RU2767490C1 - Method for reducing the noise level of a compensation dc voltage stabilizer with continuous regulation - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: invention relates to the field of electrical engineering and can be used in the construction of low-noise compensation DC voltage stabilizers with continuous regulation, made on the basis of reference voltage sources of wide application. A method for reducing the noise level of a compensation DC voltage stabilizer with continuous regulation is carried out when performing the operations of generating a feedback voltage, generating a reference voltage, generating a mismatch voltage, amplifying the mismatch voltage, regulating the output voltage, and suppressing the noise of the reference voltage.

EFFECT: reduction of noise voltage while increasing the stabilization factor of compensation DC voltage stabilizers with continuous regulation.

1 cl, 7 dwg

Description

The field of technology to which the invention belongs

The invention relates to the field of electrical engineering and can be used in the construction of low-noise compensation DC voltage stabilizers with continuous regulation, made on the basis of reference voltage sources of wide application.

State of the art

A known method of constructing compensation DC voltage stabilizers with continuous regulation [Kitaev V.E., Bokunyaev A.A., Kolkanov M.F. "Power supply of communication devices", M.: Svyaz, 1975, p. 187, fig. 8.8], [B.I. Artamonov, A.A. Bokunyaev. "Power sources of radio devices", M.: Energoizdat, 1982, p. 145, fig. 5.10], [L.F. Zakharov, M.F. Kolkanov. "Power supply of communication devices", M.: GOU "Educational and methodological center for education in railway transport", 2007, p. 128, fig. 5.9], which is a closed system of automatic control with negative feedback, characterized by:

- input voltage stabilization factor

, (1)

, (one)

,

- изменение напряжения на входе, выходе стабилизатора;where

,

- voltage change at the input, output of the stabilizer;

,

- напряжения на входе, выходе стабилизатора;

,

- voltage at the input, output of the stabilizer;

- ток нагрузки;

- load current;

- ripple smoothing factor

, (2)

, (2)

,

- амплитуды пульсации входного и выходного напряжений стабилизатора;where

,

- the amplitude of the ripple of the input and output voltages of the stabilizer;

- напряжение шума на выходе стабилизатора,

- noise voltage at the output of the stabilizer,

and based on the performance of a number of operations:

1) formation of feedback voltage;

2) formation of the reference voltage;

3) mismatch voltage formation;

4) amplification of the mismatch voltage;

5) regulation of the output (stabilized) voltage.

A possible implementation of the method for constructing a compensating DC voltage regulator with continuous regulation is a series regulator circuit [B.I. Artamonov, A.A. Bokunyaev. "Power sources of radio devices", M.: Energoizdat, 1982, p.149, Fig.5.12] consisting of the following functional units: control element (RE) - transistor VT1; the comparison circuit (CC) consists of resistive voltage dividers R1, R2, R3 and the input circuit of the transistor VT2; DC amplifier (UPT) - transistor VT2 with a collector load Ry; reference voltage source (ION) is a single-stage parametric voltage stabilizer, consisting of a zener diode VD1 and a quenching resistor Rg. To smoothly adjust the output voltage of the stabilizer, a potentiometer R2 is included in the voltage divider, from the engine of which voltage is supplied to the base of the transistor VT2. The reference voltage of the zener diode is applied to the emitter of the transistor VT2. The upper arm of the divider is designated as RI, and the lower arm is RII. To ensure stable operation of the stabilizer, capacitance C is included at the output.

According to this method, the stabilizer works as follows. Suppose that the voltage at the input of the stabilizer has increased, then the voltage at the output of the stabilizer should increase, as well as the voltage on the lower arm of the divider (RII) of the comparison circuit U RII \ _u003d U _b2 . An increase in the potential of the base of the transistor VT2 leads to an increase in both the base current of the transistor VT2 and the collector current I _K2 . As a result, the voltage drop across the UPT load increases.

