GB/T 15144-1994 Performance requirements for AC electronic ballasts for tubular fluorescent lamps
Some standard content:
National Standard of the People's Republic of China
AC supplied electronir hallasts for tubular fluorescent lamps--Performance requirementsGB/T15144-94
This standard is equivalent to the old International Electrotechnical Commission standard IEC:929 (1990) Performance requirements for AC electronic ballasts for tubular fluorescent lamps.
1 Subject content and scope of application
This standard specifies the performance requirements for AC electronic ballasts for tubular fluorescent lamps with an AC power supply of less than 1000V, 50Hz or 60Hz, and an operating frequency exceeding the power supply frequency.
This standard is applicable to AC electronic ballasts for tubular fluorescent lamps that meet the requirements of GB10682 and ZBK71003 and other AC electronic ballasts for tubular fluorescent lamps that work at high frequencies. Used together with GB15143. 2 Reference standards
GB10682 Tubular fluorescent lamps for general lighting
GB2828 Count sampling procedures and sampling tables for batch inspection (applicable to inspection of continuous batches) GB2829 Count sampling procedures and sampling tables for periodic inspection (applicable to inspection of stability of production process) GB15143 Requirements and safety requirements for AC electronic ballasts for tubular fluorescent lamps GR191 Pictorial symbols for packaging, storage and transportation
ZBK71003 Single-ended internal start fluorescent lamps
3 Terms and symbols
3.1 Ballast lumen factor
The ratio of the luminous flux of the lamp when it is matched with the ballast under test at the rated power supply voltage to the luminous flux of the lamp when it is matched with the reference ballast under the rated power supply voltage and rated power supply frequency. 3.2 Reference ballast
A ballast designed specifically for testing ballasts and screening reference lamps. The main feature is that it has a stable voltage-current ratio at rated frequency and is relatively unaffected by changes in current, temperature and ambient environment. 3.3 Base lamp
A lamp specially selected for testing ballasts. When the lamp is matched with a reference ballast and works under specified conditions, its electrical characteristics should be close to the nominal values specified in the relevant lamp standard.
3.4 Calibration current of reference ballast
The current value used as the basis for adjusting and calibrating the ballast current. 3.5 Line power
The total power consumed by the combination of ballast and lamp at the rated supply voltage and rated supply frequency of the ballast. 3.6 Line power factor
Approved by the State Administration of Technical Supervision on July 7, 1994 and implemented on January 1, 1995
GB/T 15144 -- 94
The power factor of the combination of ballast and lamp (one or more). 3.7 High power factor ballast
Ballast with a line power factor of 0.85 or above. Note: The value of 0.85 has taken into account the effect of current distortion on the power factor. 3.8 High audio impedance ballast
Ballast with impedance values in the range of 250 to 2000 Hz that meet the requirements of 4.11. 3.9 Preheat start
The lamp is triggered to start only after the lamp electrodes are heated to the electron emission temperature. 3.10 Non-preheat start
The lamp electrodes do not need to be heated, and the high open circuit voltage is used to cause the electrode field emission to trigger the lamp to start. 3.11 Pre-start time
For non-preheat start ballasts, it refers to the period of time when the lamp current is less than or equal to 10mA after the power switch is turned on. 3.12 Low distortion ballast
Ballast with harmonic content that meets the requirements of Table 1 in 4.9.1. 3.13 Symbols
Line power factor symbol: 1
If the power factor is less than 0.95 and leading, a letter "\C" should be added after the number, for example: 0.90C; b.
The symbol of the ballast meeting the requirements for rated impedance is: L; The symbol of the ballast is low-distortion type: H; The symbol of the ballast is not low-distortion type: DU;
Line power symbol: P.
