Super basic LED Strip Questions!

[.sailtoth3moon]

Hi everyone. This is an incredibly basic project I am doing since I have no experience with electronics, so please bare with me being a n00b.

I have a Randall rh 100 guitar amp head that I want to add a couple LED strips too.

I bought 2 led strips from walmart that are 12volt (meant to be wired to a car). Each package came with a 12 volt battery holder and battery that was rigged to a momentary switch to test the product in store through its packaging. I bought a toggle switch and would like to wire the two strips together (since they have a spot on the back to link them in a series) and run them through a toggle switch to the battery/ies.

Now my question is, how would I wire this? I had a single LED strip lit up through the battery holder that came with the package and the toggle switch worked. but when I plugged second strip in, it seemed to not work most of the time and the battery got really hot. I need to know whether the two 12 volt strips need to be powered by 2 12volt batteries or just one. Also, how should I wire this thing? Is there a way someone could create a diagram for me! And since the thing is meant to be hardwired to a car out of the package that the thing will not need any resistors? from the A23 batteries they lit up so I'm assuming the leds are already resisted.

I appreciate this, and would like to learn more.

So just to recap the materials I have are 2 led strips, 2 battery holders, 2 A23 batteries, a toggle switch, and a ton of wire and tools.

-Ryan

 

[KJ6EAD]

I saw 2 LED strips available from Wal*Mart. Which do you have? Can you upload some pictures of the connectors and everything else? You're probably going to want to power the strips from a plug in power supply instead of batteries.

 

[.sailtoth3moon]

Sorry for the late response. I drew up a diagram. The thing lights up perfect and the switch works. Just I noticed the batteries got a little warm one time I did it. Would like to make sure this looks legit.




Thanks!

 

[KerimF]

I think your LEDs are red because if driven with their nominal current, their forward voltage will be around 2V.
But LEDs should never be supplied by a voltage source because their current (unlike using resistors) will be undetermined. And a small change in the voltage can increase or decrease their current to a great extend (they act much like zeners if you heard of). So since you have 12V and red LEDs, it is better to be content with 5 LEDs in series and replace the 6th one by a resistor. The role of this resistor (R) is to limit the curent. Let us suppuse your LED nominal current is 20mA, R = (12V - 10V)/20mA = 100 Ohms. Since you have two strips... you need two 100R resistors; one for each. Good luck.

Kerim

 

[alexan_e]

I think your LEDs are red because if driven with their nominal current, their forward voltage will be around 2V.
But LEDs should never be supplied by a voltage source because their current (unlike using resistors) will be undetermined. And a small change in the voltage can increase or decrease their current to a great extend (they act much like zeners if you heard of). So since you have 12V and red LEDs, it is better to be content with 5 LEDs in series and replace the 6th one by a resistor. The role of this resistor (R) is to limit the curent. Let us suppuse your LED nominal current is 20mA, R = (12V - 10V)/20mA = 100 Ohms. Since you have two strips... you need two 100R resistors; one for each. Good luck.

Kerim

In which LED are you referring?
The OP said that he has 12v led stripes not single leds , the stripes have the resistors already attached in the leds.

I bought 2 led strips from walmart that are 12volt (meant to be wired to a car).

Alex

 

[KerimF]

Sorry, you are right Alex... when he said that the battery gets hot I thought he is assembling the LEDs.
So perhaps the strips are made with power LEDs because 20mA is .... cool :smile: