RU2755496C1 - Pulse voltage stabilizer - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: invention relates to the field of electrical engineering, in particular to pulse voltage stabilizers. A pulse voltage stabilizer contains an input bus, a key element, a filter, a comparison circuit, a control circuit, an output bus, and a common bus. The key element contains a resistor, a diode, the first MIS transistor with an induced n-type channel, the second MIS transistor with an induced n-type channel, a capacitor. The filter contains a diode and a capacitor. The comparison circuit contains the first resistor, a p-n-p-type transistor, the first stabilitron, the second stabilitron, the second resistor. The control circuit contains a pulse generator of the initial installation, an element 2-OR with an open drain, a single-vibrator.

EFFECT: expansion of functionality.

1 cl, 2 dwg

Description

The technical field to which the invention relates

The invention relates to the field of electrical engineering, in particular to pulse voltage stabilizers.

State of the art

Known parametric DC voltage regulator containing a reference zener diode, a transistor and a resistor. The input bus of the voltage regulator is connected directly to the collector of the transistor and through a resistor to the cathode of the reference zener diode. The anode of the reference zener diode is connected to a common bus. The base of the transistor is connected to the cathode of the reference zener diode. The emitter of the transistor is connected to the output bus of the voltage stabilizer (Veresov G.P., Smuryakov Yu.L. Stabilized power supplies of radio equipment. - M .: Energiya, 1978. S. 53, Fig. 2-8b).

The disadvantage of the specified voltage stabilizer is the low efficiency (efficiency) associated with large energy losses in the circuits of the transistor and the reference zener diode, increasing with increasing supply voltage.

Known switching voltage regulator containing the bus of the initial installation, the input bus, the key element, the filter, the comparison circuit, the control circuit, the output bus. The key element contains the first PNP transistor, the second NPN transistor, the first and second resistors. The filter contains a diode and a capacitor. The comparison circuit contains a pnp-type transistor, a zener diode, a diode, first and second resistors. The control circuit contains a pulse generator, an RS trigger, an open drain inverter (patent RU No. 2216765, IPC G05F 1/56).

The disadvantage of this device is limited functionality due to:

- low temperature stability of the output voltage (narrow range of operating temperatures) in the case of a wide range of output voltages;

- narrow range of output voltages at high temperature stability (wide range of operating temperatures);

- low efficiency, due to the implementation of a key element based on bipolar transistors, current-controlled devices, whose own energy consumption, and hence the thermal regime, is directly related to the value of the switched current;

- low accuracy of setting the output voltage;

- lack of overload protection.

The closest analogue - a prototype to the claimed technical solution is a pulse voltage regulator (patent RU No. 154069, IPC G05F 1/56).

The switching voltage regulator contains an input bus, a key element, a filter, a comparison circuit, a control circuit, an output bus, a common bus, and an initial setting bus. The key element contains the first resistor, the second resistor, the first pnp-type transistor, the second n-pn-type transistor, the filter contains a diode and a capacitor. The comparison circuit contains a first resistor, a diode, a pnp-type transistor, a first zener diode, a second zener diode, and a second resistor. The control circuit contains a pulse generator, an RS flip-flop, an open-drain inverter. The input bus is connected to the input of the key element, which through the first resistor is connected to the base of the second transistor, the collector of the first transistor, the output of the control circuit and to the cathode of the diode of the comparison circuit, and through the second resistor is connected to the emitter of the first transistor, the base of which is connected to the collector of the second transistor, which is the output of the key element, and connected to the input of the comparison circuit and to the input of the filter. The input of the comparison circuit is connected directly to the emitter of the transistor and through the first resistor, connected to the anode of the diode, the base of the transistor, the cathode of the first zener diode, the anode of which, through the oppositely connected second zener diode, is connected to the common bus of the device, and the collector of the transistor, which is the output of the comparison circuit, through the second resistor is connected to the common bus. The filter input is connected to the anode of the diode, the cathode of which is directly connected to the output bus and through a capacitor is connected to the common bus. The output of the comparison circuit is connected to the S-input of the RS-flip-flop, the first R-input of which is connected to the output of the generator, the second R-input of the RS-flip-flop is connected to the initial setting bus. The direct output of the RS flip-flop, through an open-drain inverter, is connected to the output of the control circuit.

The disadvantage of this device is limited functionality due to:

- low efficiency, due to the implementation of a key element based on bipolar transistors, current-controlled devices, whose own energy consumption, and hence the thermal regime, is directly related to the value of the switched current;

- low accuracy of setting the output voltage;

- lack of overload protection.

