Electromechanical components perform system functions that are usually outside the range of electronics. Key products include relays, switches and fans. However, electronics even intrude into the operation of some of these products. For example, relays have solid-state versions creeping into higher current ranges. However, conventional mechanical relays are still used extensively for medium to heavy current loads in applications such as automobiles. For example, in the 30 to 60A range, electromechanical relays frequently control headlights, wipers, fans and more.
In addition to historically lower cost, relays avoid the cooling requirements that restrict power semiconductors in this current range. Raise the voltage from the traditional 14V to several hundred voltages for handling the high currents in hybrids, and relays don't have any competition from solid-state products
In the lower power range, pc board-mounted relays continue to evolve, taking less space on the board and even have surface mount technology (SMT) versions to simplify board assembly.
In this section, trends in both automotive relays and pc board relays are addressed.
That's a Switch
While continuously improving to achieve smaller and smaller form factors is common to integrated circuit (IC) technology and the electronic assemblies that use these ICs, switches can make similar claims.
Honeywell's 91MCE Series of miniature limit switches target the space restrictions in scissor and aerial lifts, machine equipment and material handling. These entirely different applications warrant a considerably larger "small switch." With a 20 mm mounting pattern that meets most globally accepted mounting standards, the switches have a 10A thermal rating and operate from voltages up to 300V ac and 250V dc.
Small is a switch trend specifically addressed in this section.
Really Not a Fan of
The cooling of electronic circuits and even building requires continually more efficient airflow. While new fans address this broad range of requirements, cooling is another area that electronics has started to penetrate with thermoelectric coolers.
In the cooler section, two traditional electromechanical fans and one thermoelectric cooler tackle application-specific requirements.