This paper is intended to explain the basic ideas related to designing digital algorithms using unmeasured mechanical variables (but observed without sensors), to control electromechanical systems digitally. The main idea is to simplify algorithms by using a linear discrete-time model without any variable limitations. Original references limiter based on the digital sliding mode for the exception of the variable limitations influences is proposed and designed. The simulation confirmed high dynamic accuracy, simplification of the digital control algorithm, and reduction of the computing capacity requirements of the controller.