AC-LED Night Lamp




Introduction: AC-LED Night Lamp

About: Now I am a retired person, who enjoys life and making small things to pass the time keep myself busy.


This AC LED Night Lamp is dedicated to my friend and adviser *qs*. Without his help I could not have done it.
This Night Lamp runs on AC and is also a Emergency Light when run on the UPS of your PC. during power cuts.

Step 1: STEP-1


First of all we will fix the LED's to the Perforated Hard Board.
Fix a row of 5 Blue LED's each on both sides of the Perf Board.
Then fix 6 rows of 5 White LED's in between the rows of Blue LED's
That is in total 10 Blue LED's and 30 White LED's = 40 LED's.
After fixing the LED's to the Perf Board we will wire the Circuit.
Please see the next Photograph for guidance.

Step 2: STEP-2


Follow the Circuit as per the Diagram, The Circuit diagram is very easy to follow as it shows all the polarity of the LED's clearly.
The step down Transformer is a 220 volts to 12 volts. AC.
Blue and White LED's working voltage is 3.3 volts.
Therefore 12v X 1.4 = 16.8 divided by 3.3 = 5.090 so I have taken 5 LED's per row.
This is as per the calculation of my friend **qs** in his Instructable AC with LED's.
A change over SPDT switch is connected for Night lamp (Blue) and Emergency Light (White)
Care should be taken to keep the POLARITY of the LED's as per the circuit diagram.

Step 3: STEP-3


See the photograph and solder the LED's as per the circuit diagram mentioned in STEP-2.

Step 4: STEP-4


Fix the Stepdown Transformer in a Metal Box.
Fix a Wooden batten to the Cover of the metal Box with a up & down JOINT.
Fix the LED Light Assembly to the JOINT with screws.
Connect the output wires to the light assembly.
Fix a 2Pin male plug to the input wire of the Transformer.
Please see Photograph for guidance.

Step 5: STEP-5


Here I have made another AC light using 10 mm Milky White LED's. (see photo)
A Stepdown AC transformer of 220 volts to 18 volts is used.
18v x 1.4 = 25.2 divided by 3.3 = 7.636 so I have used 6 LED's because of 10mm size LED's.
I have used 6 LED's in series and 4 rows of LED's in parallel.
The same Circuit is used but without a changeover switch.
This light unit is very bright and can be used as TV viewing Light and Emergency light.
Cost of the light unit comes to 2US $ in India.




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    58 Discussions

    I'm new to LED and you seem knowledgable. I was wondering; What is UPC you mention in first paragraph? Is there some way to determine the voltage of an LED if I pulled it from and old computer or toy AND does it matter?

    A NOKIA mobile charger Model No. APC-8E

    Input ----100-240vots.

    Output ----5.3volts at 500 mA

    Yes it is possible with a Mobile charger of this type.....

    Charge what????? This circuit does not have any battery as it runs on 220VAC and 12 volt DC......

    If you want to run it on a mobile charger you will have to change the circuit completely.............

    Hello mate,

    From your 10mm LED AC light, with 18VAC (25.2 Vpk), u have 2 parallel sets of (6led x2) connection correct ? Roughly how many more 6x2 led can be parallel added to it ?

    What if with household 240VAC, a .22uF & 1K ½W resistor, 7led x2, any limitation of parallel connection ?

    By adding one Bridge Rectifier, should be able to filter the flicker effect right ?

    5 replies

    On 240VAC, a .22uF & 1K half Watt resistor,
    you can put up to 30+30 led's on a 500 milli watt 12 volt step down Transformer.
    If you put more then 30+30 the light starts to go dim, but it will glow.

    pl clarify- on 240vAC, 30+30 leds can be used with a .22uF & 1K half Watt resistor. Alternately use Step DnTransformer (230AC-12vAC ) for LEDs. Am I correct? your sentence is not clear..

    NO. For using 220 volts with a .22uF & 1K half Watt resistor, the circuit is different. See my LED TUBE LIGHT Instructable.

    Read lots of your post & QS's, about using LED with AC,

    The max number of LED can direct connect to household is 240 * 1.4 = 336Vpk 336 / 3.3 (led Vf) = 101 minimum number of LED directly connect to VAC.

    1) With lower number of LED, I need a .22uF & 1K ½W Resistor, does this C + R set support, as randomly as 45 + 45 led's ?

    2) With this C + R combo, does it support four legged Superflux LED ?

    Thanks mate : )

    101 minimum number of LED directly connect to 240 VAC.
    Your calculation is correct but it should be 101+101LED's.

    Regarding four legged Superflux LED, I have no idea, never used it.

    in the schematic you used a step up transformer. its supposed to be less windings on the secondary coil.

    1 reply

    It is a step down transformer, sorry to have placed the transformer in the wrong direction.