Questions tagged [dimming]

'dimming' is the action of reducing the amount of light emitted from a device.

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Dimmable lamp forgets its settings when turned off [closed]

I've bough these lamps: lamp 1, lamp 2 After turning the light off with the switch, not the remote control, my lamp forgets its color, brightness settings. Plus it turns on with a random color/...
Ferenc Dajka's user avatar
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Estimating apparent LED brightness: current or power?

TL;DR - based on the physics of LEDs, does current or power give a better estimation of actual light output of an LED? I am building a dimmer circuit with a few discrete steps, to operate a COB LED ...
JAE's user avatar
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PWM with IN-12 nixie tubes [duplicate]

I have some IN-12 nixie tubes and I can drive them using TPIC6B595N chip which has 50V clamping. And this chip has G pin which it is possible to use global dimming. What I questioned is which PWM ...
enis's user avatar
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Does the “non-dimmable” in “non-dimmable LED driver” refer to input, output, or both?

When an LED driver is described as “non-dimmable”, does this mean that only the input power must be constant, or that both input and output power must be constant? Disclaimer: I’m not an electrical ...
Alex Peters's user avatar
1 vote
2 answers
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Why are most of the LED lights for living dimmable just by their remote (they do not work with a wall dimmer)

I am trying to replace the lights in the entire house with LED lights with a more modern style like this one https://www.amazon.ca/dp/B09582MM2J. They all use LED strips and they say they are not ...
MiniMe's user avatar
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MOSFET between LED and driver for PWM dimming?

So I found a lot of cheap nice LED lamps with some generic cheap non dimmable LED driver. I like dimming. The LED is something like 18 V, 250 mA. Could I stick something like an ESP32 with a MOSFET ...
Moritz von Schweinitz's user avatar
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Dimmer with 2x MOSFET + isolation

I'm working on a test schematics for LED dimmer with MOSFETs rather than TRIACs. Some part of the schematics (MOSFET part) is taken from various websites, but combination below was never seen as a one ...
unalignedmemoryaccess's user avatar
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TRIAC dimming using MOC3021 with two or more lights are connected, in off condition lights is some blow

In this dimming circuit I'm using BTA41/BTA16/BTA39 and MOC3021. There is 1 light is dimming is running smoothly, but when 2 or more light is connected, in off condition lights are blowing dim. Where ...
Jaimin's user avatar
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How does one dim very high LED loads with PWM?

Suppose we take a LED source that can be dimmed using PWM (i.e., by turning power on and off at high frequency). Dimmers exist for these sources up to, say, 5A at 24V. But what if I want to dim 10x ...
Dmitri Nesteruk's user avatar
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Difference between analog dimming and digital dimming an LED [closed]

I would like to understand the difference between analog dimming and digital dimming in LED drivers. I went through this article where there is some difference indication on page 4, but I'm still not ...
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Change LED dimmed signal to full power when turned on?

Here's the scenario... EDIT: Everyone seems to so far be missing the part about ELIMINATING the dimming, first and foremost. I have a 12v circuit that is powering an LED array. On some event, the ...
Konfucius's user avatar
2 votes
2 answers
519 views

Dimming an LED with a capacitor across it

I want to dim my ceiling LED light. I disassembled it, and it turns out that this is a led strip with many leds in serial. Its power supply is a 40V 450mA one, and I have built a circuit that could ...
tvili999's user avatar
1 vote
1 answer
51 views

LED light works with one power supply, but not another

Here's the situation: I bought some cheap LED pot lights off of Amazon to use in a project. These pot lights take 120VAC input, run it through a rectifier, and output 5VDC or 34VDC (depending on the ...
tripleblep's user avatar
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Inline dimming circuit fed from dimmable lighting controller

I have an industrial dimmable lighting controller (240VAC, 50Hz) which has one output going to a splitter cable with multiple connectors, where many dimmable LED tubes can be connected. I would like ...
weblar83's user avatar
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Using long button presses to vary duty cycle of 555 (instead of potentiometer)

Apologies for poor phrasing and structure, this is my first post. I am trying to learn how to implement 555 to create a PWM with variable duty cycle (for control of LED brightness) Rather than the ...
bertie pleass's user avatar
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Reducing light dimming when AC units urn on

Currently I use two 60 W incandescent bulbs and and a standard rotation dimmer in the office. When the A/Cs turn on on the 2nd floor these lights dim significantly and sometimes turn off. All wiring ...
Bob M's user avatar
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Is there anything to limit LED output dimming 50% while the wall dimmer controls 50% to 0%?

