Speed control system for a corrugator

Abstract

The separate motors of the single facer and double facer machines of a corrugator are controlled in response to separate digital set point signals. Each set point signal is generated by a counter in response to a pulse generator. In a RUN mode, the counter automatically generates a preselected set point signal indicative of a preselected minimum speed and the motor speed is brought up to the preselected minimum speed. The pulse generator and counter are free-running until a digital detector senses the preselected set point signal and inhibits the pulse generator. In FAST and SLOW modes, the pulse generator is selectively steered by the operator to cause the counter to generate selective set point signals indicative of selective set point speeds and the motor speed is varied to the set point speeds. In SET, SPLICE HOLD and SLOW HOLD modes, the set point signal is automatically varied to indicate either an adjustable reference speed set by thumb wheel switches or preset reference speeds set by internal preset switches. The motor speed is varied to the appropriate reference speed. In these modes, the pulse generator is steered by a digital comparator which inhibits the pulse generator when the set point signal indicates either the adjustable or preset reference speeds. At the initiation of the SPLICE HOLD and SLOW HOLD modes, a temporary storage circuit stores the value of the set point signal. In a RESUME mode, the stored signal is transmitted to the digital comparator and the motor speed is restored to the stored value. In a SYNC mode, the single facer motor is controlled in synchronism with the double facer motor.