SU1181096A1 - A.c.voltage-to-d.c.voltage converter - Google Patents

Abstract

AC VOLTAGE VOLTAGE CONVERTER, containing a booster transformer connected to the input terminals, and one terminal, one of the DC terminals of which is under the keys to the first output terminal, and the other DC output through the h series-according to the connected diodes to the second output terminal booster rectifiers with capacitors connected by inputs to the corresponding windings of booster transformer, n transistor switches and a control device, characterized in that that, in order to improve manufacturability and functional reliability, a pulse transformer and n-1 static triggers were introduced into it. , while the booster rectifiers are connected in series sequentially, the positive | output of the first booster rectifier through the collector-emitter junction of the first transistor switch is connected to the cathode of the first diode, the negative output of each of the subsequent booster rectifiers through the emitter-collector junction of the corresponding transistor switch - to the anode of the corresponding diode, the common output of the first and the second booster voltage through the primary winding of the pulse transformer connected to the (L cathode of the second and anode of the first diodes, and the emitter-base transitions of all the following transistors follow the first through static triggers connected to the corresponding secondary windings of the pulse transformer, and the control unit is single-channel as a two-way comparator connected via the first input -, the drive with the winding of the booster transformer, the second input, with the source of the reference voltage, the output - with the emitter-bae transition of the first transistor switch.

Description

. The invention relates to electrical engineering and to be used in power supply devices.

The purpose of the invention is to improve the manufacturability and functional reliability.

Fig. 1 is a schematic of a constant-to-voltage converter with three voltage boosting rectifiers in FIG. 2 graphs explaining its principle of operation in FIG. 3 - static trigger scheme.

The primary winding of the volt-down converter transformer 1 and the input of the rectifier 2 are connected in parallel to the input terminals 3 of the converter. The output of the rectifier 2 is connected in series - according to the connected diodes 4 - 6 to the output terminals 7 of the converter. The output windings of the booster transformer 1 are connected to the inputs of the corresponding booster rectifiers 8–10. The output of the booster rectifiers 8-10 is connected in series, and the average output of the rectifiers 8 and 9 is connected through the primary winding of the pulse transformer 11 to the cathode of diode 5 and the anode of the diode 4 The positive output of the rectifier 8 through the collector-emitter junction of the transistor switch 12 is connected to the diode 4 of the diode 4, and the negative leads of the rectifiers 9 and 10 through the emitter-collector junction of the transistor switches 13 and 14 are connected, respectively, to the anodes of diodes 5. and 6. The respective secondary windings of an impulse transformer 11 are connected to the inputs of the static triggers 15 and 16. The output of the static trigger 15 is connected to (Transition 6a3a-3MnTTepj transistor switch 13, and the output | of the trigger | trigger 16 - to the base-emit | ter transition of the transistor switch 14. The control body 17 is made on a two-input comparator 18, the output of which is connected to the base emitter of the key 12. The first input of the comparator 18 is connected via a rectifier 19 with a booster winding of the transformer 1, and the second input is connected to the source of the reference voltage (to the zener diode 20). Load 21 is connected to output pins 7.

FIG. 2 shows time diagrams, where U is voltage at VU4, U5,

and. straightener

booster voltage on diodes 4, 5 and 6; Ii current pulses in the primary winding of a pulse transformer 11 ;. and y is the output voltage of the converter; U.j, is the voltage at the first and second inputs of the comparator 18; C is the output voltage of control body 17; E is the average value of the output voltage of the converter; the cx diagram corresponds to the minimum and the iS diagram to the maximum voltage value at input 3 of the converter.

The adjustable variable-to-constant voltage converter operates as follows.

