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by technogeek-1995

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I have been working with some LEDs and I was wondering what IC I would use to make a dual strobe (with 2-16 volt LEDs). I was hoping I could get it to Strobe, RED (x2) and AMBER (x2) and so-on...[Blink, Blink (red)...blink, blink (amber]

I have no clue what to use. I have tried several ICs and still no luck.

Sorry if you were looking for a computer question. :)

6 replies

by older mycroft

Don't be surprised that computer geeks [i]might[/i] also be electronics addicts too.

For constant regular flash:
http://www.maplin.co.uk/module.aspx?ModuleNo=35804&doy=31m8

For twice per second flash:
http://www.maplin.co.uk/module.aspx?ModuleNo=2103&doy=31m8

To drive these units, you'd be looking at the
LM358 or, better still, the LM380.

In conjunction with an IC4017.

This link shows a typical circuit diagram:
http://www.elecfree.com/electronic/strobe-light/

I'm not aware of the electronics component suppliers on your side of the Big Pond, but if I can find these in-built IC LEDs in the UK, you must have similar suppliers in the US.

Job done ;)

ps - I have seen these circuits used with bi-colour and tri-colour LEDs but for some reason the multi-colour LEDs are proving difficult to find today.

** Here's another circuit:
http://www.elecfree.com/circuit/circuit-light/nite-rider-lights/

by thechas

There are numerous ways to make LEDs blink.

A basic flasher circuit would use a 555 timer as the clock source and a dual flip-flop or even a binary counter as the flash control. You then need a driver circuit to interface from the logic to the LED.

Of course these days, you can do it all with a PIC or an ASIC.

Still, I recommend that you start simple and understand the building blocks that make up the circuit.

I don't even know if it is still in print, but a book titled The TTL Cookbook by Don Lancaster is a great way to learn basic digital circuits.

Thinking about available logic chips, you might want to look for the CMOS Cookbook.

Keep in mind that most logic chips and CMOS chips in particular cannot drive an LED directly. You either need a high current buffer IC, or a transistor driver.

Chas

by thechas

There are volumes of books on the venerable 555 timer. Not bad for a component that is over 30 years old.

Now, for what you want to do, the 555 just is not designed to operate that way. The 555 will provide a clock signal of the frequency and duty cycle you desire. But, to set up flashing sequences you will need flip-flop and counter circuits.

Here are some links:

http://www.discovercircuits.com/T/timers.htm

http://www.hobbyprojects.com/C/Counters_and_Timer_Circuits.html

Based on your questions, I recommend some basic electronics training. This might be a good place to start.

http://www.ibiblio.org/kuphaldt/socratic/

Chas

by mjd420nova

There are a large number of 7400 series chips you could use to run the sequence you're looking for. Many different gates are available and it depends on your preference and local availablity of these chips. You could even salvage some from older logic cards available from a salvage dealer. This series of chips run on 5 volts which is suitable for most LEDs and come in many logic gate configurations.

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