Slow pulsating LEDs - how can this be done?

[Marco Scheloske]

Hi,

I`m playing around with the idea to equip Scale Solutions "Tin Man" from Star Trek: TNG with slow pulsating LEDs, to enhance the "it`s alive!"-effect. Not blinking (that would be easy), more "bionic".

What I want to have is a cluster of 4 or 5 LEDs that fade slowly from 100% brightness to approx. 50 - 60%, then going up back to 100% and so on. The speed of that should be more or less equal to a slow breathing speed.

I`m a novice to electronics, so if someone here as an easy solution to achieve such an effect pelase let me know!

[USSARCADIA]

I think Micromark has a set-up for a scale lighthouse. That could work.

[Sparky]

There's a circuit in the electronics forum in one of the stick's. I have several examples of it wired up...

[SGluedMyFingers]

Fader units here

And there is a green "fader" LED in the drop down menu here. Most of these are blinkers, but they have one green that just fades. I'm not sure how these will wire up with other LEDs

Now if you want to make your own circuit, that's a little out of my league.

Not exactly in your area, but with the exchange rate where it is, that should almost pay your shipping, if they ship internationally. I bet they would.

[onezero]

Zog made something along those same lines as an example for me several years ago ---- he's the Grand High Guru Poobah of crazy circuits -- and if you ask nice, and sacrifice the requiste number of styrene kits to the appropriate modeling deities, he may even draw you a diagram.

[TER-OR]

There's an entire forum devoted to all manner of electromagnetic candy.

[Marco Scheloske]

Fader units here

Perfect!!!

Many thanks for that link!

[SGluedMyFingers]

[Sparky]

if you're upto making your own, here's one with two adjustments, the period and the level to which the LED will swing down to (so it doesn't shut all the way off). If you don't want it to go all the way on just up the LED resistor.

http://www.cpemma.co.uk/throbber.html

[jwrjr]

It's fairly easy for me to program a controller to do that. But if you've found an off-the-shelf product to do what you want, go for it.

[Marco Scheloske]

It's fairly easy for me to program a controller to do that. But if you've found an off-the-shelf product to do what you want, go for it.

Maybe I`ll come back to that if the fader won`t do what I intend. I`ll keep it in mind.

[jwrjr]

I can do this as a completed and tested module (preferred, that way I can test it before it goes out), a parts kit, or a pre-programmed chip with a schematic. Lest I give the wrong impression, I test all chips before I send them out.

[Marco Scheloske]

I can do this as a completed and tested module (preferred, that way I can test it before it goes out), a parts kit, or a pre-programmed chip with a schematic. Lest I give the wrong impression, I test all chips before I send them out.

Here I am again...

The fader unit does NOT what I want it to do.

Ok, it does partially:
There are two yellow and two white LEDs attached to the module (it came completely assembled and tested). When activated the first pair (the white ones) fade up to full brightness, then they fade down to "off". The the two yellow ones make the same run, and so on.

The speed is fine, the brightness is fine.

The only problem is: One of the white LEDs doesn`t go completely off, but stays glowing low. That ruins the desired effect.

I contacted the manufacturer, and all he was able to tell me was: "That`s the way it is, the chip has problems with white LEDs, and it doesn`t like more than 3 attached to it. It was designed to be used for red ones, it works fine with them"

Well, the seller is OFFERING custom colored LEDs, but he says nothing about that problem on his website. "Great" customer service...

Soooo... if you still want to help me we should figure out a trade.

[SGluedMyFingers]

Hmmm. Well I hate to hear that, Marco. I feel that I steered you in the wrong direction.

Admittedly the website does not provide every detail, but they have always been happy to help me with questions. I am sorry that your experience went differently.

But didn't you want the lights to go from 100% down to 50-60%? Regardless, I guess, if it is not uniform.

I am going to call them to ask if "I" myself could substitute different colored LEDs on that unit. I'm sure that would void any warranty, but if they say that that is possible (I believe most of their LEDs are very similar) I may offer to take that off of your hands to ease my conscience and I have a project that that may be useful for - just not those colors. But I already have a handful of their LEDs. Well, they are superbrights. Let me contact them and see what I could do with it.

It is 6:00 am in California right now. I will have to call them from work today and touch back this evening with you.

How bad was the shipping to Germany?

Edit: I just noticed that the description of that unit states that custom color combinations should be "called" in first. I don't remember it saying that previously. I wonder if they changed that due to your problem?

Anyway, I'll get back with you on this, Marco. Unless you would rather just try to work out a deal with jwrjr.

If we all work together, maybe we can find a solution that we will all be happy with.

[Marco Scheloske]

Hmmm. Well I hate to hear that, Marco. I feel that I steered you in the wrong direction.

No need to apologize or to feel bad, my friend!

The fact that the information on their website isn`t complete (at least for someone who has no idea how this electronic stuff works - their first mail when I wrote them my problem was in the way of "what did you expect with a complete module for such a low price" - hey, I don`t know what that stuff costs, so I don`t know if a module is cheap or not!) is not your fault.

Yes, originally I wanted a module that goes to 100%, than to 50 - 60 %, than back to 100.

