Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronic Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

Super basic LED Strip Questions!

Status
Not open for further replies.

.sailtoth3moon

Newbie level 2
Joined
May 24, 2011
Messages
2
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,305
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

Advanced Member level 3
Joined
Oct 6, 2010
Messages
709
Helped
196
Reputation
392
Reaction score
194
Trophy points
1,323
Location
Earth
Activity points
5,092
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

Newbie level 2
Joined
May 24, 2011
Messages
2
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,305
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

Advanced Member level 4
Joined
May 17, 2011
Messages
1,461
Helped
374
Reputation
756
Reaction score
370
Trophy points
1,363
Location
Syria
Activity points
12,314
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

Administrator
Joined
Mar 16, 2008
Messages
11,895
Helped
2,021
Reputation
4,158
Reaction score
2,031
Trophy points
1,393
Location
Greece
Activity points
64,377
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

Advanced Member level 4
Joined
May 17, 2011
Messages
1,461
Helped
374
Reputation
756
Reaction score
370
Trophy points
1,363
Location
Syria
Activity points
12,314
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:
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top