Solid state power failure squib ignition control
AssigneeThe United States of America as represented by the Secretary of the Navy
InventorJeffrey L. Coleman
Life of this patent
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Abstract
A torpedo ejects lead weight at the conclusion of a practice run and is bed to the surface for recovery and reuse. A squib is initiated to release the weight by a control circuit which is actuated when the torpedo engine stops. An appropriately interconnected transistor and field effect transistor respond to built-up charges on three charge storage circuits to assure the proper initiation of the squib when the torpedo stops running. The stored energy thus is brought into effect to assure reliable separation and avoids the problems otherwise associated with conventional electromechanical relays.
Claims6
A control circuit for initiating a squib that releases a weight when a propulsion motor in a torpedo stops comprising:
- a power source coupled to the propulsion motor to provide DC power only when the propulsion motor is on;
- a first charge storage circuit coupled to said power source to store an initiating charge;
- a field effect transistor, coupled to be normally off having its drain electrode connected to said first charge storage circuit and its source electrode coupled to said squib;
- a second charge storage circuit coupled to the power source to provide a predetermined charge for a bias potential;
- a transistor having its base electrode coupled to the said second charge storage circuit and its collection electrode coupled to the gate electrode of said field effect transistor, the bias potential keeps the transistor off and consequently said field effect transistor is normally off;
- a third charge storage circuit coupled to said power source to store an actuating charge and being coupled to the emitter electrode of said transistor;
- and
- a feedback loop interconnecting the source electrode of said field effect transistor and said emitter electrode of said transistor, when said propulsion motor stops, said DC power stops causing said transistor to conduct and consequently turn said field effect transistor on to feed said initiating charge to said squib to insure the initiation thereof and to release the weight.
Dependencies are inferred from the claim text.