Pulse Control of Electric Drive

Pulse Control of Electric Drive


a method of controlling the speed of rotation or the torque of electric motors. It is based on a periodic change in the parameters of the motor circuits or of the circuit connecting the motor to the power supply. For example, if the contact of the pulse control element P is closed (see Figure 1), the circuit of the armature A is connected to the power supply Up, and the motor accelerates. If the contact is opened, the motor is braked by the static moment of the load Ms. The average speed of rotation n is determined by the relative time τ1 of connection of P and by the load Ms; that is, the speed of rotation can be regulated within wide limits by changing the pulse duration of the supply voltage. Relays, contactors, magnetic amplifiers, ion devices, and transistors may be used as switching pulse elements. Circuits of this type have low efficiency and a low usage factor for motors with wide regulation of the speed of rotation.

Figure 1. Pulse regulation of speed of rotation of an electric motor: a) connection diagram of motor and time diagram of its operation, (b)mechanical characteristics of the electric drive; (P) pulse control element, (A)armature of electric motor, (Up) electric power supply, (M8) load, (ua) armature voltage, (ia) armature current, (n)speed of rotation

Pulse control of electric drive is characterized by simplicity and reliability. Transistorized controls are also highly economical and of small size and weight. Therefore, such controls are widely used in aircraft electric drives and metalworking machinery.

Figure 1. Electric pulses: (a), (b), (c), (d) square, trapezoidal, exponential, and bell-shaped video pulses; (e) radio pulse


Tverdin, L.M. “Sistema URV-D s impul’snym regulirovaniem skorosti vrashcheniia.” In Avtomatizirovannyi elektroprivod, no. 2. Moscow, 1960.
Nagorskii, V.D. “Upravlenie dvigateliami postoiannogo toka s pomoshch’iu impul’sov povyshennoi chastoty.” Izv. AN SSSR: Otdelenie tekhnicheskikh nauk, 1960, no. 2.