Dollhouse led lighting issues:
I have 9 LEDs running off a 9v battery.
They are in 4 parallel circuits.
First is 3x3v
Second is also 3x3v
Third is 2x3v flicker with 100 ohm resistor
Forth is 1x2v slow RGB colour change with 350 ohm resistor.
Can anyone tell me why all the lights flicker except the colour change one?
In isolation each series works correctly but when they are all connected in parallel they flicker. Am I asking too much of a wee 12v battery? Should I attach my colour change in series with the 2 flickers and eliminate the resistors and the forth circuit?
They flicker in a pattern and I think it may be the opposite of the actual flicker LEDs. Could I just remove or reduce the resistor in that series?
Any advice would be wonderful. I’m not too concerned about reducing led life or maximum brightness. It’s not an heirloom or for public display. I just wanted to create a little effect for a few pictures and am curious where I went wrong.
Thank you
Does anything change if you remove the flicker LEDs from the setup?
Yes. It works perfectly.
I have decided on a work around. I will attach the 2 flickers in parallel to a seperate 3v battery.
I also remembered that 1 led in the first and second series were actually a string of 6-8 fairy lights. Not sure if that would affect the (draw? Load? Current?) of the circuit? I feel like it shouldn’t because you can run a string of like 20 of these off a 3v coin battery but surely it must use something…
I tried bypassing the 100 ohm resistor in the flicker series but it made no difference.
Whilst I have a fix for this situation, I am still interested in why this problem occurred so I can hopefully avoid it in future. Perhaps someone knows of a site or app I can use to test a circuit before hard wiring it?
Another possible issue could be that I harvested to 2 flicker LEDs from tealights so don’t have the exact specifications on them. I just know they run on a 3v coin battery so I’m just working off that assumption.
Sorry for such a long winded question. I have little to no real knowledge in this area (obviously) I am just confused as to how the flickers on one leg (for lack of a better word) can affect all the other ones when voltage should stay the same…. It has to be amps right? If when the flickers are not lit, the rest of them are?
It is possible that, even though the total load is not excessive, the flicker lights impose a sudden additional load on the battery that it can’t immediately supply, causing a momentary voltage drop that makes the other lights flicker. You mention both 12v and 9V supply, but if you are using a 9V alkaline battery then it is likely that the high internal resistance cannot meet a spike in demand.
Sorry, I meant 9volt. It is a battery I’m using so that sounds plausible. I was thinking that if the requirement was too high the circuit would just fail but I guess the flickering IS intermittent failure. Thank you for all your help 
I removed the flicker LEDs from the 9 volt circuit. Now it lights for about 10 seconds when I first switch it on then it fades out. The colour changing led continues to work however. 
Hi Nicole
I think you are asking a bit much of that little 9V battery. LEDs are sometimes current hungry and this adds up rapidly.
Could you post a circuit diagram of exactly what you have.
Cheers Bob
Hi Nicole,
To add to Bob and Jeff’s statements, a 6-AA holder is a good choice for a higher-current 9V supply:
The series resistance will be much lower, so the output voltage will be less affected by the current draw of the LEDs. Searching for datasheets of common batteries is a good way to find this out:
