Powering LED strip

[SparkyCal]

Hi folks. Thank-you for the observations. I did get the LED strip to blink, but it had to be at a higher voltage.

If you are saying that the transistor is not a good choice for this, and I should try a CMOS 4093 as an oscillator, I will. At this point, I am making progress in the sense that it is helping me understand circuits. But I take your point that I should use the right components for the job.

Audioguru- than-you for the link to the pin mappimng. I did look it up, but will double check.

 

[duke37]

I have a Heathkit transceiver which uses a reversed transistor as a zener diode so it can work but over driving the base such as in a two transistor bistable oscillator can cause long term changes.
A 4093 can operate from 3V up to 15V and give sufficient output power to drive a medium power transistor or high power darlington transistor.

 

[Harald Kapp]

two transistor bistable oscillator

you mean astable multivibrator?

Imho the simplest and most reliable circuit (in terms of number of components and connections) even today still uses a 555 timer IC.
This IC can drive up to 200 mA, if that is insufficient, use a driver transistor for more current, see our resource.
Imho the 555 is easier to use than a 4093, but the difference is a small one and may be just my personal gut feeling.

Contrary to what @bertus stated in post #4 your LED strip is imho a rather simple contraption. The "intelligence" is in the controller, but the controller is not required to operate the LED strip. Within the strip there are segements (usually marked where you can cut them open) with a few RGB LEDs and series resistors. The strip has 4 connections: R, G, B and 12 V (not so commonly: R, G, B and ground, also called common or 0V). Brightness is varied by modulating the on/off ratio (called duty cycle) of the power to the LEDs.
Note that there are variants of LED strips with built-in controllers (The name WS2812 or WS2813 typically appears in connection with that type of LED strip). These in fact require programming by a controller to produce the effect you want to achieve. Should you be in the possession of such a kind of LED strip, I recommend you one of the simple type and forget (for the time being) about the programmable strip. Judging from your questions I think that is a project for the future when you have collected more experience in electronics, should you desire to do so.

Assuming you have the + 12 V common variant (imho the more common one): any color is activated by applying ground (0V) to either R, G, B or any combination thereof. You can do this by using a bipolar transistor or MOSFET (see the resource I linked above on how to do this) or the output of a 555 timer IC directly (as long as the total output current of the IC does not exceed 200 mA). You may even be able to re-use the respective transistors from within the controller.
Or simply use the controller delivered with the LED strips and set it to blink mode.
Should you have the common ground (0V) variant, you will have to control the + 12 V as a switched power signal to te R,G and B inputs of the LED strip. This requires a slightly different setup using PNP transistors or P-MOSFETs. Should this be the case let us know so we can draw the required circuit for you.

 

[SparkyCal]

Harald: I can confirm what you said about the LED strip. Its magic happens with the controller. But on its own, it simply has a positive terminal and three other terminals. If I connect the positive and alternate between having the negative on one of the three others, the color changes. Other than that, it is just a LED in series (I believe).

As much as I appreciate and respect all the advice I am getting, please remember that I am a newbie. So, I thought I would try to find a simple project to promote my learning (ie: try to make a flashing LED for my guitar, powered by a 9 volt battery). You folks definitely know what you are doing, but bear in mind, it is like handing the keys to a Ferrari to someone who is taking his first driving lesson ;-).
Having said that, I am going to re-read what everyone posted from the very start of this thread. As I continue to experiment, make mistakes and then read the advice, i learn a little more. Sometimes you have to go back and read everything because you're learning has improved along the way, and things previously said may make more sense now.

All that to say THANK YOU and please bear with me. I promise that if I ever get this blinking lED on my guitar., I will, post a video of my playing it ;-). Any requests for songs?

Rigjht now, I am trying to determine wha is the most simple and elegant solution for a newbie. Bearing in mind, the electronics have to be tiny enough for me to put on a guitar. That is why i am choosing the 12 v battery. They are roughly the width of a guitar pickup.

My problem right now, is that there have been numerous suggestions. Not sure which would be simple enough for me to accomplish. I am willing to buy the parts that i need, but I have to first determine the best way to proceed.

 

[SparkyCal]

Just to provide a better sense for this project, here is a picture of the guitar I am working with and the Led strip sitting roughly where it will go.

I am thinking that maybe run black or white wires (whatever blends in better with the color of the guitar and its pickups), down the side of the pickup and maybe have the 12 volt battery rest on the saddle (piece where the strings end). But those are last minute considerations. First i got to get the thing to blink ;-). I will also put an in line switch so it can be turned off when I am not playing.

 

[Martaine2005]

SparkyCal,
Why not buy a unit for £0.99?.
It has ten outputs already for LEDs. If you really want to use you LED strip, you can simply solder your RGB leads to the outputs via a transistor if required.
Or just use the board as it is with 10 red LEDs that flash and the flash rate can be adjusted for fast or slow or in between.
Put some heat shrink over it matching your guitar colour and poke LEDs through purpose cut holes.

Martin

 

[SparkyCal]

Hi Martin. That's an idea and certainly affordable. i was able to find the same unit in my home country on Amazon. My only concern would be the board., It would be a little more difficult to conceal the board, and I am not sure if it would survive, using the guitar for gigging and on stage. That's why I was trying to find small components like a transitor/capacitor.resistor combo to drive this whole thing. others mentioned oscillators and chips. I am open to any of these, but I need to determine which would serve the purpose and be easy to conceal/small.

 

[Audioguru]

The tiny A23 12V battery used in a remote control does not produce the high current needed for lighting your 3 LEDs. They will blink for 2 hours slowly dimming. That is a fairly expensive battery to keep replacing.

 

[duke37]

you mean astable multivibrator?
Yes, my brain is not as agile as it used to be. It took me several minutes to recall "darlington".

I went to a radio rally years ago to get a 4093 to make a power invertor. I asked how much they were and handed over my money and I was handed a tube with about a dozen in it so I have a preferance for this chip. I am sure I have some 555s somewhere.
You only need a resistor and capacitor connected to one gate out of the four. The three spare gates can be used to boost the output or provide three more independant oscillators.
The 555 has the advantage of a much more powerful output but it is no simpler than the 4093.

 

[Martaine2005]

Ok, the board is the size of a 9 volt battery.
Where do you plan to run the wires?. I would imagine over and round the back?.
So the same would apply to what ever you choose to use.
You could get a small piece of coloured perspex and drill 5mm holes for the LEDs?.
Which ever way you decide, you’ll have a battery, wires and LEDs connected to the guitar!.
Hell, go the hole hog and buy a new pickguard for gigging. Drill for the holes for LEDs next to your pickups (btw) are they double taps?.

Martin

 

[SparkyCal]

Thanks for the ideas. No, they are not double taps. I am using the cheapest guitar I have (and I have 16 of them).