We got a project for a client but our lights are too bright for the space, we still want to sell the the lights because we have extra inventory and need a way to dim the LED output to 25W instead of ...
VV1993's user avatar
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3 votes
2 answers
353 views

How to drive multiple floating N-channel MOSFETs

I want drive a RGBW-LED (CREE XLamp XM-L) using a synchronous constant current buck. To control the brightness and color, the LED of each color channel is controlled by a shunt transistor using PWM. ...
Michael's user avatar
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1 answer
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Nixie anode transistor dimmer

I'm working on my nixie clock (IN-14) and I am stucked on one problem. When I tried to dim my nixie tube through transistor on cathode, everything works fine. simulate this circuit – Schematic ...
Antaury's user avatar
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noise based dimming of an LED

I am thinking about building a dimmer for an LED that does not use PWM. My idea is to use a white-noise-signal and switch an LED on (or off) depending on whether the signal is above or below a certain ...
exocortex's user avatar
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Why is the transistor in this dimming circuit getting very hot?

This is a fairly simple dimming circuit using a dual opamp (IC1) as a comparator to control the brightening and dimming of a light bulb. The switch (pin 2 IC1a) is a contact connection to ground. ...
Fid's user avatar
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Need advice on an LED dimmer 0-10 V circuit

I've setup a small system where I can control a 6 W LED. I change the brightness of the lamp by adjusting the signal 0-10 V. Diagram (2) is the waveform while connecting with a phase-cutting dimmer ...
lupinn's user avatar
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How to limit voltage to microcontroller, and drain the rest?

I am designing a circuit to control a set of 0-10v dimmable lights. The lights have two lines, Dim+ and Dim-. Dim+ will be at 10 volts, and the brightness is controlled based on how much is drained to ...
Lukeduke Animations's user avatar
1 vote
1 answer
210 views

I don't understand dimming on 3 quadrant TRIACs

Can someone help me understand how dimming works on 3-quadrant triacs? I understand they are great because they have higher reliability and don't need snubbers. What I don't understand is how 0-100% ...
humanistscience's user avatar
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1 answer
99 views

Phase cut dimming driver for panel lights having occasional flick

I am designing a phase-cut dimming driver for Incandescent bulbs as well as LED panel lights with dimmable drivers. Using a BTA24 Triac and VOT8121AB Optocoupler driven by my MCU. For zero-cross ...
Daga Arihant's user avatar
1 vote
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115 views

Uneven Brightness Curve When Using Digital Triac Dimmer on Neon Transformer

I am working on an AC dimmer project using the following circuit: This circuit functions by detecting zero crossings in the AC power input via the LTV814 optocoupler connected to a pull-up input pin ...
Emmett Palaima's user avatar
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137 views

RC PWM question - dimming LEDs

I have some automotive LEDs that I put onto an RC car. I use the RC car's 4S LiPo (14.8v) to power the LEDs and they are great. I use a hobby PWM relay board to turn them on and off and that's slick; ...
Joseph Shmoe's user avatar
1 vote
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107 views

LED driver/analog adjustable constant current source with constant output without PWM switching?

I am using 3 halogen lights with 5V/0.5A each controlled by a constant current source (or basically "LED driver") because of light accuracy. Right now I am using the PT4115 (step down led ...
Dakalaom's user avatar
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Dimming energy with load cell

I'm a lawyer with no technical background. I'm just a geek! :D I wonder if it is possible without using a micro controller can a load cell dim the amount of energy supplied by a 3V battery? The ...
lelot's user avatar
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Is there a way to dim CCFL lamps in a monitor backlight?

I use 30 inch monitor Samsung 305t that uses 16 CCFL lamps as a direct backlight. The driver consists of 8 HV transformers, each of them running 2 lamps in series. Some info about the lamps: As you ...
Komental's user avatar
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1 answer
534 views

How does amplitude dimming (CCR) work?

When a LED driver dims using constant current reduction (CCR), what voltage and current is sent to the LED chip at the various dimming levels? Say I have a CCR-compatible LED chip which takes 500mA ...
hfossli's user avatar
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Can a Triac be driven using only positive voltage due to the laws of Q1 and Q4 quadrants?

