure 4-4). ...
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1answer
48 views

Problem with new bicycle front led light and old bulb back light

I had a problem with my front bulb light at my bicycle. So, I bought a new one (LED) for the front, but somehow, the back bulb does not work anymore. I have checked the wires for loose connection, so ...
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1answer
352 views

What is wrong with this LCD backlight boost converter circuit

I have been working with a dev board with the LCD backlight circuit shown below. The boost converted used is the TPS61041. On page 18 of the datasheet, there is an example of the backlight circuit ...
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1answer
79 views

In LCD/LED displays, does the back light strobe or remain on?

In LCD/LED displays, like the ones used with computers or for watching TV channels. Does the back light strobe in sync with the refresh rate or does it remain on all the time?
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1answer
2k views

How to find replacement LED for TV backlight

My TV has a damaged LED in its backlight. The LED had started flickering like 2 weeks ago and finally the whole backlight stopped working. Nothing obviously unusual on the LED driver board, the MOSFET ...
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2answers
678 views

Trick monitor into receiving signal [duplicate]

I have the plan to convert a few old LED backlit monitors into false windows. While I theoretically could buy direct LED drivers to power these panels, I'd prefer to keep the existing circuitry, since ...
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1answer
269 views

LED-drivers FAN5331 and FAN5333

I have a question about the following LED drivers: FAN5331, datasheet http://www.mouser.com/ds/2/149/FAN5331-92198.pdf FAN5333, datasheet https://www.onsemi.com/pub/Collateral/FAN5333B-D.pdf They ...
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2answers
262 views

Light sensors sensitive enough to detect for PWM from CF and LEDs?

I have an extreme sensitivity to PWM light sources such as computer screens and light bulbs. This can make it very challenging to make a purchase as I end up having to do lots of guesswork with ...
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1answer
90 views

(Backlight) LED Driver maximum number of LEDs

I've been tasked to find a suitable backlight led driver for a Mitsubishi LCD panel (AA104XF12-cf1) which is PWM dimmable, but in my search I've only found confusion. In nearly all datasheets it ...
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2answers
1k views

LCD Backlight Control Circuit

I'm trying to control the back-light of a TC1602A-09T 16X2 Character LCD by using an output pin on a Teensy 3.2 microcontroller. This is the circuit I have at the moment: The LED- pin would be ...
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2answers
3k views

Is the voltage supplied by an LCD backlight inverter in a laptop dangerous in any way?

It is my understanding that in a laptop, voltage from a low voltage (say 10V) battery can be converted into higher much higher voltages by way of inverter for an LCD display module. Is this voltage ...
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2answers
2k views

Laptop keyboard backlight ribbon cable broken [closed]

I've accidentally broke my laptop keyboard backlight ribbon cable when disassembling my laptop. I want to solder it back by patching with copper wires or maybe copper plates. My question is, it is a ...
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1answer
69 views

LCD module with backlight

I am using COG-C144MVGI. I am trying to turn it on with my Raspberry Pi. I am not sure if I am following the "power on sequence" correctly. Does this kind of LCD modules work without backlight? I am ...
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1answer
270 views

Do cold cathode fluorescent lights (CCFLs) degrade as a function of idle time?

I have a HP LP2475w display with a cold cathode fluorescent light (CCFL) backlight. It is approximately 8 years old. However, it has only 9041 backlight hours, meaning it has been used for only 12.9% ...
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1answer
1k views

Backlight dimming Innolux at065tn14 with vs-ty2662-v1 (PCB800099) LCD driver board

I would like to dim an Innolux at065tn14 LCD backlight via an PWM signal generated by an arduino pro mini. The driver board has an pt4103 Step-Up Converter to drive the backlight of the LCD display. I'...
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2answers
139 views

Which things should I have in mind when choosing LED backlight frequency in range 10 kHz to 100 kHz?

So I have a display which has an integrated LED driver for backlight. The driver expects PWM input with frequency between 10 kHz and 100 kHz. The only other information I have are the maximum voltage ...
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1answer
197 views

Driving LCDs with parallel LEDs in singles

I am implementing a LED driver for a LCD that has the particular arrangement of the backlight LEDs shown in the picture bellow, 4 parallel LEDs. It seems quite inconvenient not to have them in a ...
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1answer
2k views

LCD 16x2: circuit to adjust the LCD backlight by a PWM signal

I am testing a lcd 16x2 whith msp430g2553. I am controlling the backlight by PWM signal. I am using the P2.4 as output generating a PWM signal. I have connected the anode directly to pin P2.4 of the ...
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1answer
57 views

Switching backlight to RGB in the following monitor C24FG70

I have the following monitor: Samsung C24FG70. Is it possible to change the white led backlights with RGB leds? Possibly the smd APA102 with the following microcontroller: ESP8266. How could i hook ...
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1answer
1k views

Philips 26PF5321 backlight mod, dim backlight

Got this older Philips 26PF5321 LCD-TV, like it because it is not a smart-tv. What I dislike about this TV is the fixed backlight setting (cannot change it via software menu and there is no update ...
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2answers
614 views

Can't understand where backlight pins are in this LCD module

I have this LCD display: RC0802A-BIW-CSX It is supposed to have a backlight, but I can't understand where the backlight LED is since the connections are just 14 pin, and backlight is not mentioned. ...
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1answer
101 views

Microwave lcd display works but lost color.instead numbers are now greyish. [closed]

Microwave is completely usable. And still goes to sleep to power save after some time. Problem is although display updates and works as it should...the values are now shown in a greyish color instead ...
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1answer
3k views

Vee negative voltage output LCD

I have a LCD i want to use for a project but still can't get it working on a breadboard. I have used LCD's before so I'm familiar with them, this one however has something i haven't seen before. ...
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3answers
413 views

Drive backlight LCD led

I need to drive LEDs in LCD backlighting. My LED are in this circuit: The backlight needs a current of 700 mA at 9 V. What driver should I use for control? According to the current peak calculation ...
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2answers
5k views

What is the purpose of the diodes on a Samsung LED TV backlight bar

Skip to the question below if you don't care about the details ;) The bottom half of the backlight in my TV went off so I opened it up to see if I could fix it. I found four of the 7 bars of LEDs ...
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1answer
57 views

Sensitive instrument 5 V needed

I need advice on powering a STN-display module. I am confused on getting the correct power source for the backlight. The backlight of old module (SP12N002) contained CCFL and new (SP12N01L6ALCZ) is ...
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1answer
517 views

TFT backlight control via GPIO

I need to control TFT backlight via single GPIO output from atxmega128a4u. The LCD backlight requires +3.0V, while the rest of my schematic runs on +3.3V. I do not have access to backlight ground pin,...