MIL-R-19309 Relay, Sensitive For Torpedo Mark 37 Mod 2This specification describes the requirements for the acquisition of a double-pole, double-throw, sensitive electromagnetic relay, Drawing 1521140. The coil is rated at one watt at a voltage of 31.6 V dc. The relay is used in the control of functional circuits which operate on a nominal dc voltage of 25 volts and dc current up to two amperes.

Pages 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10 - 11 - 12 - 13 - 14

MIL-R-193090

4.3.4 Test procedure.

4.3.4.1 0ielectric strength. Apply ac power source (see 4.3.3.1) across each of contact terminals 2, 3, 4, 6, 7, and

8 and the relay case for a period of one minute ± 5 seconds. Apply this power source across coil terminal 1 (or 5)

and each of contact terminals 4 and 8 for a like period (see 3.5.1).

4.3.4.2 Insulation resistance. With the relay deenergized, measure the insulation resistance between the following points, using the megohmmeter or bridge of 4.3.3.2 (see 3.5.2):

(a) Terminals 1, 2, 3, 6, and 7 and the relay case. (b) Terminals 2, 3. 6, and 7 and terminal 1 (or 5).

4.3.4.3 Contact resistance. With the relay deenergized, measure the resistance across contacts 3 and 4 and across contact 7 and 8, using the Kelvin bridge or equivalent. With the rated current of 2 amperes flowing through contacts 3 and 4 and through contacts 7 and 8, measure the resistance across each pair of contacts. With the relay coil energized to close contact 4 to contact 2 and contact 8 to contact 6, and with the rated current flowing through these contacts, measure the resistance across each pair of contacts. The contact resistance of the contacts shall be as specified in 3.5.3. Upon completion of the operating life test (see 4.4.6), the contact resistance measured as above shall be no more than double the value specified in 3.5.3.

4.3.4.4 Contact bounce. With oscillograph (see 4.3.3.4), test the relay to determine whether or not it exhibits any evidence of chatter or contact bounce (see 3.5.4).

4.3.4.5 Coil resistance. Measure the coil resistance of the relay by any suitable means. The coil resistance shall be within the limits specified when corrected to the temperature indicated (see 3.5.5).

4.3.4.6 Coil current. With the relay deenergized, check continuity between terminals 3 and 4 and between terminals 7 and 8, using the dc voltage source and voltmeter in 4.3.3.3. With the coil energized with a coil current of

6.3 mA, check continuity between terminals 2 and 4 and between terminals 6 and 8 (see 3.5.6).

4.3.4.6.1 Operate. With rated current flowing through the appropriate contact terminals, apply a nominal ten V dc, through the variable resistance of 4.3.3.3 at maximum value and the milliammeter, across coil terminals 1 and 5. Gradually reduce the resistance value and accurately determine the current value at which contacts 4 and 8 transfer from 3 to 2 and from 7 to 6 respectively. The current value at which transfer takes place shall not exceed that specified in 3.5.6.1.

4.3.4.6.2 Release. With the circuit arrangement of 4.3.4.6.1 and the relay coil energized with a current of 6.3 mA, gradually increase the resistance value and accurately determine the current value at which contacts 4 and 8 transfer to contacts 3 and 7 respectively. The current value at which transfer takes place shall be not less than that specified in 3.5.6.2.

4.3.4.7 Sensitivity. From the values determined in 4.3.4.5 and 4.3.4.6, compute the operating and releasing sensitivity of the relay (see 3.5.7).

4.3.4.8 Operating and releasing time. With the oscillograph and interrupter (or signal generator) of 4.3.3.4, test the relay for chatter and contact bounce and determine the operating and releasing time of the relay at a rate of six transfers per second. The relay shall meet the requirements specified in 3.5.4 and 3.5.8.

4.3.4.9 Visual and dimensional examinations. Each relay shall be examined to determine conformance with the requirements for workmanship and dimensions.

4.3.4.10 Packaging, packing, and marking. Packaging, packing, and marking shall comply with the requirements of Section 5.

4.4 Preproduction and periodic production inspection. The preproduction and periodic production samples, after satisfactorily passing the conformance inspection detailed in 4.3, shall be subjected to the following tests and examinations. Certified inspection data covering the results of preproduction and periodic production inspections shall be forwarded to the acquiring activity.