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Questions tagged [dimming]

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

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1answer
18 views

Dimming LED with speed controller

I'm trying to controll 4 parallel 12V DC LED strips with an speedcontroller. I am able to dim the lights from 100% lit to about 5% lit, but it never turns them off completely. My multimeter can't ...
4
votes
3answers
125 views

How to stop LEDs from dimming in small circuit

I wired up a simple circuit (below) which was designed using the "Every Circuit" website/app. It's a small LED circuit used inside a costume prop. When the master switch is pressed, the 3 LEDs light ...
0
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0answers
29 views

Parallel Triac driving same Inductive Load NOT Working?

As per the schematic two same value triacs and driver circuits are connected parallel, Triacs are BTA24 and Opto-couplers are moc3021 and the load is inductive, when i trigger the MOC U1 the Triac Q1 ...
1
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3answers
85 views

How to improve an elegant design for an LED dimmer, low-powered with LDO

I am building a sunrise alarm clock. The LED is supposed to get brighter over the course of 30 minutes, then remain fully lit for another 30 minutes, then switch off. I am using a digital pin on an ...
6
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3answers
2k views

Does a dimmed LED lamp draw less power than one at full brightness? [closed]

Does a dimmable 6W LED lamp, dimmed to 50%, draw c. 3W? Or does it still draw the full 6W?
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2answers
133 views

How to increase the dimming range of mosfet controlled LED

I'm slowly getting into circuits and I've put together a PWM LED dimmer. The led is driven by this circuit: I'm driving the PWM via a separate BLE device which maps a user input of [0, 100] to an 8 ...
0
votes
1answer
121 views

Constant Current Led Driver (non dimmable) to work with PWM

I have 18W lamps that came with non dimmable led drivers. Ive found datasheet for the main chip (ws3441), which included schematics: and internal block scheme of the chip: I'd like to add dimming ...
1
vote
1answer
163 views

Can a MOSFET be used for dimming instead of switching a LED?

I have a simple circuit that uses a MOSFET to switch on and off a ~100W LED spotlight (30V, 3A). It works for this application. I have been asked to modify the circuit so that the LED can be dimmed ...
1
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1answer
58 views

LED driver type detection- 0-10V or DALI

I am looking for the solution which can automatically detect the driver type installed in street light luminary. There are control mechanism which controls and provides the 0-10V and DALI dimming to ...
0
votes
1answer
148 views

Zero-crossing signal inconsistent timing

I have an ESP-07 with NodeMCU firmware connected to a dimming module with a zero-crossing pin. The current frequency should be 50Hz, which means that the time between two zero crossing should be 10ms,...
0
votes
1answer
121 views

RobotDyn dimmer controlled by ESP 07 only results in flickers

I use a dimmer module connected to an ESP07 which has Node MCU firmware. I'm using the Z-C interrupt to skip sinusoidal pulses, however I only obtain flickering instead of dimming. The light is bulb ...
0
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1answer
105 views

Defining contrast ratio and dimming ratio in a LED driver

I read in this article which analyze the contrast ratio achievable with switched mode LED driver system, that is defined as \$ \frac{1}{t_{on}} : 1 \$. Intuitively I can get that the minimum time ...
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2answers
133 views

Dimming LED based on 12v signal

I've got an LM358 comparator turning on an LED. What I'd like to add is a way to dim the LED by a fixed amound when a 12v signal is sensed. It's in a tach circuit in a car, and when the headlights ...
1
vote
2answers
498 views

How may I select a smoothing capacitor to mitigate LED flicker without the use of a scope?

I recently replaced a set of incandescent bulbs from the interior of my old car with some very inexpensive festoon LEDs. Unfortunately the LEDs are not 100% compatible with the lighting system as ...
0
votes
1answer
279 views

COB LED Dimming via Poentiometer?

