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

4. VERIFICATION

4.1 Classification of inspections. The inspections requirements specified herein are classified as follows:

Qualification inspection (see 4.4).

Verification of qualification (see 4.5).

In-process and conformance inspection (see 4.7).

4.2 QPL system. The manufacturer shall establish and maintain a QPL system as described in 3.3. Evidence of

such compliance shall be verified by the qualifying activity of this specification as a prerequisite for the qualification and

retention of qualification.

4.2.1 Statistical Process Control (SPC). The manufacturer shall establish and maintain a SPC system as described

in 3.3.2. Evidence of such compliance shall be verified by the qualifying activity as a prerequisite for the qualification

and retention of qualification.

4.2.2 Traceability requirements. The manufacturer shall establish and maintain a procedure whereby lot date codes

incorporate traceability. This procedure shall be approved by the qualifying activity. The following list is the minimum

required raw material/component parts and subassemblies for which traceability is applicable.

Header-contact subassembly with the lot number.

(1)

Stationary or moving contact (a contact may consist of an individual wire or a contact blade and

contact button).

(2)

Header with glass to metal sealed leads in place with the lot number.

(3)

Return spring(s).

(4)

Diodes, transistors, and FETs (as applicable) with the lot number.

Motor subassembly with the lot number.

(1)

Wound coils with the lot number.

(2)

Armature assembly.

(3)

Diodes, transistors, and FETs (as applicable) with the lot number.

4.2.3 ESDS protection program. This requirement is applicable to all manufacturers who handle ESDS component

parts and materials in the relay manufacturing or testing process. The manufacturer shall establish and maintain an

ESD control program in accordance with MIL-STD-1686. The manufacturer should establish and maintain an ESD

control program in accordance with and MIL-HDBK-263. Evidence of such compliance shall be verified by the

qualifying activity of this specification as a prerequisite for qualification and continued qualification. As a minimum,

this system must address the identification of ESDS sub-components and end items, facilities, training, design

protection, handling procedures, marking, cleaning, preservation, packaging, and quality assurance. A model ESD

control program is available from the qualifying activity and may be used as a guideline document.

4.3 Inspection conditions. Unless otherwise specified herein, the test conditions specified in the "GENERAL

REQUIREMENTS" of MIL-STD-202 shall be considered for reference purposes only. All inspections may be

performed at ambient conditions consistent with industry practice.