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:
Mar. 11, 1986
Filed:
Feb. 29, 1984
Michael R Manes, Littleton, CO (US);
Aspen Laboratories, Inc., Englewood, CO (US);
Abstract
An electrosurgical unit having feedforward power regulation. In one embodiment there is an amplifier which produces a pulse modulated electrosurgical output signal. A microprocessor calculates an adjusted pulse width (duty cycle) just sufficient to account for the power changes due to voltage fluctuations. The microprocessor controls the pulse width of the gate voltage of a power transistor in the amplifier to regulate the amplifier output. In another embodiment the supply voltage is fed into the base drive circuitry of an amplifier power transistor through the photo-resistor side of an optoisolator. The lamp brightness of the optoisolator and thus the gain of the base drive circuitry is adjusted by the amplifier power level control. The nonlinearity of the optoisolator complements the nonlinearity of the amplifier so that the net gain in the amplifier drive at any power setting is just sufficient to account for the voltage fluctuation.