Lighting Lots of 1.2v Bulbs...or Bright LEDs

Hi All,

I've realised this is actually quite an involved project for an electronics newbie!

Wondering if anyone could offer me some electronics help...not specifically Ardunio.

I've got to the point where all I'm trying to do is light a single bulb using a 9v battery. This is working, although the light is very dim.

Heres what I did:

  • 9v (Battery) minus 1.25v (Bulb) = 7.75v
  • 0.25w (Bulb) = 250ma
  • 7.75v divided by 0.25a = 31ohms
  • I only had a 33ohm resistor, so 7.75/33 = 0.23a (230ma)

So - I attach the +9v of the battery to one terminal on the bulb holder, ground/negative to the other terminal, with a 33ohmn resistor (Orange/Orange/Black/Gold) in-line.

It just about lights up...in fact only seems to light up when I touch the terminals with my fingers...not sure how this is affecting it.

Worth mentioning I was following this:
http://www.wd5gnr.com/basiccir.htm

Anyways...I accept this is not arduino related. Any help much apprecited!!

Thanks!
Simon.