Controlling LED Board

[dougk7]

I have an LED Board that I want to be able to control the brightness of with an arduino uno. I'm somewhat of an electronic newbie so any help would be appreciated. (The board used to be connected to a PIR motion sensor)

Picture of board:

[Paul__B]

I see no LEDs!

[PaulRB]

What is fed into those "IN +/-" terminals? 110 or 230VAC? If so, I would guess the large component is a triac, and the output to the panel is also 110 or 230VAC. This will make controlling the brightness much more difficult than with a DC panel.

[Paul__B]

What is fed into those "IN +/-" terminals? 110 or 230VAC?

Better not be, particularly when they are marked "+" and "-" and there is no isolation from the logic supply.  

Not to mention the electrolytic capacitor.


OK, the regulator is clearly a 78L05, but we want to know what the switching transistor is?