The TC-3A operates as a tension controller, and it also has a preset counter. The tension output can be preset to the counter's value and the TC-3A outputs voltage in proportion to the counting value so that it maintains continuous tension control between the empty bobbin tension and full bobbin tension.
In combination with a tension control device, i.e. powder clutch, you can keep continuous control of the tension in coiling and uncoiling, without the use of a dancer roller.
