Electronic Restoration >> Troubleshoot An Electronic Circuit Board

Optical fiber cable assemblies consist of a combination of two or more of the following parts: optical fiber, cable, connectors, and assemblies. In most cases optical fiber is not used without some type of interconnection. Some of the test methods presented here have been developed at the GSFC Code 562 Technology Validation Assurance (TVA) Laboratory for Photonics Troubleshoot An Electronic Circuit Board and are noted as such. 

The TVA has developed these methods over the past 8 years to address the specific needs of space flight projects at GSFC and to address the failure modes that are common Troubleshoot An Electronic Circuit Board to Commercial-Off-the-Shelf (COTS) optical fiber devices. A references column is provided in Table 4 to provide insight into known failure modes and the test methods used to characterize them. 

All references cited hereare available at http://nepp.nasa.gov/photonics web site. It is important to note Troubleshoot An Electronic Circuit Board that military products cannot in general be assumed to be qualifiedfor space flight. Military specifications are not typically written to accommodate spaceflight requirements. The choice of military qualified fiber components is also verylimited. 

Therefore most of the parts and assemblies used for space flight are COTS.Many of the listed tests are common to commercial and space applications and can beconducted economically only by the manufacturer. In those cases, Troubleshoot An Electronic Circuit Board the manufacturer'scertified results are acceptable. Tests that are critical to determining the suitability ofproduct for space flight are either verified independently or performed in addition tomanufacturers' tests.

Table 3 summarizes the tests to be performed on optical fiber, optical fiber cable, opticalfiber connectors, and optical fiber assemblies that include either optical fiber terminatedto connectors or optical cable terminated by connectors. For each test and part type, a symbol letter is used to designate the entity by which the test is to be conducted: themanufacturer, Troubleshoot An Electronic Circuit Board end user, or both. 

A key is included at the bottom of the table.The Fiber Optic Test Procedures (FOTP-XXX) listed in Table 4 correlate directly to theEIA/TIA 455-XXX series. EIA/TIA 455 has been replaced by FOTP for brevity.Although more tests are done, Troubleshoot An Electronic Circuit Board those specified here are performed typically by the vendor. The tests presented here are required by NASA projects for validation purposes on allgrade levels (i.e., levels 1, 2, and 3). 

There are no distinctions in the validation andqualification of fiber optic components at this time between the grade levels. Testing offiber optics for space flight applications should be determined from the application andreliability requirements of the project. It is the responsibility of the user to specify detailed test conditions and Troubleshoot An Electronic Circuit Board pass/fail criteria for each test. 

These values shall be based on the nearestequivalent military specifications, manufacturer's specification, or the application, Troubleshoot An Electronic Circuit Board whichever is most severe.2/ The group 1A samples shall be subdivided as specified in the table for groups 2 to 6, inclusive. These minimum sample sizes are needed for qualification: Level 1 to 12 fuses Level 2 to 8 fuses Level 3 to 4 fuses3/ 

External visual examination required after testing to verify no evidence of mechanical damage.4/ The power supply shall have Troubleshoot An Electronic Circuit Board an open-circuit voltage not less than the specified voltage rating of the fuse under test.5/ Fuses rated < +125 °C shall be tested to condition A.6/ Materials listed in NASA Reference Publication 1124 that meet TML and CVCM limits are acceptable for use without further testing.7/ 

Not applicable for SMT fuses.8/ Not applicable for SMT fuses utilizing thick or Troubleshoot An Electronic Circuit Board thin film technologies. Hollow SMT fuses constructed with wire-in-air technology shall be subjected to the group 4 inspections. Fuses are specified to interrupt within a maximum of 5 seconds when driven at 200% of their rated current for nominal ratings up to and including 10 amperes. 

A fuse with a nominal rating of 15 amperes is specified to interrupt within a maximum of 10 seconds when driven at 200% of its rated current.The power supply shall be capable of delivering appropriate levels of current to achieve short fusing times.2/ In a space environment, Troubleshoot An Electronic Circuit Board the possible escape of air from inside the fuses reduces the filament cooling mechanism (heat transfer by conduction). 

Thislowers the blow current rating and decreases current capacity with time, making it necessary to derate current ratings on fuses used in space applications.3/ Fuses rated at 1/2 ampere or below are especially affected by loss of air; thus, Troubleshoot An Electronic Circuit Board their derating factors are larger.4/ Current derating factors are based on data from fuses mounted on printed circuit boards and conformally coated. 