4 Technical requirements
4.1 The ballast works in conjunction with the fluorescent lamp. When the voltage is 90% to 110% of the rated power supply voltage and the ambient temperature is The lamp can be satisfactorily started when the ambient temperature is 10~35℃, and the lamp can work normally when the ambient temperature is 10~~50℃. 4.2 Starting
When the lamp is used under normal conditions, the ballast should start the lamp and shall not cause damage to the lamp performance. 4.2.1 Ballast using controlled current for preheating start 4.2.1.1 When each lamp electrode is replaced by a non-inductive resistor that meets the requirements, the minimum total effective heating current provided by the ballast shall comply with the specified time/current limit (see Appendix A). The maximum effective heating current shall not exceed the specified preheating current limit at any time during the preheating process. During preheating 4.2.1.2 During the preheating period, the open circuit voltage between the lamp and the replacement resistor shall not exceed the specified maximum value. After the preheating process is completed, the voltage value shall not be lower than the specified minimum lamp starting voltage. Before the above open circuit voltage reaches the specified minimum lamp starting voltage, if the preheating current flowing through the above replacement resistor is interrupted, the time taken for the voltage to rise to the minimum starting voltage shall not be greater than 100ms; if the rise time is greater than 100ms, the preheating current shall not be interrupted and it shall not be lower than the specified absolute minimum value of 1. (See Appendix A). The crest factor of the open circuit voltage shall not exceed 1 .8. During the minimum preheating period, no voltage peak, even extremely narrow, which does not affect the effective value, shall be generated.
4.2.2 Ballast using control voltage for preheating start 4.2.2.1 The ballast shall provide the required cathode preheating voltage, cathode operating voltage and lamp starting voltage to the lamp. After applying the rated power supply voltage, the effective value of the cathode preheating voltage provided by the ballast to the cathode ridge resistor shall be within the specified preheating voltage limit range. If the maximum cathode preheating current complies with the provisions of 4.2.1, the cathode preheating voltage is allowed to exceed the maximum cathode preheating voltage limit.
GB/T 15144-94
The minimum time for applying the cathode preheat voltage shall not be less than 0.4s. 4.2.2.2 The ballast shall provide the lamp with a starting voltage according to the specified value. The starting voltage may be applied simultaneously with the cathode preheat voltage, or it may be increased to this value after an interval of .4s, but any voltage applied before 0.4s must be lower than the voltage level that can cause the lamp to start, that is, it complies with the provisions of 4.2.1.2.
4.2.3 Ballasts for non-preheat starting
4.2.3.1 When the ballast is used in conjunction with a reference lamp, and there is no grounded metal body near the lamp that may assist in starting, the cumulative glow discharge time generated during the starting period shall not exceed 100ms. When the lamp current reaches 80% of the nominal lamp current, the glow discharge stage is considered to be over. 4.2.3.2 Open circuit voltage
The open circuit voltage shall comply with the specified value.
Note: In the case of additional cathode heating during the starting process, the open circuit voltage may be reduced as long as the glow discharge phase is less than 100ms. 4.2.3.3 Ballast impedance
At 92% of the rated voltage, the lamp is replaced by a non-inductive resistor RL of the specified value. When replacing the lamp cathode, the current provided by the ballast shall not be less than the specified minimum value. 4.2.3.4 Cathode current
Non-preheating ballasts may provide partial cathode heating during the lamp starting process, but the cathode current value shall not exceed the maximum value specified in the relevant standards.
4.3 Lumen factor
When the ballast is operated with a lamp at the rated supply voltage, the lumen factor of the ballast shall not be less than 95% of the value specified by the manufacturer. If the specified lumen factor is less than 0.9, proof shall be provided that the performance of the lamp will not be impaired when operated with such a ballast. 4.4 Line power
When the ballast is matched with the reference lamp at the rated power supply voltage, the line power shall not be greater than 110% of the nominal value. 4.5 Lamp current
The ballast shall limit the current value supplied to the lamp. At the rated power supply voltage, the current supplied to the lamp when the ballast is matched with the reference lamp shall not exceed 115% of the lamp current value when the reference ballast is matched with the lamp.
4.6 Line power factor A
When the ballast is matched with the lamp (one or more) at the rated power supply voltage and rated frequency, the line power factor shall not differ from the nominal value by more than ±0.05.
4.7 Power supply current
When the ballast is matched with the lamp at the rated power supply voltage, the power supply current shall not differ from the nominal value of the ballast by more than ±10%. 4.8 Maximum current introduced into the cathode
In normal working conditions, when the power supply voltage is any value between 92% and 106% of the rated value, the current flowing through any wire of the cathode terminal shall not exceed the specified value.
