I agree that LEDs would be a much better choice here. Easy to use different colors, too. The biggest downsides are that you need to find the ones to order (tedious e-bay search) and then you need current-limiting resistors, probably about 270Ω for this project.

As for the fan, see how it runs on 6V. Is the idea to ventilate the enclosure? I don't think that's necessary. Certainly not with LEDs.

 

I looked into LEDs and couldn't find any that either weren't expensive or that didn't require any soldering. But I may have been looking in the wrong place. Any good links would be appreciated.

As for the fan, it's not for ventilation. I'd like to have it blow air through a hole that has some strings or something that would then wave around. Kinda like the air dancers at car lots (or Dee from It's Always Sunny!).

I'll try it with 6V...it might be enough to get some decent movement.

 

Ahh, you want to avoid soldering? That does restrict the options. But LEDs are super cheap compared to light bulbs. I bought mine for <5¢ each including the current-limiting resistor.

 

I looked into LEDs and couldn't find any that either weren't expensive or that didn't require any soldering. But I may have been looking in the wrong place. Any good links would be appreciated.

As for the fan, it's not for ventilation. I'd like to have it blow air through a hole that has some strings or something that would then wave around. Kinda like the air dancers at car lots (or Dee from It's Always Sunny!).

I'll try it with 6V...it might be enough to get some decent movement.

Reading another thread, there OP also started to mix two devices that use different voltages. You can take the idea from there. If you add a few more batteries in series, you will have 12 volts for fan. This battery bank can be split half way to give you 6 volts for the lamps.

So the lamps are connected across four 1.5 volt batteries, 4*1.5=6 volts, so the laps receive 6 volts.

The fan (motor_virtual) is connected across eight 1.5 volt batteries, 8*1.5=12 volts, so the fan receives 12 volts.

 

shteii01: I like that idea. Seems a pretty good way to get both the voltages I need.

 

How is your project coming along? Any updates?

I know you're likely beyond this point and that you didn't think the timer idea was appropriate for your goals. I was originally thinking of an internal electronic timer, but your requirement of demonstrating cause-effect kept my mind churning.

I thought of a mechanical timer, whose dial would provide feedback as to elapsed time. And when the dial was almost pointing straight up, it was time to turn it or the lights would go out. A mechanical bathroom fan timer could be used.

Just thought I'd throw it out there. No worries.