LED driver for 16 led's

[mcs51mc]

I have two small black boxes 32*32*20mm with following text on it

Led driver for 16 led's
Input 230-240V/50Hz
Stable output 300mA (CC)
-20°C/80°C

I like the "Stable output" part since both drivers are dead
No more light from the led's

What do I have to put into the small BB to make the leds lit again


I did some tests on the working LED block:
Powered from a DC supply I need 3.2Vdc @ 0.3A cc to lit the led's.

Now my question is: How do I make a constant current source of 300mA / 3.2Vdc starting from 230V/50Hz without any transformer?

Thanks for any input ... ...

 

[ericgibbs]

hi,

Download the datasheet for the LM317, its got a CC application circuit to suit your requirement.


EDIT:
Powered from a DC supply I need 3.2Vdc @ 0.3A cc to lit the led's.

 

[dch222]

No really safe or efficient way without a transformer, except an ac-dc switching supply - expensive.

 

[mcs51mc]

Hi,

Thanks for the replies but:
Concerning the LM317; maximum input voltage 40V so direct connect to mains is impossible

Those little black boxes (35*32*20mm error in first post ) comes from a lamps showed in attached file. I can assure you there's no transformer in it. So how do they do it with no heat dissipation?

 

[on1aag]

Little black boxes.

Hi mcs51mc,

You are not going to believe this but about two years ago, I bought
an entire box with prototypes from Massive at a local fleamarket for
50 cents each. The 16 leds were on a double sided pcb's with a little
black box attached to it. The pcb's had all different shapes and the
leds were in all sorts of different arrangements. I had at least 50 of
them and I sold them all at the next radio rally for 2 euro's each.
I can't remember if the leds were connected series or in parallel.
I was wondering if the leds are individually accessable ?

on1aag.

 

[justDIY]

google for "offline switcher"

also have a look at www.supertex.com, part HV9910

 

[mcs51mc]

@on1aag
Indeed PCB with 16 led's in parallel ?!?
Constant currenty supply with led's in parallel; isn't that a bad design?
How do you control the current through each led?

Did you open a driver or not? Any idea what components are involved?

I think Massive put some prototypes in production



@justDIY
Thanks for the Supertex device.
Datasheet and application note's have always led's in serie, original PCB from Massive is parallel. Did you ever use a HV9910 with led's in parallel?
I can off course make a new PCB

 

[on1aag]

Massive prototypes.

Hi mcs51mc,

I have no idea what's inside the black boxes, mine all worked and
I didn't pay much attention to it at the time. And as I already
mentioned in my previous post, I've sold them all.
But if you have some defective ones, you could use extreme
violence to get one of these mysteries open.

on1aag.