Hi Guys,

Is it possible to make the red LED flash 2 times then stop, then make blue LED flash 2 times just using a 555 timer? Diagram will be much appreciated

 

Hello,

I have taken your post to its own thread, so it will get more attention.

I think you can use the 555 for the speed and an 4017 sequential counter with some decoding for it.
Take a look at this post from Bill_Marsden:
http://forum.allaboutcircuits.com/showpost.php?p=117647&postcount=12

Greetings,
Bertus

 

Hi bertus,

Great thank you for the link I will look at it now.

Regards,
gadget

 

Hello bertus,

Now I have a question regarding the link you posted, it is shown on the diagrams that I have to use transistor and diodes, but it is not specified what type of transistor or diode I should use. It is not specified does this means that I can choose what type of transistor or diode I want? I would really appreciate it if you could shed me some light

 

Hello,

In the first picture of the post it says:
CR = 1N4454 , 1N 914 or equivalent.
Q = 2N222 or equivalent.

The same components are used in the other schematics.
Perhaps Bill will verify this.

Greetings,
Bertus

 

Great thanks sir, I was thinking the same thing but I just want to be sure than sorry.

 

I had a similar request for a virtually identical circuit, which I did. I'll hunt it down and post the link, but I'm about to step out the door.

It can be done, and is fairly easy. It took 3 555s, one to select which 555 flasher was lighting up, and the other two to flash their respective LEDs.

 

It appears I misremembered, a fourth 555 was used to create an inverter. I drew several versions, this was one of them...

This was the thread...

http://forum.allaboutcircuits.com/showthread.php?t=17499

 

It appears I misremembered, a fourth 555 was used to create an inverter. I drew several versions, this was one of them...

This was the thread...

http://forum.allaboutcircuits.com/showthread.php?t=17499

Thank you sir I will check it right away

 

Something is bugging me, what you just said is what was going in my head, 2 555 timers for the blinking for each set of LED's and the third 555 timer is used to pick which one of the 2 555 timers will run.

Is this possible? Anyhow I will try to make this work, if not I will go for your circuit the 3.1 version police flasher.

Many Thanks and best regards

 

Sure, but you would replace the one 555 with a couple resistors and a transistor to act as a logical inverter.

See U2A? That's just being used as an inverter.

So, instead of using two 556 timers, you would use one 555, one 556, and a transistor with a couple more resistors.

 

And wind up with more parts.

The original article I referred to wound up gravitating to the original suggestion, a 555 and 4017.

You could also use multivibrators and use 7 transistors.

There really is a huge number of ways to do this.

 

Yep, there's lots of ways to do things; the possibilities are endless.

Speaking of keeping parts count down, I just had another look a bit ago at the thread of yours that Bertus linked to... I trimmed 72 parts from one of your schematics replacing them with 3, and it still does the same thing.


Original:

Modification:

 

There is a problem with the idea though, it assumes all the diodes (quantity and colors) are the same. We have enough trouble getting people new to electronics used to the idea that a resistor is required (What if I regulate voltage, or I want to get the parts count down).

The idea was persued somewhat with the current regulator earlier in the article.