The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 05, 1995
Filed:
Dec. 17, 1993
William D Fahey, Cupertino, CA (US);
Theodore J Netoff, Milpitas, CA (US);
Giang V Dao, San Pablo, CA (US);
Richard Saasta, Redwood City, CA (US);
Quantic Industries, Inc., San Carlos, CA (US);
Abstract
The invention relates to providing a reliable means for controlling a laser diode in an initiator for starting a pyrotechnic reaction in an ordnance. The circuit has an array of capacitors to tune the coupling of the input signal to provide for more efficient power transfer from an electrical energy system. The circuit contains a full wave rectifier to provide DC power to operate the circuit. The circuit also contains a two stage current amplifier that is controlled by a differential amplifier. The differential amplifier compares a voltage proportional to the current flowing through the controlled laser diode with a reference voltage. The differential amplifier controls the current amplifier to limit the current that can pass through the laser diode. The circuitry that provides the reference voltage has the ability to drive the reference voltage to zero when the input signal is removed or is too low to drive the circuit properly. This prohibits current spikes from developing in the laser diode when the circuit is shutting down. The reference voltage circuitry also turns the laser diode on relatively slowly to allow the current control circuitry to become stable. This prevents damaging current overshoots that otherwise could occur at the time the laser diode is turned on.