4.9 Current waveform
4.9.1 Power supply current waveform
The ballast and lamp (one or more) operate at the rated power supply voltage. After the lamp reaches a stable working state, the harmonic content in the power supply current of the low-distortion ballast (with L mark) shall not exceed the limit value specified in Table 1. The harmonic content in the power supply current of the ballast with "H" mark shall not exceed the limit value specified in Table 2.
4.9.2 Lamp working current waveform
GB/T15144-94
Table 1 Maximum value of harmonic content in the power supply current of the ballast with "L" mark (expressed as a percentage of the ballast fundamental current) %
Table 2 Maximum value of harmonic content in the power supply current of the ballast with "II" mark (expressed as a percentage of the ballast fundamental current) %
No restriction
Under the rated power supply voltage, the ballast and the lamp work together. When the lamp reaches a stable working state, the waveform of the lamp current shall meet the following requirements:
While the power supply voltage passes through the zero phase, the envelope wave of the lamp current shall not differ by more than 4 in each continuous half cycle: b. The maximum ratio of the peak value to the root mean square value of the lamp current shall not exceed 1.7. The crest factor of a single high-frequency ballast shall not exceed 1.7. When modulating high frequency at the network power frequency, the maximum crest factor of the modulated waveform lamp current shall not exceed 1.7. Note: The crest factor of high frequency current is the ratio of the current peak value of the modulated or unmodulated envelope wave to the effective root mean square value of the current. 4.10 Magnetic shielding
The ballast shall have effective magnetic shielding.
4.11 Acoustic impedance
The ballast with the audio symbol Z shall meet the following requirements: For each frequency signal between 400 and 2000 Hz, when the signal voltage ratio is equal to 3.5% of the rated power voltage of the ballast, the impedance of the ballast and the lamp matching at the rated frequency should be inductive. Its resistance value is equivalent to such a resistor: when operating at the rated voltage and rated frequency, it consumes the same power as the lamp and ballast combination. For signals between 250 and 400 Hz, the impedance value should be at least half of the minimum impedance value required for signals with frequencies between 400 and 2000 Hz.
4.12 Withstand transient overvoltage in power supply Ballast should not be affected by transient overvoltage in power supply or damaged. 4.13 Abnormal state
Ballast should be able to operate normally after 1 hour in each of the following abnormal states: Lamp open circuit:
h. Lamp does not start.
4.14 Durability
GB/T 15144-94
After the ballast passes the test specified in 5.14, it should still be able to start the lamp normally and operate for more than 15tnin. 5 Test method
5.1 General requirements for test
5.1.1 Test environment
Each test should be carried out in a room without convection airflow, with an ambient temperature of 20-27℃ and an air relative humidity of no more than 65%. For the test items requiring lamp E to be stable in performance, the temperature around the lamp should be 23-27℃ and the change during the test should not be greater than 1℃. 5.1.2 Supply voltage and frequency
5. 1.2.1 Test voltage and frequency
The ballast under test should operate at its rated voltage, and the reference ballast should operate at the rated voltage and rated frequency. 5.1.2.2 Stability of power supply voltage and frequency The error of power supply voltage and frequency should be kept within ±0.5%. During actual measurement, the voltage should be adjusted to within ±0.2% of the specified test voltage.
5.1.2.3 Power supply voltage waveform
The total harmonic content of the power supply voltage shall not be greater than 3%. The definition of harmonic content is the sum of the root mean square values of each harmonic component, with the fundamental wave as 100%.
