SJ 2477-1984 Test method for intermittent energization of transmitting tube filament SJ2477-1984 standard download decompression password: www.bzxz.net

Standard SJ2477-84 of the Ministry of Electronics Industry of the People's Republic of China
Test method for intermittent energization of filaments of transmitting tubes
Published on June 5, 1984
Approved by the Ministry of Electronics Industry of the People's Republic of China and implemented on January 1, 1985
Test method for intermittent energization of filaments of transmitting tubes
SJ2477-84
This standard applies to electrostatically controlled oscillation, modulation, adjustment and power amplifier tubes (hereinafter referred to as electron tubes) with anode continuous dissipation power of more than 25W, and specifies the test method for intermittent energization of filaments and the requirements for test equipment. 1 Equipment
1.1 The requirements for equipment should comply with the provisions of GB3789.1-83 "General Principles for Test Methods for Electrical Performance of Transmitting Tubes" and this standard. 1.2 The electrical schematic diagram of the equipment used to test the side-heated cathode electron tube is shown in Figures 1 and 2. When the cathode and filament of the tested indirectly heated cathode electron tube are connected inside the tube, the power supply between the cathode and filament in Figures 1 and 2 should be removed.
Component names in the figure:
G: Test tube,
R: Resistor;
B: Filament transformer,
D: Short circuit indicator,
K: Voltage interrupter,
The Ministry of Electronics Industry of the People's Republic of China issued Figure 2 on June 5, 1984
Implemented on January 1, 1985
UK: Cathode-filament power supply voltage.
SJ2477-84
1.3 The electrical schematic diagram of the equipment used to test the directly heated cathode electron tube is shown in Figures 3, 4 and 5. The electron tube on the first level of the filament power supply voltage should use Figure 3. The electron tube on the second level of the filament power supply voltage should use Figure 4. The tube with uniformly regulated filament power supply voltage should adopt Figure 5. Figure 3bzxZ.net
Component names in the figure:
G: Test tube,
B: Filament transformer;
Z: Current limiting device (resistor),
K: Voltage interrupter,
W: Current limiting device (voltage regulator)
1.4 The basic components in the electrical schematic diagram should meet the following requirements. 1.4.1 The filament power supply should ensure the specified filament voltage and filament current values. Figure 5
When testing the side-heated cathode tube, the internal resistance of the filament power supply should ensure that: when fully loaded, the change of the filament voltage at the moment of connection is not more than 10%.
When testing the direct-heated cathode tube, it is recommended to use a current limiting transformer, the internal resistance of which should ensure that: when fully loaded, the filament starting current at the moment of filament voltage connection should meet the requirements of Article 2.3. 1.4.2 The cathode-filament voltage of the indirectly heated cathode electron tube (Figure 1, Figure 2) should be connected between the cathode of the test tube and the midpoint tap of the secondary coil of the filament transformer 2
SJ2477--84
, and when the transformer has no midpoint tap, it should be connected between the cathode of the test tube and the midpoint of the voltage-dividing resistor in parallel with the secondary coil of the filament transformer (Figure 2). The resistors R1 and R2 should ensure that when the leakage current between the cathode and the filament is the largest, the voltage drop shall not exceed 5% of the specified voltage value between the cathode and the filament. If the cathode-filament voltage exceeds 10 times or more of the filament voltage, the connection of the cathode-filament voltage is allowed between the cathode of the electron tube and any tap of the secondary coil of the filament transformer. 1.4.3 The internal resistance of the cathode-filament power supply should ensure that the power supply voltage changes by no more than 5% at full load (at the cathode-filament leakage current limit).
1.4.4 The current limiting device (Figure 3, Figure 5) shall ensure the filament voltage value of the electron tube so that the filament starting current meets the requirements of Article 2.3. In order to limit the filament starting current, current limiting transformers, resistors and voltage regulators shall be used. 1.4.5 The voltage interrupter shall ensure a certain on-off cycle of the filament voltage. The on-off cycle counter can be connected to the filament circuit on the first gear or the filament circuit on the second gear. 1.4.6 The short-circuit indicator between the cathode and the filament (Figure 1, Figure 2) can use an incandescent lamp or other signal device. The resistance of the short-circuit indicator shall ensure that: when the limit leakage current is between the cathode and the filament, the voltage drop of the indicator shall not exceed 5% of the specified voltage between the cathode and the filament.
1.4.7 The ammeter or other test device used instead of the ammeter shall ensure that the filament current can be measured during the test. 2 Test preparation and test
2.1 Test preparation and test requirements:
Prepare according to the equipment operating procedures and make it work under the specified filament voltage on-off state. The accuracy of the on-off time and cycle of the filament voltage is ±25%.
The connection of the voltage interrupter K in Figure 4 should be later than K, and the delay time should be 50% of the cathode heating time. K, and K, can be disconnected at the same time.
2.2 The time and number of cycles of the filament voltage on and off of the electron tube are specified in the product standard. The time when the filament voltage is connected to the electron tube should not be less than the cathode heating time. 2.3 The electrical test specifications of the electron tube are specified in the product standard. 2.3.1 The filament power supply of the test tube should use alternating current. If there is a technical basis, the filament power supply of the test tube is allowed to use direct current. 2.3.2 If there is no other provision in the product standard of the electron tube: For the indirectly heated cathode electron tube, the filament voltage shall not exceed 10% of the limit value. For directly heated cathode electron tubes, the filament voltage shall not exceed 5% of the limit value. For directly heated cathode electron tubes, the filament starting current shall be 1.5 times the rated filament current of the tube under test. For indirectly heated cathode electron tubes, there is no limit on the starting current. If there is a requirement, it shall be specified in the product standard. 2.3.3 For indirectly heated cathode electron tubes (except for those where the cathode and filament are connected inside the tube), a limit voltage shall be applied between the cathode and the filament, and it shall be specified in the product standard of the electron tube. No voltage shall be applied to the other electrodes of the electron tube. 2.4 When testing indirectly heated cathode electron tubes (except for those where the cathode and filament are connected inside the tube), the polarity of the cathode-filament voltage shall be changed after every 500 on-off tests.
During the entire test time, the cathode-filament voltage shall not be disconnected. 2.5 Before the test and after every 500 on-off tests and after the test, the inspection of the electron tube should meet the following requirements: a. The filament is not disconnected,
b. The cathode is not disconnected,
c. There is no short circuit between the electrodes;
d. The leakage current between the cathode and the filament does not exceed the specified value. If there are special requirements, they can be specified in the product standards of the electron tube. 3
3 Test conditions
SJ2477-84
The test should be carried out under normal atmospheric conditions (ambient temperature of 15~35℃, relative humidity of 45%~75%, and air pressure of 86~106kPa) specified in GB2421-81 "General Rules for Basic Environmental Testing Procedures for Electrical and Electronic Products". Note; ① For some high-power transmitting tubes, this test can be carried out with defective electron tubes, but it must meet the requirements of Article 2.5. ② The filament of a side-heated cathode electron tube refers to a hot wire. 4
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