Disclosure of invention

The technical result that can be achieved with the proposed invention is reduced to expanding the functionality.

The technical result is achieved by the fact that a pulse voltage regulator contains: an input bus; output bus; common bus; a key element containing a resistor; a filter containing a diode and a capacitor; a comparison circuit containing a pnp-type transistor, first and second zener diodes, first and second resistors; control scheme; moreover, the input bus is connected to the input of the key element, the output of which is connected to the inputs of the filter and the comparison circuit, the output of which is connected to the input of the control circuit, the output of which is connected to the control input of the key element; the input of the comparison circuit is connected directly to the emitter of the p-n-p-type transistor and through the first resistor, connected to the base of the p-n-p-type transistor, the cathode of the first zener diode, the anode of which, through the oppositely connected second zener diode, is connected to the common bus, and the collector of the pnp-type transistor, which is the output of the comparison circuit, through the second resistor, is connected to the common bus; the filter input is connected to the anode of the diode, the cathode of which is directly connected to the output bus and through a capacitor is connected to the common bus; introduced: into the control circuit - an initial setup pulse shaper; 2-OR element with open drain, one-shot, and the first input of the 2-OR element with open drain, the output of which serves as the output of the control circuit, is connected to the output of the initial setup pulse shaper, and the second input is connected to the output of the one-shot, the input of which serves as the input of the control circuit ; the key element consists of a diode, the first and second MOS transistors with an induced n-type channel, a capacitor, and the anode of the diode and the drain of the first MOS transistor with an induced n-type channel serve as the input of the key element, the cathode of the diode is connected to the first terminals of the resistor and capacitor, the second terminal of which and the source of the first MOS transistor with an induced n-type channel are connected to the output of the key element, the second terminal of the resistor and the gate of the first MOS transistor with an induced n-type channel are connected to the drain of the second MOS transistor with an induced n-type channel, the gate of which is connected with the control input of the key element, and the source - with the common bus.

Brief Description of Drawings

FIG. 1 shows a functional diagram of a switching voltage regulator.

FIG. 2 shows the timing diagrams of the operation of the switching voltage regulator:

- fig. 2.a - timing diagrams at the output of the pulse former 20 of the initial installation;

- fig. 2.b - timing diagrams at the output of the element 2-OR 21 with an open drain;

- fig. 2.c - timing diagrams at the output of the one-shot 22;

- fig. 2.d - timing diagrams at the output of the comparison circuit 4 (resistor 19);

- fig. 2.e - timing diagrams on the output bus 6 (capacitor 14).

Implementation of the invention

The switching voltage regulator (Fig. 1) contains an input bus 1, a key element 2, a filter 3, a comparison circuit 4, a control circuit 5, an output bus 6, a common bus 7.

The key element 2 contains a resistor 8, a diode 9, a first MOS transistor 10 with an induced n-type channel, a second MOS transistor 11 with an induced n-type channel, a capacitor 12.

Filter 3 contains a diode 13 and a capacitor 14.

Comparison circuit 4 contains a first resistor 15, a pnp transistor 16, a first zener diode 17, a second zener diode 18, a second resistor 19.

The control circuit 5 comprises an initial setting pulse shaper 20; element 2-OR 21 with open drain, one-shot 22.

The input bus 1 is connected to the input of the key element 2, the output of which is connected to the inputs of the comparison circuit 4 and the filter 3. The output of the comparison circuit 4 is connected to the input of the control circuit 5, the output of which is connected to the control input of the key element 2.

The input of the key element 2 is connected to the anode of the diode 9 and the drain of the first MIS transistor 10 with an induced n-type channel, the cathode of the diode 9 is connected to the first terminals of the resistor 8 and the capacitor 12, the second terminal of which and the source of the first MOS transistor 10 with an induced n-type channel connected to the output of the key element 2, the second terminal of the resistor 8 and the gate of the first MIS transistor 10 with an induced n-type channel are connected to the drain of the second MOS transistor 11 with an induced n-type channel, the gate of which is connected to the control input of the key element 2, and the source is with common bus 7.

The input of the comparison circuit 4 is connected directly to the emitter of the p-n-p-type transistor 16 and through the first resistor 15, is connected to the base of the p-n-p-type transistor 16, the cathode of the first zener diode 17, the anode of which, through the oppositely connected second zener diode 18 , is connected to the common bus 7 of the device, and the collector of the pnp-type transistor 16, which is the output of the comparison circuit 4, through the second resistor 19 is connected to the common bus 7.

