Weird Flicker from Overhead Light Fixture

[JustADude]

Short story - fixture has two bulbs. When two florescent bulbs (60 w equivalent) are in the fixture and the switch is off the are still flickering. However, if I replace one of the bulbs with an ol' school incandescent bulb the flickering goes away when the power is off. The flickering is also present if there is only one florescent bulb plugged into the fixture.

I am probably forgetting to post some other helpful information, but does anyone have any thoughts about how to fix this problem so I can use two florescent bulbs in the fixture. The flickering is really violent looking some of the florescent bulbs appear to even have flashes of blue and purple and white. Tried several different florescent bulbs to make sure there wasn't a problem with the bulbs.

Thanks again.

[HayZee518]

flourescent tubes, bulbs all use a tiny droplet of mercury to fire the bulb. a heater element heats the mercury droplet into a gas which ionizes when high current is applied. once the ionized current flow is established the current drops to a low figure and the bulb, tube continues to conduct and produce light. its quite possible that even after the current is cut off that the gas which is now heated continues to excite the phosphor coating inside the tube and causes different color spectrums as it cools down.

[dkpbxman]

Is there anything else in the circuit?

I had the same problem with my outside porch lights when I replaced the Halogens with Energy Star floods.

That circuit also has a timer wired into it and I was told that the timer draws a very minimal current for its own operation even while the circuit is switched off. The new floods were barely activated by that current and therefore obviously flickered while I never noticed it with the Halogens.

Photo-cells will also do it.

[HayZee518]

Photocells, motion sensors have an electronic circuit which must always be hot - even when the load is switched off. Three wires are used. Black and White, always hot goes to the device. The load off the sensor the red wire can be switched through a single pole or three way switch(s) to the load. Never switch the black wire or you'll encounter false timing of the circuit. The device will always go into self test mode if the black is switched.