Equipment for the electronic speed control of an induction type motor, especially for use with data store motors

摘要

Equipment for the electronic speed control of an induction-type motor such as the drive motor for a tape recorder, comprises a tachogenerator fixed to the shaft of the motor and operating a pulse generator that has two outputs. A saw-tooth generator has two inputs and one output, one of the inputs of the saw-tooth generator being a start input and the other being a control input. The start input is coupled to the pulse generator, as is also the control input. The latter output of the pulse generator is connected to the control input of the saw-tooth generator and also to the control input of at least one sampling stage. The output of the saw-tooth generator is connected to a dc amplifier, which is in turn connected to the signal input of the sampling stage. The output of the sampling stage is connected to a grounded capacitor and also the the control input of the driver stage. A frequency pulse comparator receives signals from a velocity transmitter that senses the velocity of a portion of the equipment, and compares these signals with a reference frequency to transmit an error signal to the dc amplifier.