Motor Timing Control Circuit
Original Publication Date: 1983-Nov-01
Included in the Prior Art Database: 2005-Feb-07
This timing control circuit senses motor speed and corrects for changes in motor speed caused by transient shifts in the power line frequency servicing the motor. In one application example, the basic timing of a pulsed laser drill (not shown) is derived from a chopper disk (not shown) which is driven by a hysteresis synchronous motor (not shown). As a result, any transient shift in the line frequency causes a corresponding shift in the motor speed and consequently the timing signals. This circuit compensates for the shift in timing. The basic operation of the laser drill acoustic sensing is shown in the timing diagram of Fig. 1. The laser pulse control signal B produced by the chopper disk starts drilling a hole at the proper location on a workpiece, such as a printed circuit (PC) panel or the like (not shown).