[Code of Federal Regulations]

[Title 47, Volume 1]

[Revised as of October 1, 2005]

From the U.S. Government Printing Office via GPO Access

[CITE: 47CFR15.32]



[Page 772-773]

 

                       TITLE 47--TELECOMMUNICATION

 

              CHAPTER I--FEDERAL COMMUNICATIONS COMMISSION

 

PART 15_RADIO FREQUENCY DEVICES--Table of Contents

 

                            Subpart A_General

 

Sec. 15.32  Test procedures for CPU boards and computer power supplies.



    Power supplies and CPU boards used with personal computers and for 

which separate authorizations are required to be obtained shall be 

tested as follows:

    (a) CPU boards shall be tested as follows:

    (1) Testing for radiated emissions shall be performed with the CPU 

board installed in a typical enclosure but with the enclosure's cover 

removed so that the internal circuitry is exposed at the top and on at 

least two sides. Additional components, including a power supply, 

peripheral devices, and subassemblies, shall be added, as needed, to 

result in a complete personal computer system. If the oscillator and the 

microprocessor circuits are contained on separate circuit boards, both 

boards, typical of the combination that would normally be employed, must 

be used in the test. Testing shall be in accordance with the procedures 

specified in Sec. 15.31.

    (i) Under these test conditions, the system under test shall not 

exceed the radiated emission limits specified in Sec. 15.109 by more 

than 6 dB. Emissions greater than 6 dB that can be identified and 

documented to originate from a component(s) other than the CPU board 

being tested, may be dismissed.

    (ii) Unless the test in paragraph (a)(1)(i) of this section 

demonstrates compliance with the limits in Sec. 15.109, a second test 

shall be performed using the same configuration described above but with 

the cover installed on the enclosure. Testing shall be in accordance



[[Page 773]]



with the procedures specified in Sec. 15.31. Under these test 

conditions, the system under test shall not exceed the radiated emission 

limits specified in Sec. 15.109.

    (2) In lieu of the procedure in (a)(1) of this section, CPU boards 

may be tested to demonstrate compliance with the limits in Sec. 15.109 

using a specified enclosure with the cover installed. Testing for 

radiated emissions shall be performed with the CPU board installed in a 

typical system configuration. Additional components, including a power 

supply, peripheral devices, and subassemblies, shall be added, as 

needed, to result in a complete personal computer system. If the 

oscillator and the microprocessor circuits are contained on separate 

circuit boards, both boards, typical of the combination that would 

normally be employed, must be used in the test. Testing shall be in 

accordance with the procedures specified in Sec. 15.31. Under this 

procedure, CPU boards that comply with the limits in Sec. 15.109 must 

be marketed together with the specific enclosure used for the test.

    (3) The test demonstrating compliance with the AC power line 

conducted limits specified in Sec. 15.107 shall be performed in 

accordance with the procedures specified in Sec. 15.31 using a 

enclosure, peripherals, power supply and subassemblies that are typical 

of the type with which the CPU board under test would normally be 

employed.

    (b) The power supply shall be tested installed in an enclosure that 

is typical of the type within which it would normally be installed. 

Additional components, including peripheral devices, a CPU board, and 

subassemblies, shall be added, as needed, to result in a complete 

personal computer system. Testing shall be in accordance with the 

procedures specified in Sec. 15.31 and must demonstrate compliance with 

all of the standards contained in this part.



[61 FR 31048, June 19, 1996, as amended at 62 FR 41881, Aug. 4, 1997]