All Questions
Tagged with pwm led-driver
76
questions
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129
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How can I properly use PWM to observe hopefully >= 2x normal efficacy, seeing the theoretical max of 1700 lm/W scotopic efficacy?
In a Wikipedia article on "Scotopic Vision", there is a section that states:
The maximum scotopic efficacy is 1700 lm/W at 507 nm (compared with 683 lm/W at 555 nm for maximum photopic ...
- 2,882
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1
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103
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PWM with PIC817 driving MOSFET seems to be too slow (LED dimming)
I want to drive a MOSFET (IRFZ44N) with an optocoupler (PC817) to control the brightness of an 50 W 12 V LED. The PWM is generated by an ESP8266, 1 kHz.
Following schematic is used:
In general it ...
- 57
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24
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Can I use BP2857 constant current LED driver IC with a PWM-controlled MOSFET for dimming and turning the lights on or off with an ESP8266/Arduino?
I am trying to build a remotely controllable aquarium LED light. I live in a country where DigiKey and Mouser are not a thing. Electronic components are hard or impossible to find in this country. So ...
- 23
1
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54
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Driving bidirectional LED Christmas lights
So I bought a set of 500 lights from Temu and noted that they work at 24 V, with half of them lighting up at one direction of current and the other half when the direction is different. There’s only 2 ...
- 145
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46
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Connect LED to current limiter TPS259540 and control the current
I have an LED (ILH-ON01) with a forward current (IF) rating of 1 A. I want to operate this LED at a constant current of 1 A using a current limiter. The current limiter I have has a limit of 1.17 A ...
- 431
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40
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Are there any problems to expect when you add a MOSFET to a DC/DC converter to add PWM modulation for LED brightness regulation?
I need to power LEDs from a solar powered setup with a 12V battery, around 25W of power.
I want to be able to dim the LEDs using a microcontroller.
I was not able to find a reasonably priced DC/DC ...
- 11
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votes
1
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84
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PCA9633 switch high power LEDs
I have been building on of my first PCBs where I want to control a few High power LEDs. The microcontroller I want to use doesn't have PWM outputs so I want to use a cheap I2C PWM pin expander so I ...
0
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1
answer
83
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PWM Generator Array
I want to use an AVR microcontroller to ultimately control an array of RGB 8-segment displays. The only relatively cost effective RGB 8-segment I could find was here,
but it isn't common anode/...
- 437
0
votes
2
answers
166
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How to make an LED current regulator that can be controlled by a Teensy (or an Arduino)?
I need to design a circuit that can control the amount of current that an LED draws (the LED is rated from 0 - 500 mA). The current drawn by the LED should be controlled in the code that the Teensy 4....
- 11
1
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2
answers
152
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Default PWM signal to Off
I have this LED circuit based on the AL8843 chip. The default powered on state is a full blast LED until the STM32 is up and running and sends a low PWM pulse. The AL8843 is set to full power if CTRL ...
- 159
1
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1
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431
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Control high-power LED by LT3080 and PWM
I am a beginner in electronic circuits, so could someone check if my circuits design is correct?
What I want to achieve is as follows;
Light up 5 high-power LEDs (EDC780D-1100)
Vf = 2.1 V
If = 800 ...
- 11
-1
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2
answers
328
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I2C with LED driver doesn't work
I have a circuit with a PCA9635 PWM LED driver. I want to turn on and off LEDs one after another, but my code does not work. I think the hardware is OK. My micro is a 16F887.
Can you help me?
...
- 1
1
vote
1
answer
85
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How to set outputs on a Toshiba TC62D722CFNG shift register LED driver IC
I want to use the TC62D722CFNG shift-register LED driver IC to toggle some LEDs, however, I am having trouble getting the outputs to turn on at all. The IC is capable of controlling the LED current ...
- 341
3
votes
3
answers
204
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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 ...
2
votes
1
answer
155
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Can I use an external MOSFET to dim this high-power LED driver?
I want to use the PAM2861 LED driver.
It can handle my intended load (1 A and two LEDs around 3 V per channel) and I know this because someone with a similar project used it. It's also available at ...
- 141