MIL-STD-1275 Characteristics Of 28 Volt Dc Input Power To Utilization Equipment In Military VehiclesThis standard defines the operating voltage limits and transient voltage characteristics of the 28 VDC electrical power at the input power terminals to the utilization equipment connected to the electrical power distribution system on military ground vehicle platforms.

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MIL-STD-1275E

Figure 11. Sample test circuit for immunity to injected voltage surges.

The voltage waveform injected on the power line(s) of the EUT shall simulate the voltage surge shown in Figure 4. The voltage surge parameters are shown in Table I. Energy emitted from the transient surge generator shall be limited to 60 Joules.

Table I. Positive voltage surge test parameters.

Operating Voltage (Vnom)

Amplitude

(Vpeak)

Rise Time (ms)

Duration

(ms)

Source Impedance (mΩ)

Number of Pulses

Time

Between Pulses (s)

30 -0/+1

100 -0/+10

1 < t < 10

50 -0/+5

500 -25/+0

Prior to connection of the EUT, the test operator shall verify the amplitude and duration of the voltage surge specified in Table I with a non-inductive load whose resistance is matched to the source impedance of the transient generator.

Verify the EUT operates as specified while subjected to the voltage surges. Any deviation from normal operation shall be recognized as a failure of the EUT.

5.3.3.2.2 Emitted voltage surges.

The EUT shall be supplied power by a source set to the nominal 28 VDC operating voltage. The test operator shall measure voltage surges emitted by the EUT using a test setup similar to Figure

10. The test operator shall exercise function(s) of the EUT capable of producing surges. Each surge-producing function shall be exercised a minimum of thirty-two (32) times in order to give a reasonable probability that the maximum surge voltage is recorded.