i just rip out the ballast/s and replace tubes with LEDs.
I agree, LED replacements are fantastic with instant 'switch-times' and great efficiency, also not effected by cold weather which can cause traditional fluorescents a delay when switched on.
I'll give answers in the long and short, quite literally:
Short:
- The starter may not be working, needs replacing.
- The lamp it's-self may bot be working, needs replacing. (Usually a darkened tube will show this, unless cracked).
- Dimmer switches don't work on fluorescent lamps, so don't use them.
Long:
Traditional fluorescent lamps consist of a tube which contains a mercury-based gas. The circuit starts with a 'choke'/'ballast' (basically a large coil of wire) which serves many functions which include:- current limiting, stepping-up voltage, etc. They then have a 'starter' which basically uses a bi-metallic switch and begins closed-circuit allowing larger currents (albeit limited by the choke) to heat-up the electrodes and also the gas inside the tube, resulting in ionisation and therefore a lower impedance between electrodes. The bi-metallic strip contained within the starter will now be at a higher temperature due to the current flowing through it, resulting in the two dissimilar metals which make up the bi-metallic switch to expand at different rates, causing it to bend and therefore break-contact (go open-circuit) which results in the electrons taking the new path of least resistance which is through the ionised gas between electrodes (through the tube). The electrons passing through the tube release photons (albeit not yet viable / UV) which collide with the phosphorus coating on the inside of the tube, producing visible light.
By understanding this process, there are several possible explanations for the flickering / strobe effect:
- The starter isn't working properly, most likely the coil within it to maintain temperature has gone open-circuit, resulting in the bi-metallic switch opening, then cooling quickly, then closing, then heating, then opining... and repeating. The starter often has a small coil between the contacts which even when 'open-circuit' allows enough current to build in order to produce heat, in order to maintain the temperature of the bi-metallic switch so that it doesn't cool and therefore change back to closed-circuit.
- The lamp it's-self (tube) isn't working properly, potentially due to a loss of gas. When the gas is ionised, it passes current for a short period of time while sufficiently heated, before cooling where ionisation is lost and the current-flow stops; the starter (now passing no current) cools until closed-circuit, then heating the gas resulting in ionisation... repeating in a flickering / strobe effect.
- Dimmer switches use an auto-transformer to vary the voltage to the lamp. While this is fine for some other types of lamps, florescents cannot be dimmed. This is because using basic Ohm's law, a reduction in voltage will result in a lower power-consumption naturally (Watts). The power consumption will directly effect the heating of the starter, and by 'dimming the lamp' (reducing the voltage) the starter will slowly-warm, then quickly cool, then slowly-warm, quickly-cool, continuously; resulting in a open-circuit, closed-circuit, open-circuit, closed circuit, etc. This will be seen as a strobe / flickering effect.