The filter input 3 is connected to the anode of the diode 13, the cathode of which is directly connected to the output bus 6 and through the capacitor 14 is connected to the common bus 7.

The input of the control circuit 5 is connected to the output of the one-shot 22, the output of which is connected to the second input of the 2-OR element with an open drain, the output of which serves as the output of the control circuit 5, and the input is connected to the output of the pulse shaper 20 of the initial setting.

As a pulse shaper 20 of the initial setup, a Schmitt trigger can be used, which generates a positive pulse when the power is turned on (https://stadopedia.su/9_5389_primenenie-logicheskih-elementov.html, Fig. 2-38).

As a one-shot 22, a waiting multivibrator can be used, which is converted into an unstable state with a high voltage level at the output when a high voltage level is applied to the input (https://vpayaem.ru/informationl 8.html, Fig. 9).

Switching voltage regulator works as follows.

At the time of applying a constant supply voltage to the input bus 1 and to the blocks of the control circuit 5 (the power circuits of the latter are not shown), the key element 2 is closed, there is no voltage on the output bus 6, at the output of the comparison circuit 4 and the input of the control circuit 5 (at the input of the one-shot 22) - low potential. At the same time, when the supply voltage is applied, the output signal of the pulse shaper 20 of the initial setting (Fig.2a), (regardless of the state of the one-shot 22 (transient processes at the moment of switching on, (Fig.2c))) by means of the 2-OR element 21 with an open drain (Fig.2.b), ensures that the output of the control circuit 5 is maintained for a fixed time interval [t ₀ ; t ₂ ], high potential (level "log.1"), ensuring the maintenance of the MOS transistor 11 with an induced n-type channel in the open state, and the MOS transistor 10 with an induced n-type channel in the closed state, since at the gate of the MOS transistor 10 with an induced n-channel, the potential remains close to the ground potential. Due to the closed state of the MIS transistor 10 with an induced n-type channel, the capacitor 12 is charged to a voltage close to the voltage of the power source, minus the voltage drop across the diode 9 and the load of the key element 2.

By the time t ₁ , the transients in the one-shot 22 are completed. One-vibrator 22 goes into a steady state, the output is set to the level "log.0".

From the moment of time t ₂ , at the output of the pulse shaper 20 of the initial setting, the level "log.0" is set, and at the output of the OR element 21 with an open drain (at the output of the control circuit 5), a potential is set close to the ground potential, which translates the MIS transistor 11 with an induced n-type channel to the closed state. This leads to an increase in the voltage at the gate of the MIS transistor 10 with an induced n-type channel to the supply voltage minus the voltage drop across the diode 9. The subsequent increase in the voltage at the source of the MOS transistor 10 with an induced n-type channel is transmitted to its gate through the capacitor 12, since diode 9 is turned off, MIS transistor 10 with an induced n-type channel is turned on. In the general case, maintaining the MOS transistor 10 with an induced channel n-type in the open state is provided by the charge of the capacitor 12.

The opening of the MIS transistor 10 with an induced n-type channel is accompanied by the charge of the capacitor 14 (Fig.2e) and an increase in the voltage at the emitter of the transistor 16. However, the base current of the transistor 16 is absent, since the Zener diode 17 has a high resistance (the Zener diode 18 is open), the transistor 16 closed; at the output of the comparison circuit 4 (resistor 19, Fig. 2.d) - a potential close to zero. When the voltage at the input of the comparison circuit 4 reaches the breakdown (opening) of the zener diode 17, the transistor 16 opens. At the output of the comparison circuit 4, a high potential appears (time t ₃ , Fig. 2.e), leading to an unstable state of the one-shot 22 At the output of the control circuit 5, during a fixed time interval [t ₃ ; t ₄ ] (Fig. 2.b), a high potential is maintained (level "log.1"), which ensures that the key element 2 is locked and the capacitor 12 is recharged.

In the time interval [t ₃ ; t ₄ ] power supply of the load of the switching voltage regulator is carried out due to the energy stored in the capacitor 14.

Resistor 15 binds the potential of the base of the transistor 16 to the potential of its emitter. Resistor 19 is the collector load of the transistor 16. Zener diodes 17 and 18 are of the same type, avalanche, provide mutual compensation of temperature coefficients of the stabilization voltage, and hence the expansion of the operating temperature range of the device.

