Abstract: A bootstrap logic driver circuit operable from a low voltage power supply includes first and second bipolar transistors coupled between positive and negative voltage supplies and having a collector load comprising a first diode structure. A further transistor coupled between the voltage supplies has a collector load comprising a second diode structure. A bootstrap capacitor coupled between the diode structures stores charge when the circuit is in a first condition and is discharged when the circuit is in a second condition to provide an enhanced drive voltage for an output transistor.

Abstract: A method and apparatus for detecting an aberrational stitch, normally a skipped stitch, in real time in a sewing apparatus. Movement of thread is detected, and a signal is generated if the thread is moving. At the same time, revolution of the handwheel of the sewing machine is detected, and pulses representative of the revolution are generated. The pulses are accumulated so long as the thread is moving, and the accumulated pulses are compared with a minimum number of pulses for a period of time. After one revolution of the sewing machine handwheel, representative of one stitch, the results of the comparisons are used to determine an aberrational stitch, and if a malformed stitch is detected., the sewing apparatus is stopped.