Abstract: A system for printing an image onto a target area of a moving substrate with an actuatable print head having an actuation delay time, the substrate movable at a variable speed to a print position relative to the print head. The system includes a trigger signal generator for generating a trigger signal when the target area of the substrate is a specified distance from the print position so selected that a time required to move the target area of the substrate the specified distance to the print position is not less than the actuation delay time of the print head. Encoder signals based on movement of the substrate decrement a reference count during a delay time to generate a delay count, wherein the delay time corresponds to the actuation delay time of the print head. The encoder signals decrement the delay count in response to the generation of a trigger signal, wherein a print signal is generated when the delay count is decremented to zero.

Abstract: A capacitance sensing circuit utilizes an operational amplifier connected in a comparator configuration. The capacitance to be measured is connected to one input of the operational amplifier and is also connected to the output of the operational amplifier through a resistor to form a free-running multivibrator. The period of the multivibrator output depends upon the value of capacitance being measured. A switching transistor is connected to the output of the operational amplifier to cause a changing current output signal. The output signal is obtained as a change of current in a current sensor connected to the collector of the transistor.