SU656162A1 - Stabilized dc-to-dc voltage converter - Google Patents

Description

but, and with the input of the first frequency divider through the first inverter, the output of the pulse-width modulator is connected to the first inputs of the AND circuits of the first pulse selector directly, and to the first inputs of the And pulse selector circuits of the second pulse selector through the second inverter and the second pulse selectors are connected to the inputs of the respective frequency dividers, and the power supply circuits of the preamplifiers are connected to the output of the auxiliary voltage input voltage input. FIG. 1 shows a circuit diagram of the device; FIG. 2a, 6 are timing diagrams of the operation of the device, respectively, at lower and higher values of the output voltage. The stabilized converter contains a power rectifier 1 and a filter 2 connected to the output of a power amplifier made of a push-pull transformer circuit on transistors 3, 4, the base of each of which is connected via resistors 5, 6 to the outputs of the winding 7, 8 of the control and through diodes 9, U - with the outputs of the locking winding 11, 12, pulse-width-modulated module 13, the first input of which through the feedback circuit 14 is connected to the output of the device, and the second input through the driver of the saw-tooth voltage 15 is connected to the output of the redepaTOp a 16, the first and second inflow amplifiers, made on transistors 17, 18 and 19, 2 O according to the push-pull circuit with output transformers 21, 2, on which control windings 7, 8 and locking winding 11, 12 are placed, two pulse selectors, containing two 23, 24 and 25, 26 circuits each, the outputs of which are connected respectively to the bases of transistors 17, 18 and 19, 2O preamplifiers, two frequency dividers 27, 28, two inverters 29, 30 and an auxiliary voltage regulator 31. input supply voltage specifying the generator. 16 It begins to produce a sequence of rectangular pulses (FIG. This sequence is inverted by an inverter 29 and fed to the input of the first frequency divider 27. From the outputs of frequency divider 27, the direct and inverse sequence of rectangular pulses is removed at a frequency two times lower than the frequency of the master oscillator 16 ((Fig. 2). From a rectangular voltage generated by a master oscillator 16 using a sawtooth voltage driver 15, a symmetrical sawtooth voltage (and, - in FIG. 2) is obtained with a frequency equal to the frequency of the master oscillator 16. This voltage blunt to the input of the pulse-width modulator 13. The pulse-width modulator 13 converts a constant output voltage supplied to another input through the feedback circuit 14 into pulses, the duration of which is inversely proportional to the output voltage, and the frequency is equal to the frequency of the master oscillator 16 (U, jj in Fig. 2). From the output of the pulse-width modulator 13, the voltage is applied to the first inputs of the And 23, 24 circuits of the first pulse selector. The second inputs of the circuits And 23, 24 are energized from the outputs of the first frequency divider 27. The pulse from the output of the pulse-width modulator 13 passes to the output of that circuit And, at the second input of which there is a pulse from you-. of the frequency divider 27, Since the frequency of the pulse-width modulator 13 is twice the frequency of the output pulses of the frequency divider 27, then the output of each of the circuits is And 23, 24 pulse, equal in duration to the pulse from the output of the pulse-width modulator 13 will appear once per period of frequency of operation of frequency divider 27. Thus, in the code of each circuit 23, 24 there are sequences of pulses shifted out of phase by half the frequency of operation of frequency divider 27 with a duration equal to the duration of the output latitude pulses. but a pulse modulator 13 and a frequency equal to the frequency of operation of the divider 27 (Ug and Fig. 2). From the codes of the AND 23, 24 circuits, the pulses arrive at the bases of the transistors 17, 18 of the first preamplifier, alternately opening them for the time determined by the pulse duration from the output of the pulse-width modulator 13. A two-polarized voltage will be generated on the windings of the transformer 21 with a pause at zero (Ug in Fig. 2). The voltage removed from the secondary control winding 7, 8 is used to unlock the transistors 3, 4 of the power amplifier. The change in output voltage supplied through feedback circuit 14 is processed by a pulse-width modulator 13, which varies the duration of the pulse being formed so that the average value of the output voltage remains constant. The second pulse selector, which contains two circuits, And 25, 26, works similarly to the nepomo. Here, the addition of pulses from the output of a pulse-width modulator 13 through an AO inverter (Ujo in FIG. 2) with a direct and inverse pulse train From the outputs of the second frequency divider 28. The launch of the second frequency divider 28 is carried out by voltage pulses coming directly from the output of the master oscillator 16, due to the fact that the start of frequency dividers 27, 28 is performed by the same fronts, and between ohm of the master oscillator 16 and the input of the first frequency divider 27 is turned on by the inverter 29, then the pulse sequence from the outputs of the second frequency divider 28 will be phase-shifted relative to the pulses from the outputs of the frequency divider 27 by half the frequency of the master oscillator 16 (Urtc in FIG. 2). it is achieved that the falling edge of the I1 pulses from the outputs of the circuits And 23, 24 and the leading edge of the pulses from the outputs of the circuits And 25, 26 are formed simultaneously (u25 2b F for time duration and ikshulsa. On the windings of the transformer 22, a two-pole rectangular voltage with a pause at zero (Fig. 2) will also be inverse, as compared with the voltage on the windings of the transformer 21, the voltage removed from the secondary windings 11, 12 of the transformer 22 through diodes 9, 10 is supplied to the bases of transistors 3, 4 and is used for the formed locking ah. As the inputs of the AND 25, 26 circuits supply voltage from the output of the pulse-width modulator 13 through the inverter 30, then as the input voltage rises the coils of the transformer 21 will decrease, and on the windings of the transformer 22 will increase. Due to this, the device simultaneously modulates the unlocking and locking voltages. This causes the transistors 17, 18 to be closed at the time of forming the blocking voltage, and the voltage on the control half windings 7, 8 is zero. Due to this, power losses are excluded due to the simultaneous operation of two series-connected EMF induced on the secondary windings of transformers 21, 22 at resistance 5 and 6 in the base circuit of transistors 3, 4 of the power amplifier, and through the resistance 5 or 6 a small current flows to the no-load current of one of the half-currents 7, 8 of the transformer 21, in addition, the loss of power spent on compensation of the encountered currents is reduced. The absence of a pulse-width modulator key connected between the middle point of the prohibiting winding and the emitters point of the transistors of the power amplifier, allows, at the same switching current, to reduce the voltage on the locking winding, which leads to a corresponding decrease in the power consumed. The power supply of the preamplifiers from the auxiliary voltage regulator leads to the fact that with an increase in the current voltage, the power expended to control the transistors of the power amplifier does not increase, since the amplitude of the voltage pulses on the control and locking windings does not increase, and the pulse duration the base current decreases, resulting in a decrease in the average current consumed from the auxiliary voltage regulator. The power at prohibitive voltage is expended only on the absorption time of excess carriers in the base, which is an insignificant part of the period. All these advantages lead to a decrease in the power expended to control the transistors of the power amplifier, and therefore to an increase in the headroom of the device, which distinguishes the offered converter from the nf ootype,

