Anonymous
Anonymous asked in Science & MathematicsEngineering · 1 month ago

Is there an electronic circuit that will make an light emitting diode have a glowing effect, and not just steady on, like a fast pulse?

3 Answers

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  • 1 month ago

    Yes, You can drive an LED with an Oscillator and driver circuit.

  • 1 month ago

    the intensity of an LED can be easily varied by applying a pulse train with variable duty cycle. Keep the frequency high enough and the flickering would not be visible to the human eye.

    you can use a 555 IC, get the datasheet for circuits.

  • Dixon
    Lv 7
    1 month ago

    To vary the brightness you just need to vary the voltage across the LED and its current limiting resistor. If you want it always on but also pulsing you would have a steady DC feed and then add in an AC signal, probably a sine wave. 

    To make a sinusoidal voltage you could use some sort of oscillator. My inclination would be to use a cookbook op-amp oscillator and sum that with a DC signal in an (inverting) op-amp adder. Using variable resistors it would be relatively easy to vary the amount of sine wave and DC  added together in order to produce the effect you want. A typical op-amp such an  LM 741 might need an emitter follower (BC107) stuck on the end to boost its current drive depending on your LED.

    The circuit below is just a quick idea and totally untested. I haven't included the details of the oscillator but Google should give you any number of circuits for that, or indeed the LM 741 data sheet.

    Attachment image
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