Modern development of power semiconductor technology makes it possible to obtain special characteristics of the asynchronous drive, to expand the area of its application. The simplest way to form the required characteristics is to regulate the parameters of the rotor and stator circuits of the induction motor by means of thyristors.For non-contact regulation of the rotor circuit resistance, the rotor circuit of the motor includes a rectifier assembled according to the Larionov scheme of uncontrolled semiconductor valves. A resistance R and a choke L are included in the DC circuit of the rectifier. The resistance can be shunted by thyristor T₁. A capacitance C is used to lock thyristor T₁, which is switched on by thyristor T₂. The auxiliary circuit of inductance L₁ and diode D₁ serves to recharge the capacitance in the process of switching thyristors.

In mine signaling, interlocking, automatic control schemes, the system of magnetic logic elements (MLE) produced by the Kalinin Electric Equipment Plant has found a fairly wide application. However, the existing output devices for this system have a number of fundamental disadvantages, limiting in some cases the use of magnetic logic elements in mines. In this connection it is especially important to create output devices using silicon controlled valves (SCV) ...