5.1.3 Magnetic effect
There shall be no magnetic objects within 25mm of the reference ballast or the ballast under test. 5.1.4 Installation and connection of reference lamp
To ensure the maximum consistency of the electrical parameters repeatedly provided by the reference lamp, the lamp shall be installed horizontally and always kept in the test lamp holder. Under the condition that the ballast terminals can be identified, the polarity of each connecting wire when the reference lamp is connected to the circuit shall remain the same as that during aging. 5.1.5 Stability of reference lamp
a. Before measurement, the lamp shall be in a stable working state without flashover. b. Before and after each series of tests, the characteristics of the lamp shall be checked immediately according to Appendix C. 5.1.6 Instrument characteristics
The accuracy of the electrical instrument used shall not be less than Class 0.5. Voltage circuit
The current flowing through the instrument connected in parallel with the lamp shall not be greater than 3% of the normal working current. b. The impedance of the instrument connected to the lamp in the current circuit
should be low enough, and its voltage drop should not exceed 2% of the actual lamp voltage. If the measuring instrument is connected to the parallel heating circuit, the total impedance of the instrument shall not be greater than 0.52. c. The instrument for effective value measurement
should match the operating frequency and have basically no error caused by waveform distortion. Care should be taken to ensure that the capacitance of the instrument to ground does not interfere with the operation of the device under test. 5-1. Unless otherwise specified, the tests shall be carried out in the order of the clauses 5.2 Start-up (4.2) Test
5.2.1 Preheating start-up (4.2.1, 4.2.2) The test is carried out according to the circuit in Figure 1, and the test instrument is an oscilloscope. When the ballast is used in parallel with several lamps, the equivalent simulated resistance (R) of the cathode should be connected to all relevant contacts, and the measurement is carried out in the order of each pair of replacement resistors representing one lamp. When the ballast is used in series with the lamp, the cathode replacement resistor is used to replace the cathode of the two lamps during measurement. The output winding of the isolation transformer in the ballast is grounded. If there is no isolation transformer in the ballast, an isolation transformer should be inserted on the input side, and the total open circuit voltage should be measured between the two lamps. GB/T 15144-94 During the preheating period, the open circuit voltage should be lower than or equal to the voltage value specified for one lamp. During the ignition period, the parallel circuit voltage should be lower than the minimum voltage value specified for two lamps in series. If the starting auxiliary part is used, the voltage should comply with the specified value. For ballasts with preheating control current, if the preheating current is a current with a stable RMS value, the effective value of the preheating current can be determined by testing a single high-frequency cycle with an oscilloscope to determine the effective value and crest factor. It can also be measured directly with appropriate instruments. For variable currents, the effective value of the preheating current is regarded as equal to the effective value of a certain RMS stable current with the same heating effect. For details, see Appendix A (Supplement). Preheating time t. It can be calculated by the formula (A1) given in Appendix A. Power supply
Figure 1 Test circuit for controlling current for preheating start ballast B - ballast to be tested, R. Cathode equivalent simulated resistor ll;div-5.2.2 Non-preheating start (4.2.3) test is carried out according to the circuit in Figure 2. Start
(a) Open-drop voltage test line
(b) Ballast muscle resistance test line Lu
Test instrument
(c) Cathode current test circuit
Figure 2 Test circuit for non-preheating start ballast B - ballast to be tested; R Cathode equivalent simulated resistor; RL replaces lamp resistor; Ri--cathode replacement resistor; I)-lamp;div-test instrument GB/T 15144-94bZxz.net
5.2.2.1 Open circuit voltage (4.2.3.2) test is carried out according to the circuit in Figure 2 (a). Use a non-inductive resistor R that meets the specified value. Replace each lamp cathode and measure the open circuit voltage with an oscilloscope. When two lamps are connected in series, the open circuit voltage supplied to each lamp should be measured in turn. Replace one lamp with a reference lamp and replace the cathode of the other lamp with a replacement resistor. The open circuit voltage is measured between the two resistors. Both measured values should meet the specified values. 5.2.2.2 The ballast impedance (4.2.3.3) test is carried out according to the circuit of Figure 2 (b). Use a non-inductive resistor R that meets the requirements to replace the lamp, and a non-inductive resistor R. Replace each cathode of the lamp. When the power supply voltage is 92% of the rated power supply voltage, the current provided by the ballast shall not be less than the specified minimum value. 5.2.2.3 The cathode current (4.2.3.4) test is carried out according to the circuit of Figure 2 (c). For non-preheat start ballasts that provide partial cathode heating, when measuring the cathode current, the resistance of the cathode replacement resistor R is calculated according to formula (1):
R =11/2. 11.
