Downloaded from https://www.everyspec.com MIL-STD-1311D OPERATION OF RECTIFIERS Each tube shall operate satisfactorily and without rejectable arc-backs in a rectifier circuit under the conditions specified. The criteria for rejectable arc-back and their detection shall be as specified in 1 to 3, inclusive, as applicable, or as specified. When the test conditions specify circuit constants, the dc current in the load resistor shall be within the limits specified. The duration of test shall be sufficient to obtain indication of satisfactory operation.
For mercury-vapor rectifiers, the cathode shall be allowed to heat for a period of time sufficient to distribute the mercury properly in the bulb. Inductive loading shall not be used. Unless otherwise specified, rejectable arc-backs do not apply to life tests. 1. Receiving-type rectifiers. In the operation of receiving-type rectifiers, a rejectable arc-back is one which has a peak reverse current at least 3.5 times the rated peak steady-state anode current per anode and which occurs after a delay of at least 5 input frequency cycles from the time of application of anode voltage.
(This delay distinguishes arcs attributable to the tube from those which result from transient instability of the test equipment.) The arc-back detector shall have a maximum charging time constant of 0.5 millisecond and shall be capable of detecting a single rectangular peak of 0.5 millisecond duration with an amplitude of 3.5 times the rated peak steady-state anode current per anode. The minimum test time shall be the time required for the TUT to reach the minimum operation current, Io, specified on the TSS. The tube may be preheated at rated heater or filament voltage at the option of the manufacturer. This is not a destructive test. 2. Gas rectifiers.
In the operation of gas rectifiers, a rejectable arc-back is one which has a current in the reverse direction whose peak value is not less than five times the peak forward anode current obtained during this test. In the test circuit, the source impedance shall be such that the peak value of the steady-state current in the shorting circuit, when all tubes are short circuited, shall not be less than 7.5 times the peak forward anode current obtained during this test. The arc-back detector shall be capable of detecting a rejectable arc current whose duration is equal to or greater than ј cycle of the frequency of the applied voltage.
Unless otherwise specified, the frequency of operations shall be 50 to 60 Hz. Qualification samples shall be operated for 1 hour. 3. Power-vacuum rectifiers. In the operation of power rectifiers, a rejectable arc-back is one which has a peak reverse current at least 3.5 times the rated peak steady-state anode current. In the test circuit, the source impedance shall be such that the peak value of the steady-state current in the shorting circuit, when all tubes are short circuited, shall be at least four times the peak forward anode current obtained during this test.
The arc-back detector shall be capable of detecting a rejectable arc current whose duration is equal to or greater than ј cycle of a cycle of the frequency of the applied voltage. The frequency of the applied voltage shall be 50 to 60 Hz. Qualification samples shall be operated for 1 hour. METHOD 1353A METHOD 1353A 1353-1 25 March 1970