SU1493990A1 - Variable power supply - Google Patents

Abstract

The invention relates to electrical engineering, in particular, to voltage regulators and stabilizers, and can be used in power supply systems for electronic equipment. The purpose of the invention is to reduce dynamic losses, increase reliability, load capacity and noise immunity, enhance functionality by providing the ability to work from any mains supply, as well as the ability to operate as a voltage, current or power regulator. The power source operates on the principle of multi-band frequency-pulse-width modulation. With a gradual change in the frequency of the multi-phase pulse generator 1, both the frequency and the width of the pulses in each control zone change. At the same time, the duration of the pulse formed by each single-ended cell 3 ... 8 of summing converter 2 is unchanged and is set by the waiting multivibrators 14 ... 19. Dynamic losses are reduced at minimum output voltage levels by reducing the frequency of operation of the cells 3 ... 8. This allows an increase in the current carrying capacity of each cell 3 ... 8, the operation time of which is constant and optimal, which increases reliability. The absence of power supply elements that are not resistant to interference leads to an increase in noise immunity. 1 hp f-ly, 2 ill.

Description

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31А93990

The invention relates to electrical engineering, in particular, to voltage regulators and stabilizers, and can be used in electrical power supply systems of electronic equipment.

The purpose of the invention is to reduce dynamic losses, increase reliability, load capacity and noise immunity, expand functional capabilities by providing opportunities to work from any mains supply, as well as working as a voltage or power regulator.

Fig. I is a block diagram of a regulated power supply; 2 shows timing diagrams for the operation of the device.

Consider a block diagram of a regulated power supply on the example of six power cells. The adjustable power source contains a multiphase pulse generator 1, a summing converter 2 made of 25 m single-ended cells 3-8, the power inputs of which form the power input 9, 10 of the summing converter 2, and the outputs the power output 11 and 12 connected to the output terminals, 30 limiting amplifier 13, m stand-by multivibrators 14-19 and block 20 converting and matching voltage levels, inputs 21, 22, 23 connected to the input terminals, 35 and outputs to the power input of the summing converter 2.n waiting multivibrators 14- nineteen included in the connection circuits of the outputs of the pulsed-phase generator 1 pulses and the corresponding control inputs from the single-ended cells 3–8 of the summing converter 2, the multiphase pulse generator I being controllable, the output of the amplifier is connected to the control input of the co-45 torus The -oi restrictor 13, one input of which is connected to the output of the feedback circuit, and the other to the source of the control action. The multi-phase CQ rator 1 pulse is made of an analog-frequency converter 24, the output of 25 pulses to the distributor is 25.

Fig. 2 shows: 26 - the voltage of Paul at the output of the amplifier-limiter 13; 27 - signal at the output of the converter 24 analog-frequency; 28 ... 33 - impulses at the outputs of waiting

multivibrators 14 ... 19, which are similar in duration to the output voltages of single - ended cells 3 ... 8; 34 is the output voltage of summing converter 2.

The regulated power supply operates as follows.

The voltage source of the control action Uy is supplied to the direct input of the amplifier-limiter 13, the inverting of which is intended for connecting the voltage of the UPC feedback. The error signal 001 and y- and OS is limited to maxi. the minimum and minimum voltage level due to the limited range of variation of the output voltage of the regulated power source.

Converter 24 generates short pulses, the frequency of which is proportional, (Fig. 2. 27).

The error signal Uo is fed to the converter 24 analog-to-frequency, which generates a sequence of pulses 27 at the output, whose frequency is proportional to the voltage of the error 26. The pulse distributor 25 distributes the pulses 27 alternately to the waiting multivibrators 14-18 in such a way that the first pulse 27 enters the input of the multivibrator 14, the second at 15, the third at 16, etc., then the seventh pulse arrives at the input of the multivibrator 14 and the cycle repeats (t ,, tj, tj). The leading edges of the pulses 28-33 at the outputs of the multivibrators correspond in time to the pulses of the sequence 27.

With a smooth decrease in the control action, the operation cycles of all cells are repeated. At the same time, at high frequency, the first cycle is minimal; time - to t ,; the second is more: from t to tj and the third is even more: from t.

before

etc.

By the pulses arriving at the waiting multivibrators, the latter are triggered and each of them generates a pulse of the same duration 28-33, which are set in power by the converter cells 3-8. Converter 2 summarizes the voltage from single-ended cells and generates a total current in the RH load. Let each cell form a current similar in form

using and matched amplitude signals 28-33. The geometric sum of these pulses gives us the resulting FOR curve, in which five adjustment zones are viewed (Fig. 2). In each zone, the pulses have a different duration, like pulse-width modulation, however, the frequency is different at each of the intervals, therefore the total curve 34 of the output voltage corresponds to multi-band frequency-width-pulse modulation. In this case, the duration of the pulse formed by the cell does not change from clock to clock.

