Method and device for operating a trigger device for occupant protection means

Patent metadata

Field	Value
Publication number	US-9539972-B2
Application number	US-201214365094-A
Country	US
Kind code	B2
Filing date	Dec 17, 2012
Priority date	Dec 20, 2011
Publication date	Jan 10, 2017
Grant date	Jan 10, 2017

Abstract

A method for operating a trigger device for an occupant protection unit includes: activating a first switch (high side) of the trigger device for occupant protection units; activating a second switch (low side) of the trigger device for occupant protection units; detecting an output voltage at the second switch (low side); and deactivating the second switch (low side) as a function of the output voltage.

First claim

What is claimed is:

1. A method for operating a trigger device for an occupant protection unit, comprising:
activating a first switch of the trigger device and a second switch of the trigger device for triggering purposes to connect at least one trigger element to a voltage supply;
detecting an output voltage at the second switch; and
deactivating the second switch as a function of the output voltage;
wherein the trigger device is configured to trigger activation of the occupant protection unit.

2. The method as recited in claim 1 , wherein the method is carried out after a short circuit to the supply voltage is detected.

3. The method as recited in claim 2 , wherein the trigger device for the occupant protection unit has an inductive trigger element.

4. The method as recited in claim 1 , wherein the second switch is deactivated after a predefined first time period if the output voltage remains above a predefined limiting value for the output voltage during the first time period.

5. The method as recited in claim 4 , wherein the second switch is deactivated after a predefined second time period if the output voltage drops below the predefined limiting value for the output voltage within the first time period.

6. The method as recited in claim 5 , wherein the predefined first time period is shorter than the predefined second time period by at least one power of ten.

7. A device for triggering an occupant protection unit, comprising:
a short-circuit detection unit for recognizing a short circuit to a supply voltage;
a first switch and a second switch provided for triggering the occupant protection unit; and
a voltage detection unit for detecting an output voltage at the second switch, wherein the second switch is deactivated as a function of the output voltage at the second switch;
wherein the device is configured to trigger activation of the occupant protection unit.

8. The device as recited in claim 7 , wherein the device includes at least one inductive trigger element.

9. The device as recited in claim 8 , wherein the short-circuit detection unit operates cyclically.

10. The device as recited in claim 8 , further comprising a clock for detecting time periods, wherein the second switch is deactivated after a predefined first time period if the output voltage remains above a predefined limiting value for the output voltage during the first time period.

11. The device as recited in claim 10 , wherein the second switch is deactivated after a predefined second time period if the output voltage drops below the predefined limiting value for the output voltage within the first time period, wherein the predefined first time period is shorter than the predefined second time period by at least one power of ten.

Assignees

• Bosch Gmbh Robert

Inventors

• Balz Stefan

Classifications

• B60R2021/01143

  Short circuits · CPC title

• B60R21/0173 Primary

  Diagnostic or recording means therefor · CPC title

• B60R21/017 Primary

  including arrangements for providing electric power to safety arrangements {or their actuating means, e.g. to pyrotechnic fuses or electro-mechanic valves} · CPC title

• B60R2021/01252

  Devices other than bags · CPC title