Other types of mountings require Troubleshoot An Electronic Circuit Board project office approval. It should be noted that the lifetime of the fuses is controlled by two factors: cold resistance of the fuse and the heat sinkingprovided by the installer. The thermal resistance of the fuse to the thermal ground is very important, as is the case with power transistors and power diodes mounted on circuit boards.5/ 

Recent studies have shown the occurrence of enduring arcs in fuses rated at 125 volts when the applied voltage is greater than 50 volts. Therefore, Troubleshoot An Electronic Circuit Board the voltages on these fuses should be derated to 50 volts or less.6/ Electrical transients produce thermal cycling and mechanical fatigue that could affect the life of the fuse. 

For each application, Troubleshoot An Electronic Circuit Board the capability of the fuse to withstand the expected pulse conditions should be established by considering the pulse cycle withstanding capability for nominal I2t (energy letthrough the fuse) specified by the manufacturer. Any test that has been performed during screening on the samples selected for qualification tests need not be repeated.2/ 

Generic data may be used in lieu of testing as long as the data meets the following requirements:i) It is obtained on parts built to S-311-P-079 specifications using the same materials and Troubleshoot An Electronic Circuit Board similar construction and design, andbuilt in the same facility as the flight parts.ii) The data is less than 2 years old relative to the lot date code of the flight parts.3/ Samples for Groups 2, 3, and 4 should be selected from parts that have passed Group 1 tests.

How To Keep Ground Squirrels From Burrowing Under

Open season for hunting crows shall be from October 15 through November 30 and January 14 through March 31 of each year. No bag or possession limit. Entire state open.  Pigeons. 100.2(1) Pigeon season. There is a continuous open season for the taking of pigeons except the season for taking pige  read more..

Black Water Carpet Cleaning

Wetlands provide significant ecosystem services that include floodwater storage, water quality improvement, and wildlife habitat. Under U.S. Farm Bill programs, an array of defined conservation practices may be installed to reduce agricultural impacts on environmental quality, Water Extraction Black Water Carpet Cleaning with so  read more..

Debris Removal

In this first step, a person needs to consider the likelihood of earthquake existence, extent of the earthquake, the likelihood of fire start after the earthquake and the extent of the ignited Smoke Damage Debris Removal. An earthquake is a natural danger and which might be examined by the statistics-based method.   read more..

Get Water Stains Out Of Carpet

If you were ordered to evacuate your home, you must check with the mayor's office, town supervisor or local codes enforcement official before returning to your home. Even if you evacuated voluntarily, you should call the town clerk or the building department to ask about the status of buildings in y  read more..

Hurricane Damage Causing Tree Removal

This office reported that its applicants had "passed every decision through layers of FEMA approvals" at the time the original disaster cleanup was under way, and it was only informed years later that certain vegetative debris removal was ineligible for reimbursement. Several applicants have [M  read more..

How To Disinfect After Sewer Problems In A Basemen

It will probably never happen at your home, but in case it does, it's important to have the facts in advance. Remember, if you experience a sewer line blockage, Sewage Cleanup How To Disinfect After Sewer Problems In A Basemen call us first. This could save the unnecessary expense of a plumber. IF AN OVERFLOW OCCURS 1. Discontinue inside water use.2  read more..

Snake Removal

There are many reasons that a snake would want to go into your basement safety, shelter, or to escape the heat. It's amazing how they can fit through the smallest cracks and the tiniest openings. However the Animal Damage Snake Removal happens you must act upon it quickly to keep any further infestations under contro  read more..

Use A Foundation Drainage System To Remove Radon G

Check the following to make sure that you have enclosed the necessary attachments to the Application forms you are submitting.For Residential Measurement and Mitigation Services Providers A copy of either your CBT or paper-and-pencil official exam results. (Do not submit your Radon Mitigation Use A Foundation Drainage System To Remove Radon G application until   read more..

How To Repair Smoke Damage From Fire

For the second time this month, Fire Damage How To Repair Smoke Damage From Fire another state joined the national movement to enhance public safety by mandating that all cigarettes sold in their state be "fire-safe.” Such cigarettes are less likely to ignite fires if dropped or carelessly discarded.

Tod  read more..

Vermiculite

(05/21/03) The federal government today launched a national consumer awareness campaign to provide homeowners with important information on vermiculite attic insulation which may contain Asbestos Abatement Vermiculite asbestos. 

This new campaign, coordinated by EPA and the Agency f  read more..