Where: R;--replacement resistor,;
1. Nominal value of the lamp operating current, A.
5.3 Lumen factor (4.3) test
The lumen factor is calculated according to formula (2):
Where, u-ballast lumen factor,
Φ——luminous flux when the lamp works with the reference ballast; ——luminous flux when the lamp works with the ballast under test. 5.4 Line power (4.4) Test
The power of the circuit is measured by the circuit diagram of Figure 3, and the voltmeter is open during the measurement. Output
A—Ammeter: VVoltmeter WPower meter: B—Ballast to be tested, J)—Reference lamp5.5Lamp current (4.5) Test
The lamp current is tested according to the circuit diagram of Figure 4.
GB/T 15144- 94
Figure 4 Measurement circuit of current waveform
B—Ballast to be tested; D—Reference lamp; R—Current sampling resistor: div1Waveform analyzer or selective voltmeter idiv2Oscilloscope or current manipulator5.6 Line power factor (4.6) Test
The power factor of the line is measured according to the circuit diagram of Figure 3. The line power factor is calculated according to formula (3):
A=W/VI
Where: -
Line power factor;
Line power, W:
Input voltage, V,
Input current, A.
5.7 Power supply current (4.7) test
The power supply current is measured according to the circuit in Figure 3.
5.8 Test of maximum current introduced into the cathode (4.8) p
(3)
The maximum current introduced into the cathode is measured according to the circuit in Figure 3. Use an oscilloscope or other suitable instrument to measure at each cathode terminal. The current sampling resistor connected in series with the cathode loop should be small enough so that the voltage drop it produces is no more than 2% of the actual voltage of the loop in which it is located. 5.9 Current waveform (4.9) test
The current waveform is measured according to the circuit in Figure 4.
The harmonic content of the power supply current shall be measured by a selective voltmeter or waveform analyzer. The sampling resistor R connected in the circuit shall comply with the provisions of 5.1.6.
The results of the selective voltmeter or waveform analyzer for any harmonic shall not be significantly affected by other harmonics. When calculating the test results, the maximum distortion of the power supply current shall be taken into account. In case of doubt, a distortion-free power supply shall be used.
The peak value of the lamp current shall be measured by a calibrated quiescent device or other suitable instrument. 5.10 Magnetic shielding (4.10) test
The ballast and lamp are matched to work at a rated voltage of less than 1 mm. After reaching a stable state, a steel sheet with a thickness of 1 mm and a length and width greater than the corresponding size of the ballast to be tested shall be placed in contact with the bottom surface of the ballast and at a distance of 1 mm from the other surfaces. During this process, the lamp current is measured. The lamp current value shall not cause an error of more than 2% due to the presence of the steel sheet. 5.11 Audio impedance (4.11) test
The audio impedance test is carried out according to the circuit shown in Figure 5.
GB/T 15144-94
Using the circuit shown in Figure 5, the system acoustic impedance Z can be fully determined. R1 and R2 are two resistors in the bridge, and at least R is not a critical value. By adjusting R and C, a balance is obtained for a given acoustic impedance selected on the waveform analyzer, and it can be obtained that:
Z=R,R,(1/R+μC)
If R2-200 0000,R,=50, then
Z-10°(1/R+ jaC)
Note: (1) In Figure 5, if the corresponding power supply has a low internal resistance to the current of the other power supply, 7,,Z can be omitted. (2) During the test, the radio interference suppression capacitors of small capacity (Q.2μuF (total)) that may be installed in the ballast may be disconnected: Power supply 5U(t0)Hz
Signal generating unit
7EGH7-700GH7
200 000g
Figure 5 Acoustic impedance test circuit
A-power supply voltage regulator; B-lamp/ballast combination to be tested, Z-impedance, high enough for 50(60)Hz, low enough for 250Hz to 2 000Hz (for example 15A resistor + 16u capacitor); Z-impedance, low enough for 50(60)Hz, low enough for 250Hz to 2 00QHz is high enough (for example, 20mH inductance), div-selective voltmeter or waveform analyzer 5.12 Transient overvoltage (4.12) test
The transient overvoltage in the power supply is shown in Table 3. Table 3
Pulse type
Asymmetric type
Symmetric type
Asymmetric type
Pulse amplitude
Rise time
Note: 1) Minimum pulse repetition rate is 1/10Hz. a.
