Current source for a supplemental inflatable restraint system

• US 5,309,030 A
• Filed: 10/19/1992
• Issued: 05/03/1994
• Est. Priority Date: 10/19/1992
• Status: Expired due to Term

• Current Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Original Assignee: Delco Electronics Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Schultz, Frederich H.
• Primary Examiner(s): Pellinen, A. D.
• Assistant Examiner(s): GANJIAN, PETER
• Application Number:
  US07/963,182
• Time in Patent Office: 561 Days
• Field of Search: 307/10.1, 280/735, 180/274, 180/282, 340/436
• US Class Current: 307/10.1
• CPC Class Codes: B60R 21/017 including arrangements for providing electric power to safety arrangements or their actuating means, e.g. to pyrotechnic fuses or electro-mechanic valves
• CPC Class Codes: H02J 9/061 for DC powered loads

Abstract

A supplemental inflatable restraint system with a controllable current source comprises a sense element, a switch device coupled to the sense element, and a squib coupled to the switch device, wherein the sense element, switch device and squib are coupled in a series circuit between a power source and a ground. A deploy control circuit is coupled to the switch device, and, in response to a deploy command, forward biases the switch device allowing electric current to flow through the sense element, switch device and squib to deploy a supplemental inflatable restraint. A current control circuit is coupled to the sense element and switch device and responds to the current flow through the sense element and regulates the switch device, effectively limiting current through the series circuit to a predetermined value.

Claims

1. Deployment apparatus for a supplemental inflatable restraint, comprising:

a sense element;

a switch device coupled to the sense element;

a squib coupled to the switch device, wherein the sense element, switch device and squib are coupled in a series circuit between a power source and a ground.

a deploy control circuit coupled to the switch device for forward biasing the switch device in response to a deploy command, allowing an electric current to flow through the sense element, switch device and squib to deploy the supplemental inflatable restraint; and

a current control circuit, coupled to the sense element and switch device, which responds to said electric current in the sense element and regulates the switch device to limit said electric current to a predetermined value.

2. A controllable current source for a supplemental inflatable restraint system, comprising:

a current sensing resistor in series with a transistor;

a deploy control circuit coupled to a switch device, and comprising means, responsive to a deploy command, for forward biasing the switch device allowing an electric current to flow through the current sensing resistor and the transistor to deploy the supplemental inflatable restraint system; and

a current control circuit, responsive to the current sensing resistor and controllably coupled to the transistor, including means for regulating the transistor in response to said electric current in the current sensing resistor, effectively limiting said electric current to a predetermined value.

3. A method of supplying current for deployment of a supplemental inflatable restraint, comprising the steps of:

forward biasing a gating device in response to a deploy command to supply current flow through the gating device, which current activates a deployment initiator;

sensing said current flow; and

biasing off the gating device when the sensed current flow exceeds a predetermined threshold to effectively regulate said current flow.