Problem with led flasher

[Cipop]

Hello guys,

I'm new here, and quite new to electronics overall...
I wanted to create a LED Tape flasher for my quadcopter, but because it has to be as small as possible I've decided to buy pre-made smd IC that's only 18x25mm in size.
Here is the circuit:

Circuit is runed under 12V batt

But I'm havein a problem now.... this circuit doesnt completly turns off my LED strip, it just like dims the strip that should be turned off. Any idea why this is happening ?


Best regards.

 

[George]

When you bought the board did it say 12v was OK?

 

[Cipop]

When you bought the board did it say 12v was OK?

Yeah, it said that batt voltage can be from 4.5-12V, it said it deppends on voltage under which lights can work...but this led stripe can work on 12V w/o a prob.
Does it have anything to do with resistors...cuz this led's allready have their resistor on the tape itself...

 

[Daithi]

Are you sure that the circuit can be used for LED's? Reason I ask is that it is possible that there is some residual current built up (left) in the inducers (L1 & L2)... This residual current may keep the LED's on for a while until their energy has completely dissipated...

 

[Fleck]

Aren't L1 & L2 the lamps?

The LED strips use that little current compared to a lamp that the transistor is lighting them a bit. try making R4 & R6 smaller, this will pull the bases down better and switch them off.