, (3)

, (3)

which leads to an increase in voltage between the collector and the base of the regulating transistor VT1. Therefore, the resistance between the collector and emitter of the transistor VT1 increases, the voltage drop U _KE1 increases, ensuring the stabilization of the output voltage. Stabilization of the output voltage is also assumed in the event of a change in the load current. With an increase in the load current, the value of both the output voltage and the voltage on the lower arm of the divider of the comparison circuit decreases U _RII . As a result, the base current of the transistor VT2 and the collector current I _K2 decrease. Consequently, the voltage drop across the resistor R _U decreases, therefore the resistance between the collector and emitter of the regulating transistor VT1 decreases, and U _{KE1 decreases} , ensuring the stabilization of the output voltage.

Due to the fact that the stabilizer is a closed-loop automatic control system with negative feedback, then in the presence of destabilizing factors - changes in the input voltage (ΔU _in ), consumer current (ΔI _n ), voltage at the output of the reference voltage source (ΔU _op ), so there will also be a change in the output voltage (ΔU _out ), expression (4)

, (4)

, (4)

where K ₁ is the voltage transfer coefficient of the transistor VT1 in the switching circuit with a common emitter;

K _y - voltage transfer coefficient of the UPT (transistor VT2 in the switching circuit with a common emitter);

r _K1 - resistance of the collector junction of the transistor VT1;

r _Ku - resistance of the collector junction of the transistor VT2;

α - transfer coefficient of the resistive divider СС

(5)

(five)

α′ - transfer coefficient of the resistive divider SS, taking into account the influence of the input resistance of the UPT (transistor VT2)

(6)

(6)

- напряжение собственных шумов ИОН, порождающее напряжение шума на выходе стабилизатора

- intrinsic noise voltage of ION, generating noise voltage at the output of the stabilizer

(7)

(7)

,

коэффициент стабилизации примет видTaking into account the assumptions that

,

the stabilization coefficient will take the form

(8)

(8)

As follows from the analysis of expressions (7), (8) and (2), the magnitude of the noise voltage at the output of the stabilizer, the stabilization and smoothing coefficients, are largely determined by both the gain coefficients of the RE K ₁ , UPT K _y , and the noise voltage of the ION.

Reducing the noise of the reference (the use of a low-noise reference) helps to increase the stabilization and smoothing coefficients while reducing the noise voltage at the output of the stabilizer.

, то есть напряжению шума пик-пик

= 0,8 мВ.Figure 1 shows the timing diagram and spectrogram of the noise component of the ION (IMS SPX385-2.5). The SPX385-2.5 IC is characterized by an RMS noise voltage of 120 µV in a frequency band of 10 Hz ÷ 10 kHz, which is equivalent to the noise voltage generated by a resistor with a resistance of 87.5 MΩ in a band of 10 kHz at a temperature of 25

, i.e. peak-to-peak noise voltage

= 0.8 mV.

(напряжение шума пик-пик

= 1,3 мВ).Figure 2 shows the timing diagram and spectrogram of the noise component of the noise voltage at the output of the stabilizer when

(noise voltage peak-peak

= 1.3 mV).

(напряжение шума пик-пик

= 2,1 мВ).Figure 3 shows the timing diagram and spectrogram of the noise component of the noise voltage at the output of the stabilizer when

(noise voltage peak-peak

= 2.1 mV).

и на 0,15% при

.A change in _{ΔU in} by ±10% of U _in led to a change in ΔU _out by 0.68% at

and by 0.15% at

.

The disadvantage of this method and this variant of its implementation is the low stabilization coefficient with a significant influence of the intrinsic noise of the ION on the level of output noise of the stabilizer

A possible implementation of the method for constructing a compensating DC voltage regulator with continuous regulation is a series regulator circuit [G.N. Gorbachev, E.E. Chaplygin. "Industrial electronics", M.: Energoatomizdat, 1988, p. 209, fig. 5.11], made using a UPT based on an operational amplifier (op-amp).

