Reed Relays and
Electronics India Limited
Manufacturer of Reed Switches, Reed Sensors and Reed-based products
Reed Relays and Electronics India Limited Incorporated in 1971

Crash Sensors use Reed Switches for Deploying Airbags

Crash Sensors trigger airbags
Airbags triggered by Crash Sensors

Statistics say almost 80% of automobiles use reed switch based crash sensors or safing sensors for deploying airbags. Luxury cars trigger airbags after sensing which passenger seats are being used and Reed Sensors are also used as seat sensors in certain high end models.

On impact, the crash sensor is activated in less the 2 milli-seconds and this immediately triggers the gas canisters that fill the airbags. Special high performance and high speed reed switches with a guranteed operate time of less than 2 milli seconds are used to manufacture crash sensors.

Crash sensors consists of ring magnet is mounted on a very precise tension spring and this assembly is slid over a reed switch. Depending on the impact which is required to trigger the reed switch, different tension springs are used. In most crash sensors, two reed switches are used instead of one as a failsafe mechanism. When a crash occurs, the mass of the magnet compresses the spring and moves closer to the reed switch, closing it. This signal is used to trigger the compressed cylinder which inflates the airbags.

Application Classification

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.

Position sensing Type
Position sensing Position Sensing type application When an application requires the end position of a movement sensed, or the sensing of a part when it Continue reading ->

Feb 28, 2024

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.

R3 Miniature SMD Reed Sensor
Miniature Reed Sensor These miniature SMD reed sensors are designed for low power, high speed switching applications, and have a cost advantage over the Continue reading ->

Jun 7, 2021

R2 Standard size SMD Reed Sensor
Standard Size Reed Sensor R2-S Gull-wing SMD Formed Reed SensorR2-S Gull-wing SMD Formed Reed Sensor Pad LayoutR2-F Low Profile SMD Formed Reed SensorR2-F Low Continue reading ->

Dec 2, 2020

MM-1018 Micro Miniature Reed Switch
Micro Miniature Reed Switch Size This 10.0 mm long, Form A type Micro Miniature reed switch is designed for moderate power, low load applications. The fast operate Continue reading ->

Nov 8, 2022

RM-1318 Reduced Miniature Reed Switch
Reduced Miniature Reed Switch Size The RM-1318 Reduced Miniature reed switches are designed for applications where a size restriction is present, but a higher Contact Continue reading ->

Nov 8, 2022