Circuit for supervising contact for passenger protective device

• US 4,701,628 A
• Filed: 12/01/1986
• Issued: 10/20/1987
• Est. Priority Date: 11/30/1985
• Status: Expired due to Fees

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company), NEC Home Electronics, Ltd. (NEC Corporation)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company), NEC Home Electronics, Ltd. (NEC Corporation)
• Inventors: Kamiji, Koichi, Kumasaka, Toru, Ohya, Toshikazu
• Primary Examiner(s): Shoop, Jr., William M.
• Assistant Examiner(s): IP, SHIK LUEN PAUL
• Application Number:
  US06/936,358
• Time in Patent Office: 323 Days
• Field of Search: 307/9, 307/10 R, 307/10 SB, 340/52 R, 340/52 E, 340/52 D, 340/52 F, 340/52 H, 340/53, 340/64, 340/77, 280/727, 280/728, 280/734, 280/735, 280/736, 280/737, 280/739, 280/748, 280/741, 280/742, 280/802, 180/268, 180/270, 180/283, 180/271, 180/272, 180/273, 180/274, 180/281, 180/282
• US Class Current: 340/438
• CPC Class Codes: B60R 21/0176 for firing circuits using only mechanical switches as collision detecting means, in series with pyrotechnic fuses
• CPC Class Codes: G01R 31/006 on road vehicles, e.g. automobiles or trucks testing of ignition installations peculiar to internal combustion engines F02P17/00

Abstract

A contact supervising circuit for a rider protective device, in which an ignition switch, a collision sensor, and a detonator are connected in series to a DC power source, a monitoring resistor is connected in parallel to the collision sensor, and a monitoring switch is connected in series to the monitoring resistor. The device comprises delay means for closing a contact of the monitoring switch with a period of delay to interrupt a monitoring current flowing from the DC power source through the monitoring resistor for a predetermined period of time after turning-on of the ignition switch. The device further comprises assertion means for supervising the monitoring current and for asserting the fact that the monitoring current does not flow during the period of delay in which the closing the contact of the monitoring switch is delayed by the delay means.

Claims

1. A circuit for supervising contact for passenger protective device in which an ignition switch, at least one collision sensor, and a detonator are connected in series to a DC power source, comprising:

at least one monitoring resistor connected in parallel to said collision sensor;

at least one monitoring switch connected in series to said monitoring resistor;

means for closing a contact of said monitoring switch with a predetermined period of delay after turning-on of said ignition switch; and

means for asserting the fact that a monitoring current flowing from the DC power source through said monitoring resistor does not flow during said predetermined period of delay.

2. A circuit of claim 1, further comprising a fault detecting circuit connected in parallel to said detonator, the output of said fault detecting circuit being connected to said asserting means.

3. A circuit of claim 1, wherein said asserting means comprises an assertion lamp.

4. A circuit of claim 1, wherein said asserting means comprises at least one Schmitt trigger circuit connected to said ignition switch.

5. A circuit of claim 4, wherein said asserting means comprises a binary digital element connected to the output of said Schmitt trigger circuit.

6. A circuit of claim 5, wherein said delay means comprises a binary digital element connected to the output of said Schmitt trigger circuit.