retrying question dont know if 1st worked.removing cigarette adaptor to use 9v or AA

[joe468]

I have an LED lighting source for my car that works off of 12v .. it has cigarette adaptor at end .. no switches, no fuses. I want to cut the cigarette adaptor off and power the LED's with 9v or AA or AAA ... if this is even possible but I am not sure how.And I dont know the specs on the LED's
thanks

 

[MikeMl]

Likely, there are multiple LEDs in series with a current-limiting resistor. Probably will not work if you reduce the input voltage from 12 to 9V. Here at home, I could answer your question by connecting it to a variable voltage power supply, and watching what happens as I turn down the voltage...

 

[joe468]

**broken link removed**

I dont know if this helps but here is a link to the pic of the packaging. its 3 LED's when I opened the cigarette adaptor there was one lead going to the metal that touches the sides of the car lighter walls.The other lead is soldered to the connection that goes to the tip that touches the back of the lighter receptacle.

 

[MikeMl]

Can you tell if the three leds are wired in series or in parallel?

 

[Hero999]

The lead that does to the tip is the positive and the other is 0V.

My guess is that the LEDs are probably wired in series and will be dim when run from 9V. If this is the case it should still be easy to reconnect them in parallel and power them from four AA cells in series.

 

[joe468]

I tried to attach a pic but couldnt.I will try to describe exactly what I see.This all runs on a small circuit board.The1STs LIGHTS negative attaches to the circuit board.for "this step"of description just goes to the board.1st LIGHTS positive goes to circuit board then RUNS to negative of the 2nd LIGHT.2nd LIGHTS positive attaches to circuit board then RUNS to positive of the CIGARETTE ADAPTOR.CIGARETTE ADAPTORS negative attaches to circuit board runs to 3rd LIGHTS negative.3rd LIGHTS positive RUNS around to a square point on circuit board then RUNS to a soldered point then to another square point then it runs back to negative of the 1st LIGHT. I am hoping to keep the circuit board in line if possible.. damn wish I could attach the picture i took

 

[Hero999]

Sorry, that doesn't make much sense.

Have you looked inside the lamp itself or is that just the plug?

There should be a series resistor or current limiter inside the lamp.

 

[joe468]

I kinda thought that description was going to be confusing LOL .Is there a way to put a .jpg image "from my computer on here so people seeing post can see what i am.. Also I was looking at a site and it seems to be in a series because the positive are NOT connected to positive and the negative Not to negative.

 

[joe468]

on the connection to the led itself i pulled the black housing back and the cable running into it goes right through and connects directly to the LED... so it seems.Could the squares on the circuit board be what you are refereing to?

 

[joe468]

or maybe the connectoin at the bottem in the middle being the resistor to me looks like a solder lol .. sorry hope the pic helps also the first connector ... the right lead is the positive NOT negative

 

[Hero999]

They're wired in series as I suspected.

The resistor is the tiny surface mount component on the PCB.

You'll need to remove the PCB and connect each LED in series with its own resistor, 120R to 150R will do) to run them off four AA cells.

 

[joe468]

Thank you I will give that a try.