The stabilizer circuit consists of the following functional units: RE - transistor VT; SS - resistive voltage divider R1, R2; UPT - operational amplifier DA; ION - parametric voltage stabilizer, consisting of a zener diode VD and a ballast resistor Rb.

. Столь высокий коэффициент стабилизации является несомненным достоинством данного варианта реализации способа построения компенсационного стабилизатора напряжения постоянного тока с непрерывным регулированием, но лишь в случае использования малошумящего ИОН. As a feature of this circuit is the establishment of the differential voltage supplied to the UPT (voltage removed from the SS and ION) close to zero, followed by a significant amplification (more than 1000), providing the formation

. Such a high stabilization coefficient is an undoubted advantage of this implementation of the method for constructing a compensation DC voltage stabilizer with continuous regulation, but only in the case of using a low-noise ION.

A high gain factor, taking into account the broadband noise of the ION, at its significant level, due to the inertia of the amplifying elements, as well as the reactivity of the load and the capacitance of blocking capacitors (used in the construction of power supply devices), leads to a phase shift in the feedback circuit, which in turn, generates a dynamic error of a closed control system (a decrease in the feedback coefficient mainly in the low and high regions).

The disadvantage of this method and this variant of its implementation in the case of using a widely used ION is the actual:

- reducing the stability of the stabilizer as an automatic control system;

- narrowing the range of permissible changes in the input voltage;

- a significant decrease in the smoothing coefficient relative to the stabilization coefficient;

- high level of voltage noise at the output of the stabilizer.

Disclosure of invention

The technical result that can be achieved using the present invention is to reduce the noise voltage while increasing the stabilization factor of compensation DC voltage stabilizers with continuous regulation.

The technical result is achieved by the fact that in a way to reduce the noise level of a compensation constant voltage stabilizer with continuous regulation, just like the prototype, based on performing a number of operations:

1) formation of feedback voltage;

2) formation of the reference voltage;

3) mismatch voltage formation;

4) amplification of the mismatch voltage;

5) regulation of the output (stabilized) voltage,

an operation has been introduced - suppression of noise of the reference voltage (noise of the output voltage of the ION).

Brief description of the drawings

Figure 1 shows the timing diagram and spectrogram of the noise component of the ION (IMS SPX385-2.5).

.Figure 2 shows the timing diagram and spectrogram of the noise component of the noise voltage at the output of the stabilizer when

.

.Figure 3 shows the timing diagram and spectrogram of the noise component of the noise voltage at the output of the stabilizer when

.

Figure 4 shows a variant of the functional diagram of a device for implementing a method for reducing the noise level of a compensation constant voltage stabilizer with continuous regulation and a transistor UPT.

Figure 5 shows a variant of the functional diagram of the device implementation on transistors of the method for reducing the noise level of a compensation constant voltage stabilizer with continuous regulation and UPT on the OS.

=0,38 мкВ (пик-пик) в полосе частот 0.1÷10 Гц); С1 - 33 нФ; R1÷R4 - 51 кОм). Figure 6 shows the timing diagram and spectrogram of the noise component at the output of the PN block, implemented using: DA1, DA2 - OA OP07C (

\u003d 0.38 μV (peak-peak) in the frequency band 0.1 ÷ 10 Hz); C1 - 33 nF; R1÷R4 - 51 kOhm).

.Figure 7 shows a timing diagram and a spectrogram of the noise component of the noise voltage at the output of the stabilizer with the PN unit at

.

Implementation of the invention

The essence of the proposed method is to perform the following operations:

1) formation of feedback voltage;

2) formation of the reference voltage;

3) noise suppression of the reference voltage;

3) mismatch voltage formation;

4) amplification of the mismatch voltage;

5) regulation of the output (stabilized) voltage.

