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    Some LED circuits explained examples from various projects: flashing LEDs, 220V LEDs and more.
    We start by showing you the LED circuit in series with a resistor. You must make some calculations to figure out the resistor value, depending on voltage power supply, LED voltage drop and desired current.

    Series LED circuit

    (Source Voltage – LED Voltage Drop) / Amps = OHMs
    Amps = mA/1000

    Source Voltage = 9 volts
    Voltage Drop = 3.1 volts typical for a blue or white LED
    Desired Current = 13 milliamps

    So the resistor we need is: (9 – 3.1) / ( 13 / 1000 ) = 452 ohms so we will use a 470 Ω resistor.

    220 volt LED circuit

    Caution: Do not try this circuit unless you have good knowledge about electronic devices. This circuit is connected to main power source (220V) and can give you a high electrical shock

    We use one capacitor, a zener diode, a resistor and the LED.
    The capacitors value depend on LED current. With a 100 nF capacitor, the LED current is 4 mA; at 470 nF the current is 20 mA.

    220v led

    Some LED flasher circuits

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    11 Responses to "Simple LED Circuit"

    1. I need mobile phone battery charger circuit with battery over charge protection

    2. Hey Guys
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    3. wat is the size of led used in that circuit of 9 v

    4. so good


    6. what does the zener diode do?

    7. KDS,
      when the current goes way down, (zener in inverse polarity) he keeps constant the voltaje between his terminals (2 volts in the picture) and all the current goes through the LED

      if it goes in the other way, zener diode is in direct polarity and all the current goes through him protecting the LED which is in inverse polarity.

      Please, forgive my english…

    8. Great practical circuits that easy to understand and construct

    9. Great circuit, but what if you’re across the pond and working from 120v instead of 230? What values would change?

    10. i am working on a led project but i dont know about led power.
      i have 100 led bulb of 0.5 watt, i want connect all with power which is use at home.
      can u tell me what type of “resister” use in project…?

    11. Mg Khant Zaw Phyoe says: on September 21, 2015 at 7:46 pm

      Very nice.It is very useful for me.

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