July 2012

Immunity from voltage sags is vital for reliable operation of our ever more sophisticated electronic controls and equipment. Every electrical product should be able to ride through typical voltage sags, but in many cases the first sag test occurs after equipment is installed and in operation. Select the appropriate sag immunity specification and equipment compliance testing, and you’ll be glad you did.

Global parts procurement presents challenges to any product designer. If a component is sourced from multiple suppliers, how do you keep track of these suppliers from initial design to production, especially in a global manufacturing environment where products are made in multiple locations? Do you really have the right manufacturing and process controls to manage such an environment? The unit submitted to a certified test facility had a specific supplier but is there assurance that other suppliers will perform the same during testing? If not watched carefully, these variables could wreak havoc with product certification and regulators worldwide.

Low power, license-exempt FM transmitters are used in vehicles to transmit a weak signal onto a vacant channel in the FM Broadcast Band (88-108 MHz) for the purpose of receiving Sirius-XM broadcasts on the vehicle’s FM Radio. The only method for determining compliance of these transmitters according to the FCC Rules and Regulations is to measure the field strength from the transmitter installed in three typical vehicles. This article describes an alternative method for determining compliance by measuring conducted RF power output and using a transfer function derived by measuring the radiated field strength from transmitters installed in a number of vehicles.

The machine model (MM) test, as a requirement for component electrostatic discharge (ESD) qualification, is being rapidly discontinued across the industry.