Instructables
Picture of LED SunGun

Intro:

A follower of mine on Instructables wanted to build a LED light to be used in Photography and wanted my help,

so I took up the challenge and built this LED SUN GUN  which runs on AC. 

It is cheap in comparison to the ones sold in the market and as it runs on AC there is no battery problems.

 
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Step 1: Parts you will need…..

Picture of Parts you will need…..

Sixty- Extra bright, white 8mm LED’s

One- AC transformer 220volts to 12volts of 2Amps.

Four- 1N4007 Diodes for bridge rectifier.

One- Condenser 470uF anything from 25 to 65 volts will do.

One- ON OFF switch.

Wires, solder, wall plug, tools etc;

Step 2: Old Sungun….

Picture of Old Sungun….

I had an old Sun gun (halogen tube type) in my junk with a fused tube.

I opened up the casing and threw away all the parts inside it.

Next I took a PVC sheet and cut it to the required size to be used as a base for my LED’s.

Step 3: The Circuit…

Picture of The Circuit…

60 number of Extra Bright 8mm White LED’s are used in this Sun Gun.

The LED series/parallel 6 x 10 array uses 60 LED's exactly.

This circuit uses 10 parallel rows of 6 LED’s in series as shown in the Diagram.

Follow the Circuit and make the LED arrays.

The calculation:-

Transformer output without load is 14.4 x 1.4 = 20.16

20.16 / 3.5 = 5.76 or 6 LED’s in a single row.

8mm LED’s 3.5 volts consumes 30mA current.

The transformer puts out 2A = 2000mA.

Each row consumes 30mA, so you can put 2000/30 or 66.6 rows,

but round DOWN to get a maximum of 66 rows.

OR 66 x 6 = Total 396 LED’s.

 

For 3 panels of 10 rows each, the total comes to 30 rows: with each row consuming 0.30 amps (30mA), 30 *

0.3 = 0.9amp, which the SINGLE 1N400x bridge can handle fine. It’s ONLY when you have more than 30

rows that you need worry about the Double Rectifier.

 

mojontali5 months ago

Dipankar

Any way to dim the lights ?

regards

Dipankar (author)  mojontali5 months ago

You can try and put a electronic fan regulator in place of the switch, which has a capability to work up to 5 Amps.

But r they PWM devices ? otherwise normal dimmers cause flicker..have u tried it ?
Dipankar (author)  mojontali5 months ago

I said you can try, I have not tried it.....

The other way is to divide the 10 rows to 5+5 and put a single pole double throw switch (SPDT) .

hmunir5 months ago
this wont work
Dipankar (author)  hmunir5 months ago

For 3 panels of 10 rows each, the total comes to 30
rows: with each row consuming 0.30 amps (30mA), 30 * 0.3 = 0.9amp, which the
SINGLE 1N400x bridge can handle fine. It’s ONLY when you have more than 30 rows
that you need worry about the Double Rectifier.

tbarot Dipankar5 months ago
30mA=0.03A
scci5 months ago

This wont work... the electronics as well as the theory.

Dipankar (author)  scci5 months ago

It is working well...........

For 3 panels of 10 rows each, the total comes to 30
rows: with each row consuming 0.30 amps (30mA), 30 * 0.3 = 0.9amp, which the
SINGLE 1N400x bridge can handle fine. It’s ONLY when you have more than 30 rows
that you need worry about the Double Rectifier.

Dipankar (author)  scci5 months ago

It is working fine......

tbarot5 months ago
Are the positive and negative wires interchanged?
Dipankar (author)  tbarot5 months ago
(removed by author or community request)
tbarot Dipankar5 months ago
check the bridge rectifier
Dipankar (author)  tbarot5 months ago

Checked and corrected.....Thank you....

Dipankar (author)  tbarot5 months ago
(removed by author or community request)
qs Dipankar5 months ago

The diodes in the bridge should be reversed!

tbarot qs5 months ago
At last someone agrees with me! Thnx qs
Dipankar (author)  tbarot5 months ago

Sorry folks, there was some confusion in the Power supply which now has
been rectified.........Thank you all for pointing it out....

Dipankar (author)  tbarot5 months ago

Yes , Sorry for the mistake..........

rajath5 months ago

What changes should I make if I want to connect LEDs in series instead of parallel?

Dipankar (author)  rajath5 months ago

Series and parallel are both required to distribute the load of the Transformer.

rajath Dipankar5 months ago
Great thank you. I think I will be making it the same way you have mentioned Will tell you how it goes. Thank you
Dipankar (author)  rajath5 months ago

Sorry folks, there was some confusion in the Power supply which now has
been rectified.........Thank you all for pointing it out....

Dipankar (author) 5 months ago

Sorry folks, there was some confusion in the Power supply which now has been rectified.........Thank you all for pointing it out....

Krinkov5 months ago

Did you actually try and build this? Your power supply will only generate 17 volts and you would need 21.7 volts for any current to flow through the diodes. If you did build a supply with a high enough voltage, you would need some way of limiting the current flowing through the LEDs. A two amp supply split through ten LED branches will draw 200 milliamps per branch. If your LEDs are rated for only 30 milliamps, you will smoke them all with that much current.

Dipankar (author)  Krinkov5 months ago

See the calculation.....It is working fine.... Try it out and see for yourself....

Hi, thanks for the very informative article, I'm already looking at this circuit. And here's the circuit I'm really excited. So thank you very much.

fred275 months ago
I have to agree with Krinkov. This won't work.
hmuhammad15 months ago
the 8mm strawhat LED is not longlasting LED in my experience..
alcurb5 months ago
Brilliant !!
Q-Asif6 months ago

:D thank you

pandyaketan6 months ago

5***** !