T5, the T8 series electronic ballast is about % of the input power.
Because the basic principle of electronic ballast is similar, electronic ballast is similar in its own power. But electronic ballast and lamp tube should match, 21W electron ballast is connected 21W lamp tube, cannot receive 28W, otherwise it is possible to work abnormality, produce compare big power consumption
I used to use an electronic ballast analyzer to measure this, and remember that the actual power of the T5 is about 3W from the power of the lamp
Happy to answer your question: In theory cannot use of electric light source directly, also is cannot use the alternating current (ac) light sources are used rectifier, because of high requirement of the voltage stability of the light source, an alternating current wave problems lead to voltage instability will greatly reduce the service life of the light source, actually it is better to remember, most energy-efficient light source need rectifier, like fluorescent lamp, LED lamp, energy saving tube and so on
