Claims
- 1. A drive device for a vehicle occupant protecting device comprising:
- an auxiliary power source which is charged by a DC power source;
- an igniting device;
- a switching element connected between a point connecting the DC power source with said auxiliary power source and said igniting device; and
- a control circuit for judging a magnitude of a collision based on an acceleration signal supplied from an acceleration sensor to provide a trigger signal to said switching element thereby electrically connecting said auxiliary power source to said ignition device when it is judged that an accident has occurred, said control circuit detecting an output voltage of said auxiliary power source.
- wherein said control circuit comprising a pulse-width varying circuit for varying a pulse width of the trigger signal in inverse proportion to the output voltage,
- and wherein a predetermined energy necessary to fire said ignition device is determined by said output voltage and said pulse width, and said control circuit varies said pulse width to deliver said predetermined energy to said ignition device.
- 2. The drive device according to claim 1, wherein said control circuit monitors said output voltage at discrete intervals of time, and accumulates sampled values, said control signal being terminated when said accumulated sample values correspond to said predetermined energy.
- 3. The drive device according to claim 1, wherein said control circuit comprises an integrator for integrating said output voltage of said auxiliary power source, wherein said control signal is terminated when an output value of said integrator reaches a value corresponding to said predetermined energy.
- 4. The drive device according to claim 1, wherein said control circuit comprises a microcomputer for digitizing said output voltage of said auxiliary power source for a preset period of time to thereby generate digital signals which are accumulated, wherein said control signal is terminated when an accumulated value of said digital signals reaches a value corresponding to said predetermined energy.
Parent Case Info
This is a divisional of application Ser. No. 08/063,752, filed May 20, 1993 now U.S. Pat. No. 5,506,775.
US Referenced Citations (29)
Divisions (1)
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Number |
Date |
Country |
Parent |
63752 |
May 1993 |
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