SU535690A1 - Frequency converter - Google Patents

Description

The invention relates to radio engineering and can be used in radio engineering installations for various purposes to obtain infrared-frequency sinusoidal oscillations of a controlled frequency.

A known frequency converter is made according to a scheme with an intermediate conversion of an input alternating voltage to a direct current 1.

The closest technical solution is a frequency converter containing a rectifier, a master oscillator and a series-connected filter, a two-pole thyristor switch, the control inputs of which are connected to the corresponding outputs of the control unit, and a load 2.

However, the known transducers have low efficiency at low frequencies.

In order to increase the conversion efficiency, in the proposed converter, between the rectifier output and the filter input, parallel-connected shock excitation circuit and a thyristor switch are inserted, the control input of which is connected to the output of the master oscillator.

The drawing shows a structural electrical circuit of a frequency converter.

The frequency converter contains a rectifier 1, a master oscillator 2, a filter 3 in series and a two-pole thyristor switch 4, the control inputs of which are connected to the corresponding outputs of the control unit 5, and the load 6. Between

the output of the rectifier 1 and the input of the filter 3 are connected in parallel to the shock excitation circuit 7 and the thyristor switch 8, the control input of which is connected to the output of the master oscillator 2.

The frequency converter operates as follows.

The pulsating voltage from the rectifier 1 is supplied to the parallel-connected circuit 7 and the thyristor key B, from which the voltage pulses are removed, the frequency is determined by the frequency of the master oscillator 2, the duration by the parameters of the circuit elements 7, and the amplitude by the instantaneous value of the network voltage opening moment

thyristor key 8. Since the frequency of the triggering pulses differs from the doubled frequency of the network by the magnitude of the doubled frequency of the output voltage, one pulse is removed from circuit 7 and thyristor key 8

for half the period of mains voltage.

Since the amplitude of such pulses depends on the instantaneous value of the network voltage at the time of the start of the thyristor switch 8, their envelope is a module

sinusoidal output voltage.

The filter 3 converts the pulses arriving at its input into unipolar sinusoidal voltage pulses with a double output voltage frequency, which is then fed to the input of two-pole thyristor switch 4 and to the input of the control unit 5, which generates a signal each time the output voltage , changing under the sinusoidal law, decreases to zero. This sygnal is fed to the control electrodes of the corresponding thyristors of the two-pole thyristor switch 4.

On the load 6 connected to the output of the polypolar thyristor switch 4, there is a sinusoidal voltage, the frequency of which is determined by the difference between the double network frequency and the double frequency of the master oscillator 2, and the amplitude is determined by the value of the network voltage and the parameters of the circuit elements 7.

Maximum currents in the converter circuits flow through the saturated thyristor switches 4, 8, as a result of which a high efficiency is ensured.

Claims (2)

1. Power supplies on semiconductor devices, edited by S. D. Dodik, publishing house “Soviet Radio, Moscow, 1969, pp. 281-291. 2. USSR author's certificate number 425284, M. Kl.2 N 02M 5/42, 1971 (prototype). H | L.1 I I I one tbzid J L