Vehicle Power Door Locks Controlled Using A Reed Sensor REED RELAYS REED SENSORS REED SWITCHES Introduction Power door locks are now designed into 75% of all new cars, and 100% on all full feature models. The power door locks can be opened wirelessly or by placing in a code that is compared electronically to the preset code on the onboard computer. If they match the locks are disengaged. Engaging the lock can be done remotely or by lifting the handle of the car door handle. The Reed Sensor senses this motion and activates the locking motion. Reed Sensors have been an excellent choice carrying out this function in a reliable manner. 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 pick up the handle motion Figure 2. Illustration shows reed sensor in its normally open state. Car lock is unlocked and alarm not activated. • 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 handle rotation associated with power door locks • Ideal for applications sensing any kind of motion in a host of different configurations Figure 3. When driver lifts on door handle the reed contacts close sending a signal to the electronics to lock the door and activate the alarm system. Locking Power Door Can be Done Reliably Using Sensors Reed Locking car doors has been a fundamental part of vehicles for the last 100 years. Slowly power door locking was introduced and is now used in the majority of all automobiles. The locking can be done remotely or it can be done by lifting the door handle. Reed Sensors have been shown to be an excellent way of locking the door when the handle is lifted. A magnet is conveniently located in the moving mechanism of the handle. When this is moved the reed sensor activates sending a signal to the on-board computer in turn locking the door, turning on the interior lights briefly and energizing the alarm with a few short beeps. 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 Vehicle Power Door Locks Controlled Using A Reed Sensor REED RELAYS REED SENSORS REED SWITCHES Specifications Operate specs Min Max Units Must close distance 5 25 mm Must open distance 5 25 mm Hysteresis Load Characteristics Switching voltage 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 MK15 MK15 Typical 50% Min Max Units 200 0.5 1.5 10 150 200 320 -20 -35 -20 -35 0.5 0.1 85 85 130 130 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. Surface Mount Series V Amps Amps Watts mΩ Series mΩ MK16 V msec msec °C °C °C °C MK15 MK17 MK22 MK23MK23-35 MK23MK23-66 MK23MK23-87 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 Figure 3. MK15 Tape & Reel 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 Vehicle Power Door Locks Controlled Using A Reed Sensor 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