Reed Sensor Detects Key In Ignition And Auto Lights Left On REED RELAYS REED SENSORS REED SWITCHES Introduction How often has one forgot and left the keys in the ignition and/or left the main head lights on, only to later return to the car and find the battery dead or the vehicle not even there. The Reed Sensors have come to the rescue. MEDER’s Reed Sensors have been chosen as an excellent choice in eliminating these possibilities from happening. Figure 1. MK17-X-3 Sensor physical layout Features • The reed sensors reliably operate between 50˚C to 150˚C • Magnet and Reed Sensor are isolated and have no physical contact by typically having the magnet mounted on the handle and the Reed Sensors mounted and positioned to accurately detect the handle motion Figure 2. Key is shown in the ignition. Reed switch is not activated unless the drivers door handle is pulled. • The reed switch used in the Reed Sensor is hermetically sealed and is therefore not sensitive to rough, wet environments • The magnet is not affected by its environment • Tens of millions of reliable operations • Surface mount and through hole packages available • Cylindrical hole and screw fastening mounting • Contacts dynamically tested Applications • Ideal for sensing the motion of a car door handles both internally and/or externally • Ideal for applications sensing any kind of motion in a host of different configurations Figure 3. Key is shown in the ignition and drivers door handle is pulled activated the reed switch to sound the alarm indicator. Locking Power Door Can be Done Reliably Using Sensors Reed All systems have their shortcomings and when it comes to automobiles a few are worth mentioning and focusing on: 1. the possibility of leaving one’s auto with the keys still in the ignition; and 2. is leaving the main head lights on. Obviously, the vehicle can be stolen in the former and the battery drains in the latter. Auto designers have taken different approaches to solve the problem but none have heretofore been the perfect approach. However, now MEDER’s engineers are working with auto designers and using MEDER’s reed sensors very successfully to solve these problems. Generally the last person out of the car and the one in control of the keys and light switch is the driver. So it makes sense to attack the problem from the driver’s position. And that is exactly what has happened. MEDER electronic Application MEDER electronic AG | Germany | tel.: +49(0)7731/8399-0 | Email: [email protected] MEDER electronic Inc. | USA | tel.: +1 508.295.0771 | Email: [email protected] Page 1 of 3 www.meder.com Reed Sensor Detects Key In Ignition And Auto Lights Left On REED RELAYS REED SENSORS REED SWITCHES Specifications Specifications Defining the MK06 & MK15 Series Operate specs Min Max Units Must close distance 5 25 mm Must open distance 5 25 mm Hysteresis Load Characteristics Switching voltage Switching Switching current Carry current Contact rating Static Contact resistance Dynamic contact resistance Breakdown voltage Operate time Release time Operate Temp MK06 Storage Temp MK06 Operate Temp MK15 Storage Temp Temp MK15 Typical 50% Min Max Units 200 0.5 1.5 10 150 200 320 -20 -20 -20 -20 0.5 0.1 85 85 130 130 V Amps Amps Watts mΩ mΩ V msec msec °C °C °C °C To exit the vehicle the driver must engage the door handle to leave the vehicle. In this case, the auto makers have cleverly designed a magnet into the handle. MEDER’s reed sensors are strategically placed internally in the door to sense this motion. When the reed sensor is activated, the on-board computer checks to see if the keys are still in the ignition and if the main lights are still on. If either are detected a beeping noise is sounded alerting the driver that something is amiss. This approach has already successfully kept many thousands of cars from being stolen and a corresponding number of batteries not to be drained unexpectedly. The reed sensor is a excellent choice because it can operate reliably from -50˚C to 150˚C and represents an economical way to carry out the sensing function. Because MEDER’s sensors use hermetically sealed reed switches that are further packaged in strong high strength plastic, they can be subject to rough treatment and environmental concerns such as dirt, grease, and moisture without any loss of reliability. MEDER’s sensors are packaged for surface mounting as well as through hole mounting. Also, MEDER has cylinder packages and well as screw fastening packages having lead wires for remote attachment to the electronics. Consider some of the below options in surface mount, through hole, cylindrical and rectangular versions for water flow sensors or similar applications. Surface Mount Series Series MK15 MK16 MK17 MK22 MK23MK23-35 MK23MK23-66 MK23MK23-87 Figure 3. MK15 Tape & Reel MK23MK23-90 Dimensions mm W 2.5 H 2.5 L 19.50 W 2.3 H 2.3 L 15.60 W 2.1 H 2.1 L 9.61 W 2.7 H 2.3 L 15.60 W 2.2 H 1.95 L 15.75 W 2.2 H 2.7 L 19.60 W 2.0 H 2.1 L 15.60 W 2.54 H 3.05 L 24.9 Illustration inches 0.098 0.098 0.768 0.091 0.091 0.614 0.083 0.083 0.378 1.060 0.091 0.614 0.087 0.077 0.620 0.087 1.060 0.772 0.079 0.083 0.614 0.100 0.120 0.980 MEDER electronic Application MEDER electronic AG | Germany | tel.: +49(0)7731/8399-0 | Email: [email protected] MEDER electronic Inc. | USA | tel.: +1 508.295.0771 | Email: [email protected] Page 2 of 3 www.meder.com Reed Sensor Detects Key In Ignition And Auto Lights Left On REED RELAYS REED SENSORS REED SWITCHES Through Hole Series Series MK06MK06-4 MK06MK06-5 MK06MK06-6 MK06MK06-7 Dimensions mm W 3.3 H 3.3 L 12.06 W 2.8 H 3.2 L 14.30 W 3.3 H 4.2 L 17.24 W 3.3 H 4.2 L 19.78 Illustration inches 0.130 0.130 0.475 0.110 0.126 0.563 0.130 0.165 0.679 0.130 0.165 0.779 Cylindrical Panel Mount Series Series MK03 MK03 Dimensions mm Dia 5.25 L 25.5 Illustration inches 0.207 1.004 MK14 MK14 Dia L 4 25.5 0.157 1.004 MK18 MK18 Dia L 5 17 0.197 0.669 MK20/1 MK20/1 Dia L 2.72 10 0.107 0.394 Rectangular Screw Flange Mount Series Series MK04 MK05 MK05 MK12 MK12 Dimensions mm W 13.9 H 5.9 L 23.0 W 19.6 H 6.1 L 23.2 W H L 14.9 6.9 32.0 Illustration inches 0.547 0.232 0.906 0.772 0.240 0.913 0.587 0.272 1.260 **Consult the factory for more options not listed above. ** MEDER electronic Application MEDER electronic AG | Germany | tel.: +49(0)7731/8399-0 | Email: [email protected] MEDER electronic Inc. | USA | tel.: +1 508.295.0771 | Email: [email protected] Page 3 of 3 www.meder.com