outdoor garden solar lights

Outdoor Garden Solar Lights Circuit

This Outdoor LED Solar Garden Lights project is a hobby circuit of an automatic garden light using a LDR and 6V/5W solar panel. During day time, the internal rechargeable 6 Volt SLA battery receives charging current from the connected solar panel through polariy protection diode D9 and current limiting resistor R10. If ambient light is normal, transistor T1 is reverse biased by IC1 (LM555).

LED Solar Lights Circuit Schematic

outdoor garden solar lights circuit schematic

Here IC1 is wired as a medium current inverting line driver, switched by an encapsulated light detector (10mm LDR). Multi-turn trimpot P1 sets the detection sensitivity. When ambient light dims,transistor T1 turns on to drive the white LED string (D1-D8). Now this lamp load at the output of T1 energises. Resistors R1-R8 limits the operating current of the LEDs. When the ambient light level restores, circuit returns to its idle state and light(s) switched off by the circuit.

Assemble the Outdoor Solar Lights circuit on a general purpose PCB and enclose the whole assembly in a transparent plastic box. Drill suitable holes on the top of the encloure to mount the mini solar panel (SP1) and the light sensor (LDR), and in front for fitting power switch (S1) and the sensitivity controller (P1).

Fix the battery inside the cabinet using a double-sided glue tape/pad. Finally, the LDR should not be mounted to receive direct sunlight. It must be mounted at the top of the enclosure, pointing to the sky say southwards. This circuit is very simple. So interested and experienced hobbyists can alter/modify the whole circuit as per their own ideas without any difficulty (Just try a 6V relay with T1 to drive more number of LED strings)


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  • Datt Nanaware

    dear sir please send mi 6v/13.5Ah Battery ,176 Nos Super Flux Led,solar street Light simple Dusk to Dawn circiut Diagram Pz Sir.
    I am wait for your Replay.

  • teja

    how to arrange the circute on breadboard sir

  • Tony

    I am attempting to learn electronics on my own. Can someone explain how an IC that is known to be a timer can function as a “medium current inverting line driver”, whatever that is? I have looked at the data sheet and do not understand this usage.
    Thank you,

    • Jim Keith

      There are many ways to apply some IC’s and that can be confusing to the novice. I do not agree with Mr. Hareendran’s description: “line driver,” so you may put that to rest. A line driver usually drives a data transmission line, and this is clearly not the case here–I suppose the 555 could perform that function under certain conditions, but I had never thought of doing so and I have never seen it.

      What I have done with the 555 is to use it as a schmitt trigger inverter driver as Mr. Hareendran has done here. This is undocumented as are many 555 applications. When the input voltage gets above 2/3 Vcc the output goes low, and when it goes below 1/3 Vcc the output goes high. Output drive capacity is capable of driving R9, a 220Ω base current limiting resistor.

    • Tony

      Thank you for your prompt answer.

  • Hristo

    Hi all! Can somebody tell me what is the purpose of this resistance R10 – 15ohm / 10W

    • P. Marian

      “During day time, the internal rechargeable 6 Volt SLA battery receives charging current from the connected solar panel through polariy protection diode D9 and current limiting resistor R10”

  • sebastian

    Seems to use a lot of power as there is only a single LED in the string.

    Adding two LEd’s in the string and reducing the resistor value would increase the battery life by 40%


    Hi SIR,

    i am electronics gagets enthusiast and i want to make a garden solar automatic light with charge controller for overcharge and battery discharge protection supplied by a 9 volts or 12 volts battery..please sir can you help to make this circuit by sending me a circuit diagram along with necessary components to my email ID :

  • AsiF

    This Circuit is 100% working… I m doing a project on this circuit…
    U can also follow the link below for Solar Controller:


    pl. issue me 5w led solar light cercuit

    and 2nd,
    issue single wt.led cercuit using 5252 f/1004

    thank u

  • Haslan

    hi sir…

    can u give more information about the solar panel. thanks.

  • Paul

    The resistors in serie with the LEDs will dissipate 40 mWatt each. It is more power efficient to limit dissipation by.

    1) using 2 LEDs in serie
    2) let the LEDs light with a 200 Hz current.
    3) using a current controlled circuit based on switching technology as used in switching power supplies.

    Disadvantage of no. 2 is it complicated schematic.

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