Low speed high energy pulse test:
The pulse test is carried out according to the relevant characteristics specified in Table 3. Pulse width
Source impedance
Repetition rate
1/8 network power supply
1/5 network power supply frequency
(5)
Effective energy
Pulse phase position: within 1min Slowly turn the knob from one extreme phase to the other and then slowly turn it back to the original position within 1 minute. At this time, the pulse phase changes continuously from 80° to 460°. Pulse polarity: positive and negative.
GB/T 15144- 94
Because a group of fast and continuous high-energy pulses may overload the components in the power supply part of the ballast, it is sometimes necessary to add a pulse repetition time of up to 10%.
Because this test may damage some components, the test report should state the repetition time used and the actual number of pulses applied. Damaged components should be replaced.
h. Fast low-energy pulse test:
The pulse test is carried out according to the relevant characteristics specified in Table 3. Pulse phase position: Slowly turn the knob from one extreme phase to the other extreme phase ...
5.13 Abnormal state (4.13) test
. Open circuit lamp test
Under 1.1 times the rated power supply voltage, the ballast works with the corresponding lamp. First, disconnect the lamp from the ballast without turning off the power supply for 1 hour, and then connect the working lamp. The lamp should be able to start and work normally; at least it should be the case when the lamp is turned on again; b. Lamp non-starting test
Under 1.1 times the rated power supply voltage, the ballast is not connected to the lamp, and an appropriate simulated cathode resistor is connected to the position connected to the lamp cathode for 1 hour, then the resistor is removed and the corresponding lamp is connected. The lamp should be able to start and work normally, at least it should be the case when the lamp is turned on again. 5.14 Durability (4.14) test
a. The ballast is first placed at the lower limit ambient temperature for 1 hour, and then placed at an ambient temperature of temperature t for 1 hour, and 5 cycles are carried out: if the lower limit value is not specified, 10℃ is used as the storage temperature; b. Then the output end of the ballast is open, and the switch is repeated 1000 times at the rated power supply voltage, and 30% is turned on and off each time. e. Finally, the ballast and the corresponding lamp are matched to work for 200 hours at the rated power supply voltage and the ambient temperature at which the shell temperature reaches t. Then the temperature is restored to room temperature, and the ballast can make the lamp start normally and work for 15 minutes. During the test, the ambient temperature around the lamp is 25±5. 5.15 Ambient temperature (4.1) test
The ballast and the lamp are matched to work at the rated voltage, and the ballast works for 4 hours at an ambient temperature of 50℃. The shell temperature shall not exceed the value. 5.16 Marking (7.1) test
The test shall be carried out in accordance with the method specified in 6.3 of GB 15143. 6 Inspection rules
6.1 In order to inspect whether the ballast complies with the provisions of this standard, the manufacturer shall carry out acceptance inspection and routine inspection. 6.2 Acceptance inspection shall be carried out in accordance with the provisions of GB2828. 6.2.1 The items belonging to acceptance inspection are 4.1, 4.3, 4.4, 4.6, 4.7 and 7.1 (appearance). 6.2.2 The sampling plan adopts the secondary normal inspection sampling plan, the acceptable quality level (AQL) is 4.0, and the general inspection level I is adopted. 6.3 Routine inspection shall not be less than once a year and shall be carried out in accordance with the provisions of GB2829. 6.3.1 The items belonging to routine inspection are 4.2.4.5, 4.8, 4.94.10, 4.11, 4.12, 4.13, 4.14 and 7.1 (firmness). 6.3.2 The sampling plan adopts ~-time sampling method, the discrimination level DL is , and the unqualified quality level (RQI.) is 50. The discrimination array is A, --1, R.-2.
