MIL-PRF-28776 Relays, Hybrid, Established Reliability, General Specification ForThis specification establishes the general requirements for relays that use a combination of solid state circuit input elements functioning with an electro-mechanical relay that performs the switching functions associated with control system applications \(see 6.1\). These relays are designed to operate in low and medium power switching circuits with contact ratings up to 1 ampere alternating current \(ac\) or direct current \(dc\). The failure rate level is established at a confidence level of 90 percent for qualification and 60 percent for maintenance of qualification based on 100,000 cycles at +125┬░C under rated load conditions specified herein. Excludes time delay relays. CAUTION: The use of any coil voltage less than the rated coil voltage will compromise the operation of the relay. CAUTION: Pick-up, hold, and dropout voltages are for test purposes only and are not to be used as design criteria. For additional application and caution information, see 6.1.

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MIL-PRF-28776F

FIGURE 7. Typical transient voltage.

4.8.8 Thermal shock (see 3.13). Relays shall be tested in accordance with method 107 of MIL-STD-202. The

following details and exceptions shall apply:

Special mounting: Relays shall be suspended in the test chamber by twine, test socket, or other nonheat-

conducting material. Test leads may be used for mounting; however, they shall not exceed the diameter or

cross section of the device lead. (NOTE: When test sockets are used, the surface of the header shall not

directly contact with the surface of the socket and the leads of the socket shall not exceed the diameter or

cross section of the device lead).

Test condition: B, except exposure time at temperature extreme during the fifth cycle shall be for 2 hours

each.

Measurements at each temperature extreme during steps 1 and 3 of this fifth cycle at the end of each

temperature exposure, and with the relays still in the conditioning chamber, the pickup, hold, dropout, turn-

on, and turn-off voltages, and turn-on and turn-off times, shall be measured as specified in 4.8.7.2, 4.8.7.4,

and 4.8.7.6 respectively. Pickup, hold, and dropout voltages shall be measured in any position.

Examination after test: Relays shall be visually examined for cracking, peeling, and flaking of the finish,

and the insulation resistance and dielectric withstanding voltage shall then be measured as specified in