Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [backlight]

54 questions
3
votes
2 answers

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 to 80mA with a typical \$V_f\$ of 3.2V, though a…
Mike Spivey
  • 612
  • 5
  • 12
3
votes
1 answer

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 wondering if I am supposed to get some kind of…
user167987
  • 119
  • 9
3
votes
2 answers

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. Any idea?
Felice Pollano
  • 853
  • 9
  • 20
3
votes
2 answers

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 were not working and narrowed down the problem to one…
Amrit
  • 31
  • 1
  • 3
2
votes
3 answers

Purpose of resistor in inrush current circuit for MIC2289C LED driver

I am looking to use the MIC2289C LED backlight driver from Microchip in a circuit and have a question about the unnamed resistor that connects to the FB pin of the driver and the cathode of the LED string. Does anyone have intuition why it is there…
jakob
  • 462
  • 3
  • 12
2
votes
1 answer

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 thought the TPS61169 looked promising but now…
John U
  • 7,041
  • 2
  • 21
  • 34
2
votes
1 answer

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, with 4 LEDs per row distributed symmetrically…
user139731
  • 391
  • 3
  • 13
2
votes
2 answers

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 cameras and other methods to try and identify whether…
Zhro
  • 2,875
  • 4
  • 17
  • 31
1
vote
0 answers

Transistor choice for PWM controlled LCD backlight

I have a problem with choosing most appropriate transistor to control backlight of my LCD display. According to datasheet its \$I_f = 60mA\$, and \$V_f = 3.2V\$. My circuitry is all 3.3V based. I want to supply PWM signal from my STM32 F411CEU6,…
Andrzej Komor
  • 21
  • 2
1
vote
1 answer

Can you damage LCD backlight when you frequently turn it off and on?

I have this small project with PIC microcontroller and LCD display WH1602A-TTI-ET. I am controlling the backlight via software, so I attached it to +5V via PNP transistor that is controlled by one of the pins of the PIC microcontroller. The problem…
Petr
  • 487
  • 5
  • 11
1
vote
0 answers

Significance of LED number in selecting inductor and capacitor values in backlight driver circuit

I am looking to configure an LED backlight driver circuit and had a couple questions I was hoping I could find some answers for. My application is a TFT LCD screen with a single anode/cathode input with two parallel strings of 9 LEDs that are in…
jakob
  • 462
  • 3
  • 12
1
vote
1 answer

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 (F746 and F469), but I have never integrated…
Ilya
  • 3,478
  • 7
  • 33
1
vote
0 answers

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" TCL is fitted with 6 SMD with 3 V LED and 65" TCL is…
Singh
  • 11
  • 2
1
vote
0 answers

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 but this didn't fix the issue. Right now I'm getting…
Maciej Kobus
  • 43
  • 4
1
vote
1 answer

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 old schematic, and is designed for an LCD with…
Ben Rosser
  • 13
  • 3
1
2 3 4