7 Marking, packaging, transportation, storage
7.1 Marking
7.1.1 In addition to the markings in accordance with Chapter 6 of GB15143, the ballast should also have the following clear and durable markings: a, line power factor input;
letter H;
GB/T 15144-94
c, starting type, i.e. preheating type or non-preheating type; d. Ballast lumen factor and line power. 7.1.2 If necessary, the following marks should be marked:
2, the predetermined output frequency at rated voltage under working conditions with and without lamps: b. the limit value of the ambient temperature range for satisfactory operation of the ballast at rated voltage (or voltage range): c. whether the ballast needs a starting aid
d. Many letters.
7.2 Packaging
7.2.1 Independent ballasts should be packaged separately, and the packaging box should have a mark and packaging date that complies with the relevant provisions of 7.1 and Chapter 6 of GB15143.
7.2.2 The packaging box should be firm and have moisture-proof measures. 7.2.3 The packaging box should have the following marks
a: Marks that comply with the relevant provisions of 7.1 and Chapter 6 of GB15143: b, product quantity;
c Packing date;
d, standard code.
7.2.4 Each box or carton of ballasts shall be accompanied by a product manual and a certificate of conformity, and the outer packaging box shall also have relevant marks in accordance with the provisions of GB191.
7.3 Transportation
During transportation, it should be protected from rain, snow and strong vibration. 7.4 Storage
The ballast should be placed in a ventilated room with a humidity not exceeding 85%, and there should be no corrosive gas in the air. A1 Methods and requirements for lamp starting
A1.1 Preheating start
GB/T 15144— 94
Appendix A
Description of starting conditions
(Supplement)
The passband adopts the method of controlling cathode current for preheating or controlling cathode voltage for preheating to provide the starting of preheated cathode lamps. Regardless of which method is used for starting, the following requirements shall be met; a. Before the cathode reaches the electron emission state, the open circuit voltage between the two ends of the lamp or between the lamp and the starting auxiliary device should be kept below the level of the lamp photocurrent that causes damage to the cathode: after the cathode reaches the emission state, the open circuit voltage should be high enough to start the lamp quickly without repeated starting; h
. When the cathode has reached the emission state, if the open circuit voltage needs to be increased to start the lamp, the transition process from low to high open circuit voltage must be completed while the cathode is still at the emission temperature; d During the cathode preheating stage, the preheating current or preheating voltage shall not be too large or too high to cause the emission material on the cathode to be damaged by overheating. In a circuit with multiple lamps in series, if a starting capacitor is used to shunt part of the current of the multi-lamp combination, and the full open circuit voltage is applied to the lamp that has not been shunted, the capacitance value of the starting capacitor is related to the glow current that occurs at the beginning of the start, and the capacitance value of the starting capacitor should be balanced with the smoothness of the start and other working characteristics of the lamp and the ballast. A1.2 Non-preheat start
Non-preheat start is to start the lamp by using the electrode field emission effect caused by the instantaneous high open circuit voltage applied to the two ends of the lamp. The level of the open circuit voltage and the source impedance of the ballast determine the time required for the lamp to transition from the glow current stage of discharge to the complete arc discharge state.
One of the reasons for the blackening of the lamp end and premature damage is the excessively long continuous glow discharge current generated during the starting process. In order to minimize the destructiveness of the glow discharge current, it is necessary to ensure that the provided support current is the minimum value, and the ballast can drive the lamp quickly through this stage without causing repeated starting time exceeding 100ms. A2 Explanation of starting (4.2)
A2.1 Preheat start
A2.1.1 Ballast effective preheat current and emission time (t) for preheating using controlled current Minimum value of effective preheat current.
The heat required to make a certain type of cathode reach the minimum emission temperature can be expressed by time, current and a constant determined by the physical characteristics of this type of cathode. This relationship is expressed by formula (A1): tu/(*—i\)
where; t.
The time to reach the emission state, s (0.4s\): α-——constant of a specific type of cathode:
i———the minimum effective preheating current required to obtain t, A! i-——the minimum absolute value required to reach the emission state, A\. (A1)
Note: 1) It is usually not advisable to use a preheating time of less than 10.4s to reach the emission state, because practice has shown that it is not always possible to use the cathode to achieve sufficient preheating within this time.
2) This refers to the case where it is assumed that the time for applying the preheating current from the start of the aging state is long enough (such as more than 30s).
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