In each cell, the duty cycle changes due to a change in the length of the pause, and not the pulse, as in L lHM. The mains voltage (in our case, AC) converts the voltage level conversion unit 20 into a constant voltage. The output voltage of the unit 20 is adjusted by means of summing converter 2 and filtered by the same converter and capacitor C. Each single-cycle cell is made of chokes L, key K and diode VD and operates as follows. When the output of the standby multivibrator 14 generates a signal 28 (FIG. 2), which opens the key K, while the current from output 9 of block 20 flows through the circuit: RH-L to output 10. Once the key K is closed, the stored energy in the inductance L through the diode VD enters the load Ki. The duration of the open state of each cell key at all levels of the output voltage is constant, only the frequency and tracking changes. The maximum level in the first zone 1 (Fig. 2) is obtained when the cell keys are alternately open while the frequency of the control pulses from the code of each pending multivibrator is equal to

V8

 1 / t,

m,

Where

tn pulse duration; m is the number of single-ended cells. Increasing the frequency of the control pulses as the control voltage Uy increases, there are times when two keys are simultaneously open, and a second control zone is formed. When at the same time

five

0

five

but three keys are open, the U-zone is formed, and so on. Thus, in the load, multiband frequency-pulse-width modulation is formed. With a gradual change in frequency, the pyrin frequencies of the pulses in each control zone also change, although the open state of the keys of the cells is unchanged.

The total dynamic losses in the regulated power supply are the same as at the maximum output voltage level, and at the minimum levels, the voltage is less in hectare, because the cell frequency decreases by a factor of m. This makes it possible to increase the current carrying capacity of each power cell at lower voltage levels and to use this source advantage in its operation with constant power in a given control range.

Decreasing the output voltage to zero, for example, during a short circuit in the load. the frequency of the pulses is minimal and is determined only by the continuity of the current in the drossel x (unit-ten Hz). Possible short-circuit modes do not lead to the failure of key elements due to low dynamic losses in the presence of current feedback, which leads to an increase in the reliability of the power supply.

Reliability is also increased due to the fact that the converter cell is more reliable, since it always works the same time and does not arise. There are modes when it is necessary to form short pulses that significantly load the key elements due to the fact that the dynamic losses of the switching edges and shutdowns are combined. At the same time, the parasitic parameters of coiled goods have the most harmful effect. The capacitances of the windings are recharged, and therefore current surges occur through the keys, which increases the dynamic losses, and the transistor switches are prone to secondary breakdown.

Thus, an adjustable power source allows to reduce dynamic losses due to a lower frequency for a certain and optimal duration of power.

0

five

0

0

five

in the cell, the load capacity of the cell is increased at minimum output voltage levels, since it is not necessary to form short pulses that are not optimal for energy transfer. The noise immunity of the power supply has increased, since there are no elements that are unstable to interference, such as the comparator (PWM) Q and the FPG. The level of interference generated by the power circuit is reduced, since with a constant pulse width (key open) it is possible to use optimal circuits to form a switching path 15, which also increases the reliability and efficiency of the device. The regulated power supply has enhanced functionality and can perform the following additional functions: it can operate from any power supply network by introducing unit 20; It can operate as a voltage, current or mop regulator, for which 25 is provided an input for connecting current, voltage or power feedback circuits.

Formula of invention 30

Claims (2)

1. An adjustable power supply containing a multi-phase pulse generator and a summing converter, made of m single-ended cells, the power inputs of which form the power input of the summing converter and the outputs An output that is connected to output voltages, characterized in that, in order to reduce dynamic losses, improve reliability, load capacity and noise immunity, enhance functionality by providing the ability to operate as a voltage, current or power regulator, an amplifier is introduced into it limiter and waiting multivibrators, the power input of the summing converter is connected to the input cables, the waiting multivibrators are included in the output connection circuits of the multiphase generator pulses torus and respective control inputs of the summing transformer single ended cell, polyphase pulse generator is controllable, to a control input of which is connected the output of limiting amplifier having one input connected to an output feedback circuit, and the other - with a source of exposure control. 2. Source pop.1, which differs from the fact that, in order to expand its functionality by providing the possibility of operation from any mains supply, a voltage conversion unit is inserted into it and the voltage levels included in the open circuit of the circuit are input terminals and the power input of the summing converter. Ki -vj Hh | -41. " J Jd P Of jCafc-.CVjtVN "NCNj" Ne; N v tv i WITH " f f f Jd P Cafc-.CVj