Abstract: An automatic power control system provides a control signal that regulates the output power of at least one laser diode. Coarse adjustment of the control signal is provided by a first means, preferably a digital variable resistor, while fine adjustment and compensation is provided by a second means, preferably by a digital-to-analog converter that receives an input signal proportional to a sensed control system parameter. The control system includes an operational amplifier having a first input coupled to sense output power, and a second input coupled to a DAC to provide finer resolution control. Memory can store system parameter or system parameter variations that can be coupled to the DAC and/or variable resistor to enhance system stability over ambient variations.

Abstract: An accelerator circuit is incorporated in a laser diode system for accelerating the turn-on operation of the laser diode independent of the control loop bandwidth of the laser diode system. The accelerator circuit provides a boost current to a compensation capacitor upon laser turn-on which compensation capacitor operates to establish the control loop bandwidth of the laser diode system. The boost current enables the control loop to increase the bias current to the laser diode quickly. When the laser diode reaches the desired operating point, the boost current is terminated and the control loop of the laser diode system resumes normal control of the bias current. In one embodiment, the accelerator circuit includes a timer circuit controlling a current source to implement open loop turn-on control. In another embodiment, the accelerator circuit includes a comparator circuit working in conjunction with an one-shot logic circuit for providing close loop control.

Abstract: An accelerator circuit is incorporated in a laser diode system for accelerating the turn-on operation of the laser diode independent of the control loop bandwidth of the laser diode system. The accelerator circuit provides a boost current to a compensation capacitor upon laser turn-on which compensation capacitor operates to establish the control loop bandwidth of the laser diode system. The boost current enables the control loop to increase the bias current to the laser diode quickly. When the laser diode reaches the desired operating point, the boost current is terminated and the control loop of the laser diode system resumes normal control of the bias current. In one embodiment, the accelerator circuit includes a timer circuit controlling a current source to implement open loop turn-on control. In another embodiment, the accelerator circuit includes a comparator circuit working in conjunction with an one-shot logic circuit for providing close loop control.

Abstract: A device for performing numerical value conversion of a digital input value in a first unit to a second, natural unit where the digital input value is a digitized value of a first measurement parameter includes a look-up table storing an array of coefficients for performing the numerical value conversion for multiple measurement parameters. The look-up table is indexed using a first parameter indicative of the first measurement parameter to provide a selected coefficient. The device further includes an arithmetic logic unit (ALU) receiving the digital input value and the selected coefficient and performing the numerical value conversion based on a first equation and the selected coefficient to compute a digital output value. The device also includes a saturation-limit circuit coupled to receive the digital output value from the arithmetic logic unit and provide a predetermined output value when the digital output value exceeds a predetermined maximum value.

Abstract: A device for performing numerical value conversion of a digital input value in a first unit to a second unit being a natural unit includes a look-up table storing an array of coefficients for performing the numerical value conversion. The look-up table is indexed using a first parameter to provide a selected coefficient. An arithmetic logic unit (ALU) is coupled to receive the digital input value and the selected coefficient and perform the numerical value conversion based on a first equation using the selected coefficient to compute a digital output value in the second unit. The first unit can be an arbitrary ADC unit and the second unit is a natural unit of physical measurement, such as volts, amperes, degree Centigrade. Furthermore, the device can be used to perform numerical value conversion from the arbitrary unit to the natural unit having a linear or a non-linear relationship.

Abstract: A dross processing system has a motor mounted to a motor support arm by a motor support carriage, and has a carriage guide which engages the motor support carriage to guide the motor along a vertical path between a raised position and a lowered position. The motor is moved by a motor height actuator connected between the motor support arm and the motor support carriage. A hood having a hood rim and a hood upper structure is configured to be engaged by the motor support carriage when moved to the raised position. When the motor is moved to the lowered position, the hood rim engages a reaction vessel upper rim. The motor support arm can rotate between a loading/dumping position and an operating position. The dross processing system can be partially automated by a microprocessor. A preferred impeller for agitating dross and a plug setting tool can be employed.