One of the DC motor armature starting debugging circuits with resistors in series

The circuit is shown in Figure 3-190. In this circuit, two-stage starting resistors Ri and Rz are connected in series to the armature circuit,
and the starting, speed regulation and shutdown control are realized through the master switch SA. During the starting process, the two time relays KTi and KTz automatically cut off the two
stages of starting resistance. The circuit is equipped with overcurrent protection (KIl) and weak magnetic protection (KI2). KA is the intermediate relay, and KA' is
the undervoltage relay.
    When starting, move SA from the "0" position to the "1" position, and the starting resistors Ri and Rz are both connected to the armature circuit. After
a delay (determined by KTi), Ri is short-circuited, and after a delay ( Determined by KT2), ​​and shorted Rz, the motor
enters normal operation at full voltage, and the starting process ends.
    If speed reduction is required, the main switch SA can be placed in the "2" or "3" position, and the motor will run with one or
two levels of resistance connected in series to the armature .