I have a BTA12-600B Triac and an Arduino. Is it possible I can trigger both positive and negative amplitudes of an AC cycle by suppling only a positive voltage from the Arduino digital pin to the ...
S To's user avatar
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3 votes
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How to prevent LEDs from flashing when turned ON

I have a custom board to control multiple high-brightness strip LED (ON/OFF and dimming through a potentiometer). Into this board, I have some strip LED that are continuously ON (only dimmable) and ...
vionyst's user avatar
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MeanWell PWM dimming

I have similar situation, described here: MeanWell 3-in-1 dimming So, I need to control MeanWell power by PWM signal from Arduino. I tried to simulate scematics, given as answer in that topic, but it ...
Alex's user avatar
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4 votes
2 answers
759 views

Getting problem in triac based fan speed control

I'm using this circuit to control the speed of ceiling fan. The fan speed is divided into 8 steps. (0:off & 8:full speed) with 100us gate pulse. This circuit works with incancescent light bulb ...
mastermind's user avatar
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1 answer
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Trailing edge dimmer circuit limitations

I just came across this circuit meant for trailing edge dimming of LED bulbs but I was wondering what else could it be used for and what its limitations are during general use. To my understanding by ...
B. Ueno's user avatar
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Advice on controlling an unknown dim-able 12V LED

I have been controlling "5050" RGB LED strips from the GPIO of a Raspberry pi with a simple circuit using mosfets. This is the guide that I followed: https://dordnung.de/raspberrypi-ledstrip/...
sebinho's user avatar
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is connecting high end high power leds in series feasible and are there light quality or other issues

i'm building high power high CRI cine lighting mostly to illuminate softboxes and have chosen Cree XLamp CMT2850 LED 1400mA 36V (Fidelity 95plus CRI). I plan to build about 12 units for the studio. I ...
stevesnowsurfer's user avatar
1 vote
1 answer
39 views

Step up regulator with fading input

I have an input power source that fades an LED on and off smoothly, from 0 volts to 7.5 volts. I would like to use a 12 volt LED. I have been looking at step up regulators which look suitable for ...
Mark Tickner's user avatar
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4 answers
596 views

Powering 12V 35W halogen bulbs with a constant current supply

I'm revisiting an old project, and I want to see if there is anything I could have done differently, or if I missed any important details or considerations. Basically, I used a constant current driver ...
NuclearDude's user avatar
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How is Gate Trigger Current determined in a "dimming" circuit?

EDIT: DIAC part numnber is DB3TG I'm trying to understand how a dimming circuit works, specifically TRIAC control. The TRIAC (D1) in this circuit is a BT136S-6. Where does the Gate Trigger Current ...
Craigfoo's user avatar
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1 answer
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Christmas LED dimming circuit with potentiometer

I need help. I would like to dim LEDS of a Christmas tree with a potentiometer. Here is my electric diagram. (Please note I'm a beginner in electronics.) I don't know how to choose a good value for ...
Cypf's user avatar
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4 votes
2 answers
428 views

Can this WWII era rheostat be modified to dim an LED bulb?

I have a WWII era RAF chart-board lamp in perfect unused condition. I want to use an LED bulb with the original dimmer as tungsten runs so hot. I want to avoid rewiring or bypassing the dimmer as the ...
Walter Hutton's user avatar
3 votes
4 answers
2k views

How to dim one of these cheap 5mW laser modules?

I used to have an old 3x LR44 lithium cell laser pointer for presentations. With the batteries slowly dying, the outputted beam also went dimmer. Recently I bought one of these cheap 650nm laser ...
isync's user avatar
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1 vote
2 answers
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How to adjust the brightness of a small LCD(21V) with a potentiometer?

I want to adjust the brightness of a small LCD with a potentiometer. How can I use a 555 timer to make a PWM which can give out an output of 21V from a 5V input?
T.J's user avatar
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2 votes
1 answer
1k views

Why does color of addressable RGB LED strip change when dimming?

TL;DR I have an addressable LED strip with TM1814 IC's. (So it's actually a RGBW strip. Download datasheet here.) When set to orange at full brightness, it's orange. But when set to orange at 10%, it ...
empewoow's user avatar
1 vote
2 answers
805 views

Meanwell Led driver: internal 3-in-1 dimming circuit

In Meanwell led drivers like the ones from the XLM, HLG or LCM families, how does the internal circuitry for the 3-in-1 dimming feature (0-10V, 10V PWM, 0-100kOhm) look like? I use a LCM-25 in my ...
Sim Son's user avatar
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1 vote
2 answers
177 views

Pulse Dimming to 1-10V

I have a question about the dimming of Led drivers. I have a lot of LED drivers which can use pulse dimming or 1-10V dimming. One problem I have is that I realized too late that by using pulse dimming,...
Ciaran Lichtenberg's user avatar
1 vote
2 answers
918 views

Adjustable current source 0-20mA for LED dimming

I have been searching through the site, but I have not been able find an answer. I have an LED (rated for 14 mA at 24V, the LED is with built-in series resistor) that I need to be able to dim from ...
Lunde's user avatar
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1 vote
2 answers
511 views

Building a passive Dim-to-Warm LED array

I have started a project for my home lighting, I'm trying to build a DC LED module which would change the color temperature from 3000K to 1800K as dimmed with reducing current. I'd like to do it ...
Ömer Gezer's user avatar