On some electronic flasher relays, particularly those used in automotive applications, “EF” often denotes “electronic flasher.” This marking differentiates it from thermal flasher units, which rely on a heating element and bimetallic strip to create the flashing effect. An electronic type uses solid-state circuitry to control the on/off cycling of the lights. For instance, an EF90 flasher relay would be an electronic unit designed to handle a specific load, typically indicated by the “90.”
The importance of understanding this designation lies in selecting the correct component for a vehicle’s lighting system. Electronic flashers offer several benefits over their thermal counterparts, including greater reliability, longer lifespan, and the ability to function properly with LED bulbs, which draw significantly less current. Historically, thermal flashers were the standard, but the increasing adoption of LED lighting has driven the transition towards electronic solutions.
