Flashing strip of LEDs

[hanna256]

I have a 12V powered LED circuit. 6LEDs in total, with 50ohms resistors.

Now, I would like to make these LED flash, at a slow rate (1/4 second on, 1/4 second off). I am a bit familiar with the 555 timer circuits, but will the 555 be strong enough to drive those 6LEDs (they are 20mA, 2V leds). What if i increase the LEDs to 24 LEDs in the future (4 strips of 6 LEDs), will the 555 still be enough, or do I need to add a relay or something similar?

Will it be better to go with a micro-controller? I am not familiar with that, but would like to try it just for fun. Where will it be a good place to start with micro-controller circuit driving LEDs (there are tons of sites, I know, but would like to start somewhere good and complete). Micro-controller is probably overkill for this, but this would be a good time for me to learn it.

Thanks

 

[MikeMl]

The 555 is capable of driving ~200mA, sourcing or sinking. There will be a slight (~0.5V) drop between the 555's pin 3 and either 12V or ground, depending on how you have the load connected.

 

[hanna256]

Thanks for the reply.

Now if I want with one pushbutton switch to have 4 functions: 1 press - Turn ON Solid lights; 1 press - Turn blinking leds; 1 press - Increase the blinking (twice as fast); last press - Turn OFF.

Do I need 4 LEDs drivers?

 

[MikeMl]

You need a dual Flip-Flop wired as a 2-bit, four-state, counter. The decoded states of the counter can control the 555's blink rate.

 

[hanna256]

The output of the decode state is either 00, 01, 10 or 11. Right? How do I control the blink rate with that? It has been a long time since I came up with an electronic design, I am bit rusted...

 

[MikeMl]

Actually, those are the counter bit states. A 2-line to 4-line decoder would give you four outputs, which are true one at a time. The four outputs can be used to modify the operation of the 555.

 

[hanna256]

Thanks again.

I had some kind of LED flash light that I just took apart. The flash light had 6LEDs, with a pushbutton and 3 batteries. One pushbutton the LEDs are ON solid, than one pushbutton they blink, and so on (there 6 different settings). I was surprised to see 3 components only: The pushbutton itself, One component that looks a surface mount resistor that just says "M1" on it, I measured is about 260ohms. And one big "resin" bulb (or dome) that I am guessing is some sort of cheap way of making a capacitor. Is that possible? No IC, nothing, just those 3 components, 2cm by 2cm PCB!!! The LED are regular LED (no flashing, 2 pin LEDs, not tri-color or anything).