Convert battery operated devices to AC power

Submitted by Chuck on

Hi need help. I have very little knowledge about electronics. I am planning for a very small project of converting battery operated devices to AC power. I just recently purchsed a small led light for my display case which is has 3 AAA batteries and want to convert these to AC power.

3 led light with 3 AAA batteries each.

I know I can use a power adapter that has that voltage and mAh but I don't know whether I can use only 1 power adapter and connect all 3 led lights or should I use 3 separate power adapters on each led light. Hopefully someone can help as it is so annoying to keep recharging the batteries every after use.

Sourav Gupta

  Joined February 12, 2018      696

Monday at 02:11 PM

You can use one adapter for three led lights. To do so, calculate the total power requirements when connecting three LEDs in parallel.

C

Chuck

In reply to by Sourav Gupta

  Joined September 24, 2020      1

Thursday at 03:12 PM

I really appreciate the quick response. Thanks for this now I have a peace of mind to do this without frying the device..hehe by the way the AAA batteries that I use is rated at 1.2v with 1100 mAh. So I'll be using total of 9 batteries 3 of each device. So total to 10.8v. Is it okay to use a 12v adapter on this?

Sourav Gupta

  Joined February 12, 2018      696

Monday at 02:11 PM

For single LED, those three AAA batteries are connected in series or in parallel. 

I think it is in series. Thus voltage for single LED = 3 x 1.2V = 3.6V with 1100 mAH (1100 mAH is required for battery only.)

Now, connecting three LEDs in parallel doesnot increse the voltage rather the mAH in 3 x 3 x 3 batteries, which is 3300mAH.

You need 3.6V adapter. What is the forward current of the LEDs?

 

Olivia Williams

  Joined February 27, 2020      55

Thursday at 11:08 AM

Drill a pilot hole in both sides of the dummy battery then screw in some metal screws on both sides. Snip off the connector end of your six volt AC adapter then strip the two wires.