Abstract: A doll simulating infant behavior includes sensors that detect care given to the doll, such as feeding, rocking, and neglect or abuse, and provide inputs to a microcontroller which operates on a behavioral state machine to produce infant behaviors that are expected of a human infant in response to similar care. The doll includes a head portion having an opening for a mouth having sensors in communication with a programmable microcontroller. The sensors include a feed-switch, motion sensors, and an impact sensor. LED eyes, a speaker, and a bi-colored blinking LED provide the doll's heartbeat and overall health. The microcontroller is programmed to receive inputs from the plurality of sensors and the feed-switch, and causes the doll to undergo a plurality of behavioral cycles such as sleeping, hunger, feeding, crying, wailing, colic and burping.

Abstract: A high frequency, high voltage starting circuit for a plasma arc cutting torch is operated in pulses to restart the torch if an initial arc extinguishes before the arc transfers to the workpiece. The starting circuit includes a D.C. power supply with its negative output connected to an electrode of the torch. A positive output is connected to a nozzle, and at a higher positive voltage, to a workpiece. A surge injector circuit of a resistor and surge capacitor is connected in parallel with the power supply to supply current to the arc as soon as breakdown occurs. The duration of the interval between restart pulses is sufficient to allow the surge injector circuit to recharge to a value that will reliably restart the arc as the power supply ramps up to a steady state pilot arc current.

Abstract: The positioning method disclosed herein is particularly applicable to a plasma arc cutting torch of the type in which tangential swirl is imparted to an ionizable gas through which the arc discharge takes place. The gas flow is initiated while the torch is in a retracted position and the torch is then advanced toward the workpiece. The vortex pressure is sensed and a signal is generated which is responsive to changes in vortex pressure. The advance of the torch is terminated in response to a change in the signal corresponding to the abrupt drop in the vortex pressure caused by attachment of the vortex to the workpiece.