A device for implementing a method for reducing the noise level of a compensation DC voltage stabilizer with continuous regulation of figure 4 (figure 5), contains: a noise suppressor (PN) 1 - an isolation capacitor 2, a voltage follower (PN) 3, a subtractor 5; control element 11 - transistor 13, resistor 12; resistive voltage divider 14 - resistors 15, 16; ION 17 - resistor 18, zener diode 19; load resistance 20; UPT 21 - resistor 22, transistor 23, (OU 22, Fig.5), and the collector of the transistor 13 is connected to the first terminal of the resistor 12 and the positive polarity input of the device, and the emitter to the first terminals of the resistors 15, 18 and through the load resistance 20 to the anode zener diode 19, the second output of the resistor 16 and the negative polarity input of the device; the second terminal of the resistor 15 is connected to the first terminal of the resistor 16 and the base of the transistor 23 (non-inverting input of the op-amp 22, figure 5), the collector of the transistor 23 (the output of the op-amp 22, figure 5) is connected to the second terminal of the resistor 12 and the base of the transistor 13; the second terminal of the resistor 18 is connected to the cathode of the zener diode 19 and the input of the PS 1, the output of which is connected to the emitter of the transistor 23 and through the resistor 22 to the emitter of the transistor 13 (non-inverting input of the op-amp 22, Fig.5); the input PS 1 is connected to the first input of the subtractor 5 and through series-connected separating capacitor 2 and PS 3, to the second input of the subtractor 5, the output of which serves as the output PS 1.

PN 3 contains op-amp 4, and the non-inverting input of op-amp 4 serves as the input of the voltage follower, and the inverting input connected to the output of op-amp 4 serves as the output of PN 3.

Subtractor 5 contains op-amp 6 and resistors 7÷10, the first output of resistor 7 is the first input of subtractor 5, and the second output is connected to the non-inverting input of op-amp 6 and the first output of resistor 8, the second output of which is grounded; the first output of the resistor 9 serves as the second input of the subtractor 5, and the second output is connected to the inverting input of the op-amp 6 and the first output of the resistor 10, the second output of which is connected to the output of the op-amp 6 and the output of the subtractor 5.

A device for implementing a method for reducing the noise level of a compensation DC voltage stabilizer with continuous regulation operates as follows.

Assume that the voltage U _in at the input of the stabilizer has increased, then the voltage U _out at the output of the stabilizer should increase, as well as the voltage U _OS coming to the input of the UPT 21 (the base of the transistor 23, Fig. 4; the inverting input of the OU 22, Fig. 5), which, in turn, will lead to the locking of the transistor 13. The current of the transistor 13 will decrease and the voltage U _out at the load resistance 20 will drop almost to the original value.

Assume that the voltage U _in at the input of the stabilizer has decreased, then the voltage U _out at the output of the stabilizer should decrease, as well as the voltage U _OS coming to the input of the UPT 21 (the base of the transistor 23, Fig. 4; the inverting input of the OU 22, Fig. 5), which, in turn, will lead to transistor 13. The current of transistor 13 will increase and the voltage U _out at load resistance 20 will increase almost to its original value.

,

, определяются соотношениями:As in the case of the prototype, the output noise level of the stabilizer, the stabilization and smoothing coefficients are determined by the noise level at the emitter of the transistor 23, figure 4 (non-inverting input of the op-amp 22, figure 5) and, subject to the assumptions that

,

, are determined by the relations:

- in the case of the implementation of the UPT 21 based on the transistor 23, Fig.4

(9)

(nine)

, (10)

, (10)

)- in the case of the implementation of UPT 21 based on OS 22, figure 5, (because

)

(11)

(eleven)

, (12)

, (12)

- напряжение шумов на выходе блока ПШ 1.where

- noise voltage at the output of the block PS 1.

PS 1 works as follows.

, выделяемую из выходного сигнала с помощью конденсатора 2 и поступающую на вход ПН 1.The output signal of ION 17 contains a noise component

, extracted from the output signal with the help of capacitor 2 and fed to the input of PN 1.