I want to create a dimmer for high power LED light's i'm building for video work. I'm using CREE CXB3590 chips, which have run at 36V with a forward current of 3.6A. I am powering these through a 150W ...
0
votes
1answer
247 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'...
0
votes
2answers
61 views

Dimmer buzzing, lights flickering [closed]

Got an issue with my lights and a dimmer. I got a room with 4 lights in it (6W LED panel lights) and a 60-600W dimmer. Somewhy, the lights from time to time flicker and the dimmer is buzzing all the ...
0
votes
1answer
61 views

Driving/dimming/strobing 30 pieces of Cree XR-E individually via Rispberry Pi 3, powered by 18v 4.0mAh makita accu

I am looking for a solution to individually dim (or if not possible switch) 30 Cree XR-E LEDs driven by a 18v 4.0Ah Makita battery and a step-down converter to go from 18v to 3,5v capable of handling ...
0
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0answers
63 views

PWM dimming with ZCD generates humming noise from fan at low speeds

I have created a circuit which implements PWM dimming using phase cutting with Zero cross detection which works well on incandescent bulbs but creates humming noise when connected to a fan. I am using ...
1
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1answer
180 views

Triac misfires because of noise from inductive loads

The product is a wifi enabled smart switching device. One device has 4 different channel for four different appliances to be connected to the product. Each channel has a pair of optocoupler and triac ...
-2
votes
2answers
326 views

High frequency p-channel mosfet pwm dimmer problem

The circuit below is the final one, after all the advice from Mishyoshi and especially Andy aka. It includes Zener diode protection against over-voltage between gate and source on the Mos-fets and ...
2
votes
1answer
431 views

Arduino To Control Light Intensity

So I want to build a circuit that can control the intensity of a light bulb (powered by 220V AC, 60 Hz) through the output voltage of Arduino. I know I must use Triac but the question is, is the ...
0
votes
1answer
43 views

LED dimming and modulating with two PWM signals

I have a need for an LED, driven by a constant current source, that can be smoothly dimmed and also semi-rapidly (say 2.5kHz) modulated for later bandpass filtering. I've designed a possible circuit, ...
1
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0answers
272 views

Best circuit for Zero Cross Detection

I am trying to build an optimal circuit for Zero cross detection for PWM dimming using a microcontroller. I have gone through most of forums and their implementation varies. I understand that the ...
0
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1answer
56 views

4-position touch dimmer - waveforms unexpected, but functional. need suggestions for soft switching

I have a 4-position touch dimmer that is fed with 120VAC line voltage and outputs one of four 120VAC waveforms. The output waveform is input to an electronic transformer labeled to permit "dimmed ...
1
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1answer
606 views

Best Lamp Dimming Circuit? [closed]

What's the best way to dim a lamp, and why? Also, which method is typically used in most typical residential dimmers? I originally thought it was as simple as wiring a potentiometer between the source ...
5
votes
2answers
1k views

Design considerations for LED strip PWM dimming

A note on my background: I'm a programmer in an electronic design company, starting out with hobby projects. I'm planning to design a PWM LED strip dimmer and colour controller for an RGB/RGBW led ...
0
votes
2answers
485 views

Which way I should go, Relay or Triac Switching?

I am developing one consumer product in which I am going to operate Resistive and Inductive loads. In this project there is also a need of dimming of the loads. I have completed programming part. ...
2
votes
1answer
272 views

Need help controlling a relay using a dimming light

TL; DR: Trying to control a relay using a dimming light. When the light is fading on and off, it causes the relay to switch on and off very quickly. Hi all, I am trying to control a relay with the ...
1
vote
1answer
164 views

How does a 120VAC neon indicator lamp respond to a leading-edge triac dimmer?

I bought a dirt cheap toaster oven to convert to a solder reflow station, and I noticed in the teardown that it apparently has a neon power indicator. It goes out instantly when it loses power ...
0
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0answers
98 views

LED flickers below 3%

We are working on an LED dimmer circuit which supports DALI2.0 Interface. We already received the hardware and working on software only. LED driver circuit is based TPS92515HV and below is the ...
0
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1answer
166 views

DALI DAPC OFF command

We are working on DALI LED control gear type product. We are using TPS92515 as LED driver and its controlled through Iadj pin (analog dimming). Our issue is even if we give input zero (GND) to control ...
0
votes
1answer
382 views

Why is this digital potentiometer working?

