So I'm asking for help - not a competition or giveaway or a game or symbiotic like that. Just an appeal to you clever folks out there who might know something I (clearly) don't.
Here's the circuit diagram:
There are two light bulbs (red and green) and a gate that acts like a one-way switch.
Action 1: When the gate is open, only the green bulb lights up
Action 2: When the gate is closed, only the red bulb lights up. Or at least that's what I want.
Assumption 1: Both bulbs are identical so same resistance.
Assumption 2: The gate switch S has negligible resistance.
Outcome: Action 1 (the "green bulb lighting up") works fine, but Action 2 is a no-go.
In theory, what's happening now with Action 2 is that when the gate-switch is closed, both bulbs light up, but dimmer. Bad.
Today I got out my little box of circuit components and tried Action 2 out. Blast! Neither bulb lit up!
Conclusions: Assumption 2 is false (very likely). Or else the batteries are weak (very likely, but I couldn't be bothered to find either new batteries or my multimeter (husband took it) to test them out.
Here are my questions:
- Is Action 2 even possible with 2 AA batteries (1.5 V each) and 2.2V bulbs and a garden-variety switch?
- I heavily suspect that, all other resistances being very small, I need a biggish resistor at point X. Is this true? I was trying to avoid this because I don't own any resistors, color-banded or otherwise.
- Assuming I need a resistor, does anyone know how to make a resistor out of household stuff, like (but not limited to) lemons, foil, candy, old bits of banana peel, dryer lint, diapers, toilet paper, nutella?
On a brighter note, today was not a totally wasted afternoon - the girls discovered me tinkering with my circuit stuff and insisted on joining in. Apparently mum's toys were funner than theirs. So we spent several hours playing with LEDs, magnets and alligator clips and ducking into dark bathrooms to ooh and aah at optic fibers lighting up. Even with having to stop Kate grabbing wires and things, we had fun.
P.S. Sorry, sewing fans. This is not a sewing post. Sewing drives me nuts sometimes. So I dabble in electronics. You?