Since PN 1 is made according to the scheme of a non-inverting amplifier with 100% feedback, it is characterized by the following parameters:

, (13)

, (13)

where R _{in. OU} , R out. _OU , K _OU - input (differential), output impedance and gain of OU 4;

R _in.pn , R _out.pn , K _pn - input, output resistance and gain (transmission) PN 1.

In general, the following condition is satisfied:

(14)

(fourteen)

- выходное сопротивление ИОН 17.where

- output impedance of ION 17.

The selected noise component, from the output of PN 1, and the output signal of ION 17 are fed to the inputs of the subtractor 5, which compensates (suppresses) the noise component.

цепи ПН 1 образованной конденсатором 2 и входным сопротивлением R_вх.пн ПН 1, являющейся, по сути, RC-фильтром высоких частот. Что обеспечивает фазовый сдвиг шумовой составляющей

, в соответствии с выражением (15)The degree of suppression of the noise component is largely determined by the time constant

circuit PN 1 formed by capacitor 2 and input impedance R _in.pn PN 1, which is, in fact, an RC high-pass filter. What provides the phase shift of the noise component

, according to expression (15)

, (15)

, (15)

, (16)where

, (16)

- емкость конденсатора 2;where

- capacitance of the capacitor 2;

постоянная времени фильтра высоких частот ПШ 1,

high-pass filter time constant PS 1,

and time constant of the ION 17 circuit

(17)

(17)

накладываются условия:At the same time, on

conditions apply:

(18)

(eighteen)

The condition is imposed on the resistances of resistors 7÷10 of subtractor 5

(19)

(19)

- 1

4 резисторы (элементы 7÷10) вычитателя 5.where

- one

4 resistors (elements 7÷10) of subtractor 5.

- среднеквадратичное напряжение шума на выходе ПШ 1.As a feature of the circuit implementation of PN 1, it should be noted the unit transmission coefficients of PN 3 and subtractor 5, as well as the uncorrelatedness of their noise voltages, which, against the background of uncorrelatedness with the noise of ION 17, determines

- RMS noise voltage at the output of PS 1.

, (20)

, (twenty)

- коэффициент подавления шума ПШ; where

- PN noise suppression factor;

- напряжение шума пик-пик

ИОН 17;

- peak-to-peak noise voltage

ION 17;

,

- напряжение шума пик-пик (

) ОУ 4, 6.

,

- peak-to-peak noise voltage (

) OS 4, 6.

=0,38 мкВ пик-пик в полосе частот 0.1÷10 Гц); конденсатора 2 - С1 = 33 нФ; резисторов 7÷10 - R1-R4 = 51 кОм), (напряжение шума пик-пик

= 0,54 мкВ).Figure 6 shows the timing diagram and the spectrogram of the noise component at the output of the block PS 1, implemented using: OS 4, 6 - OS OP07S (

\u003d 0.38 μV peak-peak in the frequency band 0.1 ÷ 10 Hz); capacitor 2 - C1 = 33 nF; resistors 7÷10 - R1-R4 = 51 kOhm), (noise voltage peak-peak

= 0.54 μV).

(напряжение шума пик-пик

= 2,3 мкВ, при существенном снижении уровня высокочастотных гармоник).Figure 7 shows a timing diagram and a spectrogram of the noise component of the noise voltage at the output of the stabilizer with the PN unit at

(noise voltage peak-peak

= 2.3 μV, with a significant reduction in the level of high-frequency harmonics).

.A change in _{ΔU in} by ±10% of U _in led to a change in ΔU _out by 0.059% at

.

The developed method for reducing the noise level of a compensation DC voltage stabilizer with continuous regulation provides a decrease in the level of output noise while increasing the stability of the automatic control system, and therefore provides a potential opportunity to increase the stabilization and smoothing coefficients.

Claims (1)

A method for reducing the noise level of a compensation DC voltage stabilizer with continuous regulation, including the operations of generating a feedback voltage, generating a reference voltage, generating a mismatch voltage, amplifying the mismatch voltage, regulating the output voltage, characterized in that the operation of suppressing the noise of the reference voltage is introduced.

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