An electrosurgical generator configured to generate at least one electrosurgical waveform, comprising a closed loop control system for controlling the at least one electrosurgical coagulation waveform, the closed loop control system including: a sensor configured to sense at least one of a tissue property and an energy property and transmit the at least one of a tissue property and an energy property to a gain controller as a voltage or current sensor signal having an amplitude; characterized by: the gain controller configured to process the sensor signal to reduce the amplitude of the sensor signal and to obtain a signal to noise ratio within a predetermined range, the gain controller comprising: a sensor scaler control configured to scale the amplitude of the sensor signal and to generate a scaled sensor signal; a gain control configured to process a variable DC level control signal to generate a gain control signal; a multiplier coupled to the sensor scaler and the gain control, the multiplier configured to multiply in real-time the scaled sensor signal and the gain control signal to normalize the sensor signal independent of the amplitude thereof; and a microprocessor coupled to the electrosurgical generator configured to adjust the at least one electrosurgical coagulation waveform as a function of the sensor signal. a sensor configured to sense at least one of a tissue property and an energy property and transmit the at least one of a tissue property and an energy property to a gain controller as a voltage or current sensor signal having an amplitude; characterized by: the gain controller configured to process the sensor signal to reduce the amplitude of the sensor signal and to obtain a signal to noise ratio within a predetermined range, the gain controller comprising: a sensor scaler control configured to scale the amplitude of the sensor signal and to generate a scaled sensor signal; a gain control configured to process a variable DC level control signal to generate a gain control signal; a multiplier coupled to the sensor scaler and the gain control, the multiplier configured to multiply in real-time the scaled sensor signal and the gain control signal to normalize the sensor signal independent of the amplitude thereof; and a microprocessor coupled to the electrosurgical generator configured to adjust the at least one electrosurgical coagulation waveform as a function of the sensor signal. the gain controller configured to process the sensor signal to reduce the amplitude of the sensor signal and to obtain a signal to noise ratio within a predetermined range, the gain controller comprising: a sensor scaler control configured to scale the amplitude of the sensor signal and to generate a scaled sensor signal; a gain control configured to process a variable DC level control signal to generate a gain control signal; a multiplier coupled to the sensor scaler and the gain control, the multiplier configured to multiply in real-time the scaled sensor signal and the gain control signal to normalize the sensor signal independent of the amplitude thereof; and a microprocessor coupled to the electrosurgical generator configured to adjust the at least one electrosurgical coagulation waveform as a function of the sensor signal. a sensor scaler control configured to scale the amplitude of the sensor signal and to generate a scaled sensor signal; a gain control configured to process a variable DC level control signal to generate a gain control signal; a multiplier coupled to the sensor scaler and the gain control, the multiplier configured to multiply in real-time the scaled sensor signal and the gain control signal to normalize the sensor signal independent of the amplitude thereof; and a microprocessor coupled to the electrosurgical generator configured to adjust the at least one electrosurgical coagulation waveform as a function of the sensor signal.