Such a thing was not available, so i thought the fader unit offered by them would be cool to look at, also. I choose the two different colors because I thought that will add a nice touch to the final model when shown at exhibitions.

It WOULD be look cool if that single white LED would go off completely. Like a pulsating heart, or deep breathes. But with that LED staying on a bit it ruins the effect - it looks like a bulb in the model that fades on and off, nothing more...

Also there is a short pause between the two fade-up cycles, I understand their description a bit different here, too: it goes two LEDs up, immidiately down to "off", pause, the other two LEDs up and so on.

I thought (and hoped) it would be without a pause, so that you can`t tell when the cycle starts and when it ends - in fact I thought that two of the LEDs would fade down while the other two fade up at the same time, so that you see just a light change in brightness while the color changes more.

Another idea of mine to solve the problem is to add four not-so-bright yellow LEDs to the model so that there is always a slight yellow glow, but more even than the glow from the none going off white LED. I guess I should be able to attach a few LEDs to a 9V battery, even if I know close to nothing about electronics...

That way I hope to get a light yellow glow that brightens up in one cycle, goes down to the light glow, than brightes up again, but to white.

The funny thing is: If all four LEDs of the module wouldn`t go off completely it would look exactly like I want it to. But the problem is that it is just one of the white ones.

Well, live and learn.

By the way, the shipping wasn`t that much (approx 4,- US-$, send as airmail letter post).

[SGluedMyFingers]

the first 2 fade up as the other 2 fade down

Yeah, their description does not sound like what you are describing.

Well, I am sorry that you had a bad experience with them.

Your idea of adding a few solid LEDs to even everything out is not a bad idea. Attaching a few LEDs to a 9v is extremely easy. All you need is a resistor and the LEDs, both which could be found at any electronics store. Oh, and a 9v battery wiring harness - all very inexpensive.

To help, here is an array calculator - all you will need to know is the voltage and amperage of the LEDs that you will be using, which should be on the packaging that the LEDs come in. If you can get LEDs with a voltage below 2.25v (I think most yellows may be near or below that), you could put them in a single series with only one resistor. OR if you only used 3 LEDs, they would certainly fit in a single series with one resistor. Otherwise, you may have to run two series in a parallel. Regardless, this is extremely easy to do. The calculator makes it soooooo easy, especially if you click "view output" as "wiring diagram". My only worry is that four static yellow LEDs may wash out the effect. I would consider going with less, particularly if the LEDs on the unit are not very bright. But if you are looking for a subtle breathing effect, that may be what you want.

Did they offer you a refund? I'm really very suprised. I've had SUCH good experiences with these folks. Oh well, it happens.

If you still want me to help work out a solution between the two of us, let me know. It could turn into a big hassel on both our parts, but I wouldn't mind on my end.

ACK! I'm late for work! LOL!

[jwrjr]

I actually prefer doing custom work. Doing the same thing thing again and again is boring. And I base my price on the cost of the parts, unless the programming is really complicated. This is rare. So let me know. BTW, I just sent a pair of 1701E 'warp cores' to Germany.

[Marco Scheloske]

the first 2 fade up as the other 2 fade down

Yeah, their description does not sound like what you are describing.

*snip*

To help, here is an array calculator -

*snip*

Did they offer you a refund?

1.) I`m happy that I´m not the only one who understands their description different to what the module does.

2.) Thanks for the array calculator - I`ll go the even more easy way: Going to a local electronics dealer, tell them that I want to wire up 3 or 4 LEDs to a 9V battery. I`ll ask them to give me the correct resistors, and everything should go fine.

Wiring them parallel allows me to test out how many "base glow" LEDs I`ll have to use.

3.) A refund? No. As mentioned before, it was more in the tone of "what did you expect for that price?". In fact they told me I should buy two of the other, 2-LED-fader units if I want to get what I want to have for my model. I won`t do so, and because of the good Euro to Dollar relation I don`t loose that much money on the unit I purchased.

Once again, no need for you to take action or to feel bad. This was far beyond your control.

[Marco Scheloske]

I actually prefer doing custom work. Doing the same thing thing again and again is boring. And I base my price on the cost of the parts, unless the programming is really complicated. This is rare. So let me know. BTW, I just sent a pair of 1701E 'warp cores' to Germany.

I`ll try if my "just add a few LEDs to get an even base-glow" will work - if not I`ld be more than happy when I can get the circuit I need from you.

"Small and quick weekend projects" can become soooooo much more work... but otherwise that keeps our hobby interesting.

[SGluedMyFingers]

"Small and quick weekend projects" can become soooooo much more work... but otherwise that keeps our hobby interesting.

I live for this s#*t.

Hope you can post a vid clip when it's done.

[Marco Scheloske]

"Small and quick weekend projects" can become soooooo much more work... but otherwise that keeps our hobby interesting.

I live for this s#*t.

Hope you can post a vid clip when it's done.

Yes, I`ll do so for sure.

[en'til Zog]

Hi, Marco!

I'd suggest using 3 LEDs in SERIES from the 9 volt battery. That way you use up less amperage and the batterie(s) will last quite a bit longer.

3 LEDs in PARALEL - 60 milliAmps total drain.

3 LEDs in SERIES - 20 milliAmps total drain. Three times the battery life.

Model ON!