So if you had, say, 6 (or 4 or 10) strings of LEDs all "throbbing" independently at, say, 0.5Hz, that would satisfy the effects you need? By throbbing I mean a smooth fade from bright to dim to bright again over the course of a second or two.

 

A mother idea on the pulsing but I don't know how possible it is
I will try to explain

Assuming 66 LEDs
I would like 2 rows to pulse at a time
1st 22 pulse once
2nd 22 pulse once
3rd 22 pulse once
Is this possible using any easy methods)

Or as the 1st 22 is getting brighter
The 2nd 22 is fading

And as the 2nd 22 is getting brighter the 3rd 22 is fading
So that at any one time only 44 of the LEDs are at full brightness

This is all based on the assumption the using a 555 chip or any other method would make the LEDs go from off gradually to full brightness and then fade back out
And NOT on to off to on in a sort of traditional on off instant fashion



But if it is an on off fashion then the grouping would have to be smaller so that pulse appears more random and varied

 

So if you had, say, 6 (or 4 or 10) strings of LEDs all "throbbing" independently at, say, 0.5Hz, that would satisfy the effects you need? By throbbing I mean a smooth fade from bright to dim to bright again over the course of a second or two.

Yes I think having each string of LEDs "throbbing" as you describe would be what we (my people over here with me) was looking for
Would the length of the cycle from start to finish be variable by changing the size of caps or resistors as then we could fine tune to get the best results

 

Yes, I think you can have any throb profile you want. The challenge will be to choose which circuit to use. Look here, here and here, for instance. Or just search this forum for "throb".

 

I found this diagram that I am going to give a try and see if I can split the entire led circuit into 3 sections /thirds and have one constantly on and the other 2 alternately pulsing, and see if that pleases me

 

Thinking outside this thread, have you considered using a remote control device, to have an off-camera technician trigger the electronics on/off, etc... when necessary?

That simplifies the problem from having the prop be practical in terms of controlling the LEDs, to having the effect cued? The practical electronics to drive the LEDs can still be embedded within the sphere, but controlled wirelessly off-camera.

 

Thinking outside this thread, have you considered using a remote control device, to have an off-camera technician trigger the electronics on/off, etc... when necessary?

That simplifies the problem from having the prop be practical in terms of controlling the LEDs, to having the effect cued? The practical electronics to drive the LEDs can still be embedded within the sphere, but controlled wirelessly off-camera.

I've just woken up and I don't understand what you are proposing

Although I have managed to reduce it down to only 4 AA batteries so I have gained a lot if space inside

Edit
I think adding in a crystal receiver similar to that found in an rc car would take up a lot more space then making it all internal
Unless I am thinking about it the wrong way

 

OK I made the schematics on page 3 of this thread to test it out
And it worked like this..
Would adding a cap to each LED make the LEDs breath/ pulse /gradual fade instead of just straight on/off
As I know if I increase the value of r1 and r2 that it increases the length of the wave /cycle
But I am a little puzzled as to how I make it soft fade
But I did find a slightly different schematic that I have seen fading and the only difference I see is he has a cap on each led which to me makes sense
Well I will try that tomorrow and see
But for now I made this
[Yt]DwTkBr-5qcg[/yt]
Edit
Wow spoilers don't work and now yt don't work
https://www.youtube.com/watch?v=DwTkBr-5qcg&feature=youtube_gdata_player

 

To test throbbing with your test ckt. try adding a 1500 to 2000 μF cap in parallel with LED. To be practical a separate LED driver should be used.
A clock[ 555] & a counter [ 4022, 4017 ] makes an event programmer.
'Still think djsfantasi's RF approach is workable & small, see post by cabsbri.

 

OK what's an led driver?
A.and what's the purpose of a counter?

 

An LED cannot control the current through it, it effectively acts as a short circuit. That is why you must use a current limiting resistor if powering LED's from a voltage source, if you don't too much current will flow through the device and it will burn up.

An led driver is a current source, it only allows the correct amount of to pass.

A counter is exactly that, it counts pulses (signals) from the clock (555 timer). By doing this you can make something happen (turn on an LED) when the correct number of pulses have been counted.

HTH Steve

 

ok my head is starting to hurt with trying to get my head around all the variations in 555 pwm circuits
and no looking at 4022 and im completely lost
i have tried to wire 2 555 pulse tierm circuits and only one worked
but it makes the leds flash and well not breathe or pulse
i have found that if i add a 470uf cap in paralel with each led then it gives the effect i want
but i am thinking maybe i can do it with different components instead of using what are actually quiet large componenets
can it be done with transistors instead?

 

Here is an outline to throw rocks at.
The effect is 3 groups of LED's throbbing with about 1/3 sec offset between each group. A fast clock controls the PWM time base & 3 counters supply the slow clock. The 4 th stages are integrated to give a triangle wave form as input to comparator + in.
Another variation is to drop the AND gates & inverters & supply each counter with its own clock, like counter C, the frequencies close but not exactly the same. This would also save 2 ICs All caps μF. The inverters are schmitt triggers. Error: all counters are 4520's , 2 per IC. Suggest 4 AA Ni-MH batteries for relative flat discharge V.

 

On my second suggestion of dropping & gates, add counters to drop list. Hooked up one channel on breadboard to demonstrate throbbing. Added R3 & R4 so that LED did not go completley dark. A 3 sec throb seemed most pleasing. There are enough spare parts for another 2 channels.
R1 started out as a 1 M pot to play with timing & was replaced with fixed value.