Testing

Released in May of 2011, GR-1089-CORE Issue 6 Electromagnetic Compatibility (EMC) and Electrical Safety requirements for Network Telecommunications Equipment has undergone a number of technical changes. We look at its substantial modifications and the potential impact on previously certified products.

Telecommunication equipment is being widely used in everyday life. The undesired electromagnetic noise emissions from this equipment could interfere with the signals in other communication equipment in the vicinity. When the noise is in the audio range of 25 Hz to 20 kHz, it may also affect the quality of signal transmissions in telephone lines. In audio systems, this undesired audible noise can be in the form of hissing, humming and other sound disturbances.

In order to ensure that a battery-driven product functions properly, there are different methods of testing and evaluating the battery’s functioning and safety. There are four different categories of tests that can be used in order to qualify a battery.

Today’s end-use electronic equipment has a number of characteristics that require protection from the electromagnetic environment. These characteristics include the growing use of digital electronics (still with a layer of analog electronics); multiple inputs and outputs for power, data, controls and indicators; ventilation for air flow and thermal management; and small openings for accessories. Few pieces of equipment use only one microprocessor. Multiple digital packages (i.e., integrated circuits) are used for small and large amounts of memory, signal processing, and input/output control just to name a few. The days of having just one power cord and a few knobs for control have long since past.

Injection of audio frequency ripple on equipment input power conductors has a long history, going back to 1953 (MIL‑I‑6181B) in the United States military, and at least as far back as 1961 in commercial aviation (RTCA/DO‑108). Audio frequency injection has been accomplished by inserting the secondary windings of a coupling (isolation) transformer in series with the power conductor to the test sample. While various transformers had been used prior to the 1960s, one has become standard since 1963. That Model is the Solar Electronics Model 6220, designed in 1962 and accepted by the United States Air Force in 1963 as being superior to previously used injection transformers. [1]