I am working on some computer case mods. I am wanting to redo the LED feet so they do a breathing effect. I wanted to do this without using ICs so I could try and cut costs to a degree. I found a circuit that produces the desired effect, but I need to modify it. I want to use four LEDs in double-pair parallel (2 parallel LEDs on two parallel feeds from the same timing circuit). Below is a picture of the initial circuit that I found.
What I want: I do not have the ability to modify the circuit as precisely as I need. All the software I have will not allow me to calibrate the simulated NPN components to the specifications needed by the one depicted in the diagram. My concern is the capacitors will discharge too quickly with four LEDs pulling from the same circuit. I'm looking for input on how to modify it. I know boosting capacitor size would increase the pulse duration, but I'm not sure how the NPNs would respond because I cannot simulate them properly. So far what I have is like this:
Electrical specs:
Circuit will be powered with available PC power interfaces: IDE, SATA, Floppy
LEDs are Blue 3V typ, 3.2 max
The first diagram contains most of the noted parts.
EDIT: I have changed the source to 12V.
What I want: I do not have the ability to modify the circuit as precisely as I need. All the software I have will not allow me to calibrate the simulated NPN components to the specifications needed by the one depicted in the diagram. My concern is the capacitors will discharge too quickly with four LEDs pulling from the same circuit. I'm looking for input on how to modify it. I know boosting capacitor size would increase the pulse duration, but I'm not sure how the NPNs would respond because I cannot simulate them properly. So far what I have is like this:
Electrical specs:
Circuit will be powered with available PC power interfaces: IDE, SATA, Floppy
LEDs are Blue 3V typ, 3.2 max
The first diagram contains most of the noted parts.
EDIT: I have changed the source to 12V.