LED Pulse/Fade Circuit for 120mA/0.5W LED

[Mr. Oddly Fox]

I need help making a LED pulsing/fading circuit that can handle a 120mA/0.5W LED; such as this:
http://www.ebay.com/itm/161006586115?_trksid=p2060353.m2749.l2649&ssPageName=STRK:MEBIDX:IT
These LEDs are very bright, which suits my use for them in party lights.
However, the circuits I have theorized in NI Mutlisim... fail.

 

[Harald Kapp]

Before we start suggesting the same circuits that failed in your simulations, tell us which circuits you simulated.

Pulsing is easily done with a 555 timer. Power to the LED is driven b y a simple single transistor stage (see our ressource section).

Fading can be don in an analog, power wasting way by creating a triangular control signal instead of a square wave. Or in a power effcient way by using a PWM control signal. The PWM signal itself can be craetaed in many ways, from analog to purely digital. A modern way would be using a microcontroller which can simultaneously be used to e.g. check an input which tell it to turn the LED into different states (on, off, fading) etc.

Which solution would you be comfortable with?

 

[Mr. Oddly Fox]

I think a circuit incorporating a 555 timer would be the best. That is the circuit I was working with. I was getting somewhere with that, the circuit would turn on and get power to the LED for a second before the timer blew. The problem I have come across in multisim, was the timer failing. I was running it from a 5V DC power supply which is what I have in my stock. Though, purchasing another power supply is not out of the question. I just need a set of components that will do the job, while being preferably reliable

 

[Harald Kapp]

A 555 should work fine for up to 18V max. (datsheet). The 5 V operating voltage is not the issue.
How did you drive the LED? Did you limit the current with at least a resistor?The 555 should be able to drive up to 200mA , although I'd recommend a separate transistor stage for decoupling.
Show us the circuit diagram you've been working from so we may be able to spot the problem.

 

[Harald Kapp]

Here's a related thread.

 

[Mr. Oddly Fox]

This is the circuit that I was working with. The only thing I changed was the source voltage, but I mentioned that could altered.
That thread seemed interesting, but I couldn't really tell what kind of LEDs they were powering, the ones that I am using have a forward voltage of around 3.6V. Maybe, running the 555 and these in the circuit is limiting the voltage?
To elaborate more on the timer failure, the pin that was coming off as broken was pin 3; output.

 

[Harald Kapp]

That circuit looks o.k. 9V is o.k., too.

the pin that was coming off as broken was pin 3

Do you mean mechanically broken? I'm sure that's not an electrical issue as it will take much more current than any of the components used can tolerate to melt the pin electrically.