SU536574A2 - Three-phase ferromagnetic frequency divider - Google Patents

Description

one

The invention is intended to trigger hard-excited, three-phase ferromagnetic frequency dividers, which are used to obtain low frequencies.

At present, the launch of ferromagnetic frequency dividers is carried out by a discharge pulse, saturating the core of the nonlinear element, of precharged capacitors.

Known three-phase frequency divider autom. St. No. 462258.

To turn on the known frequency divider, it is necessary to disconnect the divider from the power source, charge the capacitor, disconnect the charger from the circuit and connect to the mains, its other drawbacks include the duration of the process of recharging the capacitors, the presence of an additional DC source , as well as the unreliability of the circuit, due to failures when it is turned on.

The purpose of the invention is to increase the reliability of the launch and increase the speed of the divider.

To do this, on the nonlinear element of the proposed three-phase ferromagnetic frequency divider, an additional winding is introduced, closed through the thyristor and a control resistor.

In the control electrode circuit of the thyristor there is a single-phase source of low-frequency pulses; parallel to one of the phases of the secondary winding, a voltage relay is connected to control the onset of parametric resonance.

The drawing shows the electrical circuit of the proposed divider, where 1 is a thyristor, 2 is a voltage relay, 3 is a control unit, 4, 5 are normally closed (n.) Voltage relay contacts, b is an additional winding on the core of a nonlinear divider element ,

7- adjusting resistor in the additional winding circuit, 8 - three-phase frequency divider by three.

When the start-up circuit is turned on, the thyristor 1 is unlocked by pulses arriving at the frequency / s of the control unit 3, for example, a multivibrator, a Schmitt trigger and a single-phase ferromagnetic divider can be used.

At the same time, a pulsating current flows through the additional winding 6, which can be changed by the adjusting resistor 7. A periodic biasing of the core of the nonlinear element occurs at a frequency /.

The three-phase frequency divider produces powerful subharmonic oscillations due to parametric resonance.

The voltage on the nonlinear element and divider 8 co-capacitors increases sharply, causing the voltage relay 2 to operate, the latter disconnecting the thyristor control unit with its normally closed contacts 5, and the current flow in the auxiliary winding circuit stops.

When subharmonic oscillations break down, the voltage on the nonlinear element and capacitors drops, the relay switches off the core, its normally closed contacts 4, 5 turn on the control unit and the thyristor control circuit. A three-phase divider restarts in the sequence described above.

Claims (2)

1. Three-phase ferromagnetic frequency divider according to ed. St. No. 462258, characterized in that, in order to improve the start-up reliability and speed, an additional winding is introduced on the non-linear element, closed through the thyristor and the control resistor. 2. The frequency divider according to claim 1 is distinguished by the fact that a voltage relay coil is connected parallel to the capacitors of the main circuit, one pair of contacts of which is connected in series with the control electrode of the thyristor and the other in series with the power supply of the thyristor control unit.