In the past the ‘on-time’, or the time it takes for the light bulb to light up completely, was a problem. Today, this is still somewhat of an issue. CFLs require pre-heating of the electrodes, which could take up to a second in the past. When people would flip the switch it would take a second for the bulb to turn on. That second of no light was a lot of time when you had already flipped the switch and expected the light to shine.
In order to minimize this start time, there are two options. The first and quickest way to do this is called Instant Start. By putting a slightly higher voltage in the ballast, the light will turn on when the switch is flipped. At this point it is still not stable because the lamp is not at equilibrium, but at least some light will come on in the beginning. In approximately the first minute the light will probably continue to increase in intensity.
The Rapid Start System had an average startup time of about 750-1000 milliseconds. Now, with the new electronic ballasts and the program start it can be done in about 200 milliseconds. The light will come on faster and is better than the original Rapid Start. This amount of time is pretty much unidentifiable by the human eye, the light comes on essentially instantaneously.
There have been so many enhancements to CFLs over the years including no flickering, faster start time, good light output, more shapes and sizes, it is difficult to understand why people still worry about them. What about safety? The use of high frequencies have good and bad qualities in CFLs. High frequencies help start the lamp easier, however when the lamp fails it does not go out as easily – the lamp is not extinguished right away. This is referred to as the ‘end of life’ problem with the latest version of electronic ballast. In the past the ballasts did not have the ‘smarts’ to know when they were failing, continuing to strike the fail lamp which could cause them to overheat. Today when the light begins to fail, it will simply shut off and there is no safety issue associated anymore.