SU57525A1 - Device for stabilizing the speed of a DC motor - Google Patents

Description

Devices are already known for stabilizing the rotational speed of a direct current electric motor using the latter for additional excitation windings that are automatically activated when the rotation speed of the electric motor deviates from a predetermined value.

The present invention relates to such a device and consists in a specific form of its implementation.

The drawing shows a diagram of the device.

In series with the additional windings and excitation Og of the electric motor, connected opposite to each other, two thyratrons TI and, respectively, T are connected. The nets of the thyratrons are connected to the semirings Yav and Yab of the switch, driven in rotation from the electric motor. The adjacent semiring K and K of this commutator, which, together with the semiring K and K, are closed with a common ZZ / 2 brush, are connected to the ends of two second (transformer 7 windings; the primary winding of this transformer through rings / Cj and K by the same switch, interlockable with U, periodically included

in the circuit of the source of electrical current. The switchboard has two more plates L, and / fg, closed with a common brush ZZ /, made one in the form of a flat ring, and the second in the form of a cut one. These plates are connected between the middle point of the additional windings Oj and Oo and the middle point of the common incandescent circuit of the TI and Gd thyratrons.

G3 thyratrons are normally locked by negative bias. The brushes of the switch are located on the same straight line, and the contact plates are shifted relative to each other and relative to the brushes as shown in the drawing.

The operation of the device is as follows. When the brush ZZ / 1 is in position I, it closes the plates / Ci and L, thus turning on the primary winding of the transformer in the current source circuit. The rise time of the voltage in the transformer otorichnaya winding must be equal to the time required to rotate the motor core through 180 ° (at a synchronous speed).

If the motor's mouth p rotates synchronously, then the voltage in the secondary winding of the transformer T

occurs when the brush /// o is in position II, i.e., between the contact plates, and the voltage on the grid of locked thyratrons is not applied. Thus, no change in motor speed will occur. If the electric motor rotates at a speed lower than synchronous, the voltage in the secondary winding of the transformer T is worse until the time when the brush U comes to position II, i.e. when the plates are closed K and therefore the voltage of this winding will be applied on the grid of the thyratron T. Since the direction of the voltage pulse is chosen so that it removes the displacement on the grid of the thyratron TI, the latter will ignite and turn on the current in the additional winding O of the excitation of the electric motor, creating a magnetic flux in one direction main flow excitation. Upon further rotation, the brush holder will come to position III, in which the brush U opens the plates Kj and the anode circuit of the thyratron T opens, it goes out and comes back to light only when the next voltage pulse is applied to its grid, i.e. cycle - the next turn of the electric motor, if the latter rotates out of sync.

If the motor rotates at a speed greater than synchronous, then the voltage pulse through the ZZ / 2 brush and the plates / and Kf closed at that moment will be fed to the grid of the thyratron G, which will turn on the winding Oj, which creates a magnetic flux directed towards the main flow excitement.

The voltage pulses in the secondary winding that are formed when the primary winding is turned off will not affect the operation of the circuit, since they will only increase the negative bias on the thyratrons.

In addition, the current in the primary winding is turned off (as can be seen from the diagram) some time before the end of the rotation of the brush holder so that the reverse pulses in the secondary winding take place before the end of the rotation through 360 ° and do not disturb the operation of the circuit at the beginning of the cycle, t. e. when the brush holder is in position I.

Thus, in the proposed device, the speed adjustment is carried out at each revolution of the electric motor and allows for a predetermined duration of one revolution with significant accuracy and with even greater accuracy of the average speed of the electric motor.

The authors note that in the described device it is possible to adjust the speed within a small range, i.e., to change the value of the synchronous speed. This is achieved by changing the rise time of the voltage in the secondary winding of the transformer T.

The subject matter of the invention.

A device for stabilizing the speed of a direct current electric motor using the latter for an additional, excitation windings, which are automatically activated when the speed changes, characterized in that Oi and O2 are connected to each of the windings. connected in parallel, are normally connected normally closed thyratrons T and, respectively, T, unlocked by a pulse transformer T connected to the grid circuits and the common anode circuit of the thyratrons through a switch rotated from the electric motor, the individual elements of which are located relative to each other so that The transformer is connected to the grid circuit of the corresponding lamp only when the speed of rotation of the electric motor deviates from the set one.