Reed switches in Defective lamp detection
Automobiles these days provide a wide range of information ranging from door and window position, wind screen viper fluid level, whether a tail lamp has failed, the positions of the engine hood and trunk and also whether the fuel cap has been closed fully. Reed sensors are the only devices that are hermetically sealed and completely safe to use even inside fuel tanks and they are molded, which means they can withstand higher shock and vibration limits, as well. Reed Sensors also have the added advantage of withstanding temperatures of up to 150°C without much change in actuating distance when the right magnets are used. Tail lamps and parking lamps are very vital elements of an automobile and any failure could cause accidents. Reed relays, by virtue of their small size and high life, find an important role in these applications. A reed relay and a resistor are connected across the lamp and when the lamp fuses, the reed relay energizes and the output is used to trigger an alarm on the dash board.
Applications are classified as Position Sensing, Pulse Counting, Electromagnetic or Relay, Temperature Sensing or Magnet Biasing types. This application is classified as follows and the link gives more information on best practices to help select the most suitable AT band and matching magnet.
The Reed Switches and Sensors used in such applications need to be robust, durable and efficient in meeting a high life expectancy. Our engineers work hard in life testing our products under various conditions, and our intention is to ensure end product durability and life. Although we wouldn’t want to restrict any of our products for use in only certain applications, the recommended products for use in this application are listed below.