I've been working on a circuit to dim a Shop Light that according the manufacturer is 0-10V dimmable. Built into the light is an LED power supply that provides two wires, a purple DIM+ and grey DIM-. ...
6
votes
5answers
2k views

Incandescent Light Bulb Soft Start

Is there any circuit to make incandescent bulbs (60-100W) light up more gradually? I've seen many different devices but none of them would work for me. I do not want to just stop the high current ...
0
votes
1answer
56 views

Light fixture dimming, LED turn of

I'm trying to dim a light fixture with the DALI protocol. It functions quite fine but when the dimming gets low two thirds of the LED:s turn of. Why is this? Is it because the voltage forward gets ...
0
votes
2answers
455 views

Dimmable LED lights flashing on full power

This is quite specific but i don't know another site to ask this on. Symptoms: I have a driver that has 3 settings, off, dim and full. The lights turn on and work on dim but on full they flash. ...
0
votes
1answer
293 views

IC controlled triac dimmer design, zero crossing detection and inductor sizing [closed]

I'm trying to create a dimmer that uses an IC to control the triac firing. My understanding is that I need a random phase optocoupled triac driver. However I need to know when the zero crossing is on ...
1
vote
3answers
288 views

Atmega328p PWM overheating and flickering

I'm trying to build a dimming control for a 24V RGBW-LED strip using potentiometers as analog inputs. It's pretty similar to the analogWrite() example on the arduino website (arduino.cc/en/Reference/...
-2
votes
3answers
319 views

Hot Mosfet IRL540N with Gate 5v and Source 12v-260 mA [closed]

I've connected the + of a 12v powersupply to a 12v LED-spot. The - of the LED-spot is connected to the source of a IRL540N mosfet. The drain is connect to the - of the 12v power supply and the ground ...
0
votes
0answers
230 views

FAN Noise with PWM and MOSFET

Objective: Control fan speed with PWM. I am using MOSFET IRF830 with PWM from ATMEL AT89C52. Below is the schematic With this schematic fan makes humming noise at dimming (when not at full power). ...
0
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0answers
40 views

Would increasing regulator rating allow connected components to a system to not cause brownout?

Currently, I have several ICs connected in a circuit to a 6 VDC wall supply through a 7805T voltage regulator. The outputs of the circuit are LEDs and I also have a test point in my circuit in which I ...
0
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0answers
292 views

TRIAC dimmer and bridge rectifier with LED filament lamp

I have a TRIAC dimmer for usual tungsten lamps and LED filament lamp like this one. If i rectify chopped waveform from the dimmer with full-bridge rectifier and smooth the output using a capacitor, ...
0
votes
1answer
653 views

FAN NOISE issue in triac phase angle dimming

I have successfully dimmed a light bulb using a triac & phase chopping method,but when I tried dimming an inductive load (for e.g. ceiling fan) then it made a humming noise at DIMMING, however it ...
1
vote
0answers
896 views

Resistor value selection for PWM dimming of Meanwell LED driver

I'm controlling a Meanwell LED driver's dimming function using 0-5V PWM from an Arduino, stepped up to the 0-10V PWM the driver expects. Here is the circuit. '0-5v' is the 5V PWM from the ...
1
vote
3answers
383 views

How to build a light sensor for PWM dimmed light (for comparison against CC dimmed light)?

I am working on a project in which I need to find a PWM duty cycle to dim an LED to the same brightness level as an LED being dimmed with CCR. Initially, I was considering using a camera for this: I ...
0
votes
3answers
563 views

Driving parallel arrays of LEDs from a single constant current supply

I'm looking at using a single constant current, DC-DC boost converter to power several (6 - 8) parallel strings of 3 LEDs, like the drawing below. This is powered by a single li-ion battery. To ...
1
vote
1answer
3k views

pwm frequency for led dimming

i am using a meanwell LDD-H driver to drive some led for a reef light. (datasheet http://www.kosmodrom.com.ua/pdf/LDD-H.pdf) standing to datasheet i can use a pwm of 100 ~ 1KHz what's the difference?...
0
votes
1answer
46 views

What Wattage does my resistor need to have to be save to dim an LED strobe module?

I want to dim a commercial LED strobe module and can't seem to figure out what wattage the resistor needs to be. Most posts are about single or multiple LEDs with their known forward Voltage etc. like ...
0
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0answers
301 views

How to know if a LED power supply will deal correctly with dimming

I have a led strip with its 24V own power supply (IKEA's Ledberg), and I want to make them dimmable. I've successfully done it with an arduino and a MOSFET, but I'm unsure if the power supply will ...
3
votes
2answers
314 views

Connecting two LED stripts with individual power sources to one MOSFET

I have two LED strips (IKEA's Ledberg white), each with their own 24V power supply and I want to make them dimmable with an Arduino. I was wondering if it is safe to connect both of them (their ...