High frequency fluorescent lamp comes out since 1990 year. Its distinct features are fine tube, small current and high power. Because of the above design structure, and working by the high frequency current which from the low power consumption electronic ballast, so that the work system of this high frequency fluorescent lamp is superior than the traditional in the aspects of lighting effect and photometric.
How to measure the characters of the fluorescent lamp in high frequency condition? How to verify the match relationship of the tube and ballast? These problems always trouble the fluorescent tubes manufacture enterprise and the third lab service company. Lisun Group supplies the following two solutions: IEC Standard Test Method and High Frequency Constant Current Equivalent Test Method.
1. IEC Standard Test Method
Double end fluorescent lamp adopts the IEC 60081 (GB/T10682) and the single-ended fluorescent lamp adopts the IEC60901 (GB/T17262), where in the standard of electricity parameters as in Fig 1. As we know the testing correctness of the photo & color parameters are based on the fact that the reference ballast, power and instrument in the detection circuit all comply with standards. If the reference ballast, power and instrument can’t meet the standard, that means which can not supply the tube a standard working conditions. Then, it does not only the tested electricity parameter but also the photo & color parameters will deviate from the actual value obviously.
Fig 1 Preheating Method of Cathode High Frequency Fluorescent Lamp
In Fig 1, according to IEC Standard which required the High Frequency Power Source, Adjustable Reference Ballast and Lamp Preheat Assistant Source to do the high frequency tube test.
●High Frequency Power Source (HFP-300): output power is 20～26kHz, the frequency should be kept in the range of ±2％ at working. Output power is 0～580V.
●Adjustable Reference Ballast (RB-2): impedance values of high frequency reference ballast which used by any high frequency lamp with regard to GB/T10682 (IEC 60081) and GB/T17262 (IEC60901), RB-2 conforms to the requirement of IEC60929.
●Lamp Preheat Assistant Source | Auxiliary Power Supply (LPS-1): Preheating method of cathode during the high frequency fluorescent lamp starting.
The above IEC Standard Test System is not only the necessary instruments to measure the photo & electricity parameters according to the standard of IEC 60081 and IEC60901, but also the lumen and color parameters according to the standard of IEC60929 (GB/T15144). Any national lighting electrical test center must adopt the above test system if need to do High frequency lamp such as T5 tube. The above IEC Standard Test System (HFP-300, RB-2 and LPS-1) equipped with Spectrophotometer & Integrating Test System (LPCE-1) can test CCT, CRI, Spectrum, Lumen and electricity parameters for high frequency fluorescent lamp T5.
Fig 2 LPCE-1 Spectrophotometer & Integrating Sphere Test System
2. High Frequency Constant Current Equivalent Test Method:
Even though, the above Standard Test System can totally conform to the requirement of measuring the high frequency fluorescent lamp in standard of IEC, due to the high price of this system, the small third lab service company and the most of manufactory company can't cover the high cost, Lisun Group developed HCS-105A which is an equivalent test method comparing to IEC method. The typical schematic as Fig 3, high frequency constant current source provides a continuously adjustable output current of 100mA ~ 500mA.
Fig 3 High Frequency Constant Current Equivalent Test Method
When connected the circuit to turn on the lights, high frequency constant current source will deliver high-voltage pulse to start the lamp, the output frequency of high frequency constant current source is in 20～26kHz. The obvious shortage of equivalent method is due to the constant current source output internal impedance is high. The large internal impedance of high frequency constant current source will cover the departure of tested lamp with respect to standard electrical parameters. It will take about 5%~30% tolerance when use LPCE-1 Fig 2 to do photo, color and electricity parameters.