An emergency lamp using SMD LEDs is able to generate illuminations with extreme brightness due to the high efficiency of the SMD type LEDs. Moreover, SMD LEDs also ensure the unit will be very compact and lightweight.
The following post explains a simple circuit diagram of an automatic emergency lamp using 36 nos. SMD LEDs. The circuit has been presented in response to the following request sent by Mr.Ali Adnan.
Circuit Request for SMD Emergency Lamp
I've 36 SMD LEDs(Side View Type), I Extracted them from my Broken Laptop's LED LCD screen. I tested them with multimeter and found all LEDs in working condition.
Now I want to make some useful from them like an emergency LED lite. I'll remove all 36 LEDs from strip and mount them on a PCB (will be Tough JoB Mounting SMD's) once you will design a circuit for me to drive them.
I don't know much about SMD LEDs so that's why I am bothering you. I googled for data sheet for that type of LEDs and I think I found right data sheet for this LED, please also compare the pictures of LEDs and data sheet.
I am attaching actual pictures of LEDs that I have and also attaching data sheet, please check and help me with a simple circuit with simple parts. and just for information I've not found the IC ZXSC310 (that you used in your 1 watt LED circuit) here in Lahore Pakistan 🙁 and I am too sad for this.
Waiting for your Reply.
Best Regards,
Ali Adnan Khan
"Hi Bro,
What kind of emergency light do you want to make? Automatic AC/Dc operated or just direct on battery?
The datasheet and the pics are OK.
Best Regards,
Swagatam"
"Hi, thanks for your reply bro. Automatic AC/DC operated with battery backup."
OK, here's an automatic ac/dc emergency light circuit using the proposed 36 SMD LED lights which is easy to build, cheap and yet reliable.
CAUTION - THE CIRCUIT IS NOT ISOLATED FROM AC MAINS, UTMOST CARE MUST BE OBSERVED WHILE TESTING THIS CIRCUIT IN UNCOVERED POSITION.
ALTERNATIVELY YOU MAY INCORPORATE A 12V, 500MA DC ADAPTER ACROSS THE ZENER DIODE INSTEAD OF THE SHOWN TRANSFORMERLESS POWER SUPPLY FOR AVOIDING THE ABOVE CAUTION.
The Design of a an Automatic SMD based emergency lamp is shown below, as per the above request specification:
Parts List
All resistors are 1/4 watt, 5%,
- R1 = 1M
- R2 = 1K,
- R3---R14 = 56 Ohms
- C1 = 2uF/400V PP Capacitor
- C2 = 100uF/ 25V
- D1, D2 = 1N4007,
- D3, D4 = 1N5402
- T1 = TIP127
- Z1 = 15V 1 watt zener diode
- Battery = 12V/2AH
- LEDs = SMD, 3V white, 20 mA
Hi sir, I would like to know about the emergency light with more brightness. Please send me a simple diagram with capacitors value,
Hi Shahnawaz, you can try the concept which is explained in the above article. It will give you maximum brightness. But you will require a Li-Ion battery for the high brightness and long back ups.
Automatic ac led lamp to operate when ac fail and it will go to dc battery circuit digram
hello sir,
sir i want to use two 6v 1aH BATTERIES in series with the circuit,so what modification would be required.
Hi Siddarth, you can use the same circuit as given, no modifications would be required,
sir the batteries i am using are 6V1aH li-on battery, Will that suffice ??? also the led smd i have with me has 84 units in it so any modification would be required???
Also i want to add a feature of IR control, so what should i do??
Siddharth, 6V 1ah is OK for the circuit, but it won't support 84 LEDs, it would get discharged very quickly.
for IR control you can try the following method
https://www.homemade-circuits.com/2012/02/how-to-make-simple-infra-red-remote.html
sir,
i want to use two 6v 1AH batteries in series. So what modifications would be required.
Hii.i want 220ac to 22volts dc 2.5amps circuite with out transformer.
sir how much time does take for full charge??
70mA 12V
This circuit how many output voltage & amps
I used 12v realy this circuit out voltage & amps please tell me sir
use a 12V relay with 300 ohm or 400 ohm coil resistance
I used ac supply working time LED OFF MODE I used relay what volt realy used sir please tell me sir
relay coil voltage should match the zener voltage….
Iam add in 12v 2 amps Battery Two Battery parller
ok will do.
I want one 12v 4.5amps battery any modifications circuit diagram please tell me sir
no modifications would be required
Thanks you sir
How to converted battery zener series
Or parller connect please tell me sir
connect the black line of the zener with the battery (+) terminal and the other side of the zener with the battery (-) side…use a 14V 1 watt zener
How to Stop over charging this circuit
connect a 14V/1watt zener diode right across the battery terminals, this will do the job for you.
I used 12v 4.5amps this circuit
I used 6v 4.5 amps this circuit diagram
you can use the second circuit from the following article:
https://www.homemade-circuits.com/2014/06/flashing-led-battery-status-indicator.html
use only a single 5mm red LED with the last transistor
How to fixed charging indicate led ?
I used 2 12v 2 amps battery parallel how to modify circuit?
This circuit support 6v 4.5 amps battery used?
Connect a resistor in series with D2, and connect an LED parallel to this resistor, as long as the battery charges this LED will glow and will gradually shut-off as the battery reaches full charge.
the resistor value could be anywhere between 2 and 10 ohm….you will need to experiment the right value
if possible connect a 47 ohm resistor in series with one of the LED lead for safeguarding it