Controlling Airbags with Solenoids

A manual reset latching solenoid was used to in order to control airbag inflation based on variables programmed into the system that determined the severity of the accident.

Customer Problem

Airbags have evolved from a single safety measure to intricate systems that use multiple sensors and sophisticated software algorithms. Modern airbag systems deploy based on a list of variables: is the seat occupied, how much does the person weigh, are they wearing a seat belt, how fast is the car traveling.

In order to further protect passengers from injury, manufacturers sought to control airbag inflation based on variables programmed into the system, which determined the severity of the accident.

The TLX Solution

A manual reset latching solenoid provided the best solution for this application. When the airbag did not need to be completely inflated, a short electrical pulse cancelled the permanent magnet holding the solenoid in position.

Once de-latched, the solenoid opened a pressure relief valve to vent excess gas not needed for airbag inflation, preventing additional injury to passengers. Since the solenoid needed to be manually reset, it would not return to the latched position accidentally during the accident.

Miniature Manual Reset Latching Solenoid

Specifications
Stroke
2.5 mm
Holding force
>28 N (>6.29 lbs)
Supply voltage
6-16 Vdc
Response time
>3 ms
Coil resistance at 20°C
16.5 Ω ± 10%
Spring load
5 N (1.124 lbs)
Current
.7 amps

All TLX components are customized to fit system requirements, meaning technical specifications are unique to each customer and design. Examples given on our website are for illustration purposes only.

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