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A constant-voltage constant-voltage converter in constant-current with a power supply with a filter, connected to the output of the POWER amplifier made through a push-pull transformer circuit on the transistor, which is connected through resistors with control winding leads and through diodes with The waters of the locking winding and the width of the ™ pulse modulator, the first input of which is connected to the input through the feedback circuit, and the second input through the sawtooth driver is connected to the output of the In order to increase the efficiency5, two preamplifiers were added, implemented on transistors in a push-pull circuit with output transformers, on which, respectively, a control winding to the locking winding, two pulse selectors, containing two circuits and two frequency divider and two inverters,

In this case, the outputs of the first and second selectors I and I of the pulses are connected to the transistor bases of the respective preamplifiers, the output of the master oscillator is connected to the input of the second frequency divider directly HOj and to the input of the first frequency divider through the first inverter, the output of the pulse width modulator is connected to the first To the circuits of AND circuits of the first pulse selector directly, and to the first inputs of the circuits AND of the second selector of pulses - Through the second inverter, the second inputs of the circuits AND of the first and second selectors are impulses They are connected to the outputs of the respective clock TIMERS and the power supply circuits of the preamplifiers are connected to the output of the auxiliary voltage regulator introduced.

Sources of information taken into account in the examination

1. USSR Author's Certificate No. 479101, Q 05 F 1/64, 1973.

2, USSR Author's Certificate No. 491941, 3 O5 F 1/64, 1974.

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