At the moment of time t _{4, the one-} shot 22 goes into a stable state, the output is set to the level "log.0", which ensures the transfer of the key element 2 to the open state and the recharging of the capacitor 14.

In the future, the algorithm of the stabilizer is repeated. Moreover, due to the rigid feedback of the duration of the steady state of the one-shot 22 (the repetition period of the control pulses) with the charging rate of the capacitor 14 (load resistance of the stabilizer, jump-like voltage fluctuations on the input bus 1), the proposed device is characterized by:

- higher accuracy of setting the output voltage in comparison with the prototype, since, in the case of the prototype, both the instability of the load resistance and abrupt fluctuations of the voltage on the input bus do not affect the repetition period of the control pulses;

- the presence of current protection.

In the event of an overcurrent (a significant decrease in the load resistance, up to a short circuit), the Zener diode 17, and hence the key element 2, will remain closed.

In the case of the prototype, current protection is not provided - the key element is switched to the open state regardless of the load resistance, which significantly reduces the reliability of the device.

In addition, in the case of the prototype, there is a relatively low efficiency. This is due to the implementation of the key element circuit based on bipolar transistors. Bipolar transistors are current-controlled devices, whose own power consumption, and hence the thermal regime, is directly related to the magnitude of the switched current. And an attempt to reduce transistors' own energy consumption (to increase the efficiency of the device) by using transistors with a lower base current (and hence a lower allowable dissipation power - will inevitably increase the requirements for an increase in heat dissipation), will entail a decrease in the reliability of the device.

At the same time, MIS transistors with an induced channel are characterized by a number of advantages over bipolar transistors (Oksner E.S. Powerful field-effect transistors and their application. - M .: Radio i svyaz, 1985, p. 19):

- voltage control (high resistance on the side of the gate, the gate current is practically zero);

- high switching speed;

- almost unlimited output load capacity (if the switching speed is not taken into account);

- very low probability of thermal self-heating;

- very low probability of secondary breakdown;

- the admissibility of a sharp change in the drain current.

This means that the proposed device, in the circuit of key element 2 of which MIS transistors are used, with the same switching power as in the case of the prototype, will be characterized by a higher value of both efficiency and reliability. Moreover, in the case of a prototype, as part of the key element circuit, it is necessary to use two bipolar transistors of the same type (for example, high power), and in the proposed device - different types (for example, high power - MIS transistor 10 and low power - MIS transistor 11).

In general, the proposed device has wider functionality in comparison with the prototype.

Claims (1)

A switching voltage regulator containing an input bus, an output bus, a common bus, a key element containing a resistor, a filter containing a diode and a capacitor, in addition, a comparison circuit containing a pnp-type transistor, the first and second zener diodes, the first and the second resistors, in addition, a control circuit, and the input bus is connected to the input of the key element, the output of which is connected to the inputs of the filter and the comparison circuit, the output of which is connected to the input of the control circuit, the output of which is connected to the control input of the key element; the input of the comparison circuit is connected directly to the emitter of the p-n-p-type transistor and through the first resistor is connected to the base of the p-n-p-type transistor, the cathode of the first zener diode, the anode of which is connected through the oppositely connected second zener diode to the common bus, and the collector of the transistor pnp-type, which is the output of the comparison circuit, through the second resistor is connected to the common bus; the filter input is connected to the anode of the diode, the cathode of which is directly connected to the output bus and through a capacitor is connected to the common bus; characterized in that the following are introduced: into the control circuit - an initial setup pulse shaper; 2-OR element with open drain, one-shot, and the first input of the 2-OR element with open drain, the output of which serves as the output of the control circuit, is connected to the output of the initial setup pulse shaper, and the second input is connected to the output of the one-shot, the input of which serves as the input of the control circuit ; the key element includes a diode, the first and second MIS transistors with an induced n-type channel, a capacitor, and the anode of the diode and the drain of the first MOS transistor with an induced n-type channel serve as the input of the key element, the cathode of the diode is connected to the first terminals of the resistor and capacitor, the second terminal of which and the source of the first MOS transistor with an induced n-type channel are connected to the output of the key element, the second terminal of the resistor and the gate of the first MOS transistor with an induced n-type channel are connected to the drain of the second MOS transistor with an induced n-type channel, the gate of which is connected with the control input of the key element, and the source - with the common bus.

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