With the minimum voltage of the power source connected to the input terminals of the converter 3, the instantaneous values of the input voltage U applied to the first input of the comparator 18 exceed the reference voltage Ujp at the second input of the comparator 18 during the smaller half of the converted voltage - moments time t - t. , t (fig. 2ci). As a result, at the output of the control body 17 (at the output of the comparator 18), rectangular voltage pulses C, are generated that unlock the key 12 at times when the reference voltage is greater than the voltage. The key 12 opens at the time tj, and the booster capacitor of the miter 8 begins to discharge to the load 21 through the primary winding of the pulse transformer 11, the diodes 5 and 6 and the rectifier 2. The current 1 flowing through the primary winding of the pulse transformer 11 forms the secondary windings of the pulse transformer, voltage pulses switching the static triggers 15 and 16 to the state that enables the keys 13 and 14. The voltages of the capacitors of the booster rectifiers 9 and 10 are connected, respectively, pairs llelno diodes 5 and 6 and the load 21 (at the output vy3 waters 7) is formed voltage U equal to the sum voltage of the rectifier 2, 8, 9 and 10 (excluding losses due to circuit elements). At the moment when the key 13 is opened, the capacitor m 9 is discharged not through the winding of the pulse transformer 11, but through capacitors and 10. Therefore, at times tj and t, the current through the primary winding of the pulse transformer 11 has the form of a positive pulse 1 (FIG. 2 At the instants of time when the instantaneous values of voltage 11 begin to exceed voltage V, the leading edge of the pulse U. of the control of the transistor switch 12, i.e. for the time Ts-t., T-t the transistor-switch | 2, closes, and booster capacitor rectifier 8 is It is connected to the load supply circuit. However, at times t and t, the booster capacitor rectifier 9 remains connected to the output voltage U through the pulse transformer 11, diode 4, rectifier 2 and 1.0, and the open key 14, t i.e. in the primary winding of the pulse transformer at times t and C, a current pulse I of negative polarity is formed. As a result, voltage pulses are generated on the secondary windings of the pulse transformer 11, switching the static triggers 15 and 16 to the position corresponding to The closed state of the keys 13 and 14. Thus, the keys 13 and 14 are automatically switched synchronously with the key 12. With the maximum value of the source of the converted voltage (Fig. 2B) the instantaneous voltage values exceed the voltage and for most of the half period, therefore, the open time of the keys 12, 13 and 14, respectively, decreases, and the voltage of the additional voltage in the output voltage U decreases. At the same time, the average value of the output voltage E remains almost unchanged. It follows from the principle of operation that by changing the reference voltage U, jQ (Fig. 1) with a potentiometer connected in parallel to the zener diode 20, the average value of the output voltage E can be adjusted twice if the voltage on the secondary windings of the booster transformer 1 provides sum j apHoe for voltage booster rectifiers. 8 - 10, equal to the amplitude value of the variable voltage being converted, while the voltage on the keys 12 - 14 is equal to one third of the amplitude value of the input voltage. With an increase in the number of booster rectifiers and transistor switches, it is possible to further reduce the load factor of the voltage across the transistor switches of the converter, while the regulator remains single-channel (controls only the first transistor), and the subsequent switches are controlled by static triggers.

and.

but

VV

about

and

17

LL

but,

p k oi.

7h

4MA

eleven

R

about

FIG. 2

Claims (1)

AC VOLTAGE CONVERTER TO DC, containing a boost booster transformer and a rectifier connected to the input terminals, one of the DC outputs of which is turn-key to the first output terminal, and the other DC output through n series-connected diodes to the second output terminal, η of boost boosters with capacitors connected by inputs to the corresponding windings of the boost transformer, η transistor switches and a control element, characterized in that, with In order to improve manufacturability and functional reliability, a pulse transformer and p-1 static triggers are introduced into it, while the boost boosters are connected in series with the outputs, and the positive output of the first boost rectifier is connected to the cathode of the first diode through the collector-emitter junction of the first diode, the negative output of each of the subsequent boost rectifiers through the emitter-collector junction of the corresponding transistor switch - to the anode of the corresponding The ode, the common output of the first and second boost rectifiers through the primary winding of the pulse transformer is connected to the cathode of the second and the anode of the first diodes, and the emitter-base transitions of all subsequent transistor switches following the first are connected via static triggers to the corresponding secondary windings of the pulse transformer, and the control is single-channel in the form of a two-input comparator, connected ¹ by the first input through an outlet-, a straightener with a voltage-boosting winding. transformer, the second input '· with a reference voltage source, the output - with the emitter-base transition of the first transistor switch. SHGNPTPtz I