阅读说明：本技术 一种多路输出恒压电路和稳压电源 (Multi-output constant voltage circuit and voltage-stabilized power supply ) 是由 白壮 钟柯佳 于 2019-10-09 设计创作，主要内容包括：本发明属于电路设计领域,提供了一种多路输出恒压电路和稳压电源。该多路输出恒压电路包括多个恒压输出电路；在多路输出恒压电路中,串联设置有多个稳压管,限流电阻与多个稳压管串联连接；多个恒压输出电路分别设置在多个稳压管的输入端,从而通过多个稳压管实现多个恒压电路的输出；与多个恒压输出电路并联设置有输入滤波电容；每个恒压输出电路均分别并联设置有输出滤波电容。本发明提供的多路输出恒压电路和稳压电源可以得到任意的输出电压值,成本较低,使用的元器件数量少,电路的可靠性高。(The invention belongs to the field of circuit design and provides a multi-output constant voltage circuit and a voltage-stabilized power supply. The multi-output constant voltage circuit comprises a plurality of constant voltage output circuits; in the multi-output constant voltage circuit, a plurality of voltage-stabilizing tubes are arranged in series, and a current-limiting resistor is connected with the plurality of voltage-stabilizing tubes in series; the constant voltage output circuits are respectively arranged at the input ends of the voltage stabilizing tubes, so that the output of the constant voltage circuits is realized through the voltage stabilizing tubes; an input filter capacitor is connected in parallel with the constant voltage output circuits; and each constant voltage output circuit is respectively provided with an output filter capacitor in parallel. The multi-output constant voltage circuit and the voltage-stabilized power supply provided by the invention can obtain any output voltage value, and have the advantages of low cost, small number of used components and high reliability of the circuit.)

1. A multi-output constant voltage circuit is characterized in that the multi-output constant voltage circuit comprises a plurality of constant voltage output circuits; in the multi-output constant voltage circuit, a plurality of voltage stabilizing tubes are arranged in series, and a current limiting resistor is connected with the plurality of voltage stabilizing tubes in series; the constant voltage output circuits are respectively arranged at the input ends of the voltage stabilizing tubes, so that the output of the constant voltage circuits is realized through the voltage stabilizing tubes; an input filter capacitor is connected in parallel with the constant voltage output circuits; and each constant voltage output circuit is respectively provided with an output filter capacitor in parallel.

2. The multi-output constant voltage circuit of claim 1, wherein:

the current-limiting resistor is arranged at one side of the input end close to the whole multi-output constant voltage circuit.

3. The multi-output constant voltage circuit according to claim 1 or 2, wherein:

and each output circuit of the multi-output constant voltage circuit is provided with an adjusting tube respectively.

4. The multi-output constant voltage circuit of claim 3, wherein:

the adjusting tube is a triode; the base electrode of the triode is connected with the input end of the voltage stabilizing tube, the collector electrode of the triode is connected with the input end of the whole multi-output constant voltage circuit, and the emitter electrode of the triode is connected with the output ends of the constant voltage output circuits.

5. The multi-output constant voltage circuit of claim 4, wherein:

a temperature compensation component is also arranged on the multi-output constant-voltage circuit;

preferably, the temperature compensation component is a diode, and the diode is connected in series with the current limiting resistor and the plurality of voltage stabilizing tubes.

6. A multi-output constant voltage circuit is characterized in that the multi-output constant voltage circuit comprises a plurality of constant voltage output circuits; in the multi-output constant voltage circuit, a plurality of voltage stabilizing tubes are arranged in series, and a current limiting resistor is connected with the plurality of voltage stabilizing tubes in series; an input filter capacitor is connected in parallel with the constant voltage output circuits; each constant voltage output circuit is respectively provided with an output filter capacitor in parallel;

for each output circuit, the collector of the adjusting tube is connected with the input end of the whole multi-output constant voltage circuit, the emitter is connected with the output end of the constant voltage output circuit, and the base is respectively connected with the collector of the amplifying tube and the resistor used as the collector resistor of the amplifying tube;

the collector of the amplifying tube is respectively connected with the base of the adjusting tube and the resistor used as the collector resistor of the amplifying tube, the emitter is connected with the input end of the voltage stabilizing tube, and the base is connected with the connecting wire of the two output sampling resistors;

one end of a resistor used as a collector resistor of the amplifying tube is connected with the input end of the whole multi-output constant voltage circuit, and the other end of the resistor is connected with a collector of the amplifying tube;

two output sampling resistors are connected in series, and a series circuit formed by the two output sampling resistors is connected in parallel with the output circuit.

7. The multi-output constant voltage circuit of claim 6, wherein:

the current-limiting resistor is arranged at one side of the input end close to the whole multi-output constant voltage circuit.

8. The multi-output constant voltage circuit according to claim 6 or 7, wherein:

a temperature compensation component is also arranged on the multi-output constant-voltage circuit;

the temperature compensation component is a diode, and the diode is connected with the current-limiting resistor and the voltage-stabilizing tubes in series.

9. The multi-output constant voltage circuit according to any one of claims 1 to 8, wherein:

replacing the current limiting resistor with a constant current source circuit;

preferably, the constant current source circuit is provided with a triode, an emitting electrode of the triode is connected with an output end of the current-limiting resistor, a collector electrode of the triode is connected with an input end of a voltage-stabilizing tube close to an input end of the whole multi-output constant voltage circuit, and a base electrode of the triode is connected with a connecting line of the voltage-stabilizing tube of the constant current source circuit and the resistor of the constant current source circuit; the voltage-stabilizing tube of the constant current source circuit and the resistor of the constant current source circuit are connected in series to form a series circuit, and the series circuit is connected with the constant voltage output circuits in parallel.

10. A regulated power supply comprising a multiple output constant voltage circuit according to any one of claims 1-9.

Technical Field

The invention belongs to the field of circuit design, and particularly relates to a multi-output constant voltage circuit and a voltage-stabilized power supply.

Background

In the existing embedded industry, sometimes a plurality of power supplies with different voltage values are often needed to supply power on one control circuit board, and the existing solution is realized by adding a plurality of linear voltage reduction modules on the basis of inputting a power supply. For example, as shown in fig. 1, wherein a plurality of linear buck modules are connected in parallel. In some cases, in order to reduce the power consumption of the linear buck module with low voltage output, a plurality of linear buck modules may be connected in series, as shown in fig. 2, in which the output voltage of the linear buck module 1 is higher than the output voltage of the linear buck module 2, the output voltage of the linear buck module 2 is higher than the output voltage of the linear buck module 3, and so on.

In addition, the connection modes of the linear voltage reduction modules in fig. 1 and fig. 2 can be combined for use. Another solution is to use a multi-output switching power supply, and connect a linear voltage-reducing module to the output, which has already been applied for patent, and the name of the patent is "a multi-output hybrid power supply module", corresponding to chinese patent application No. 201910231447.2. The disadvantages of these multiple output circuit schemes are:

1. only a few relatively fixed voltages can be output. For example, the AMS1117 series buck chip can only output voltages of 1.25V, 1.5V, 1.8V, 2.5V, 2.85V, 3.3V and 5V, but the AMS1117 series buck chip cannot output other voltages such as 8V.

2. The cost is high. For some embedded control circuits, the power required by the load is very small, about hundreds of mW-1W can be used enough, the maximum output power of the general linear voltage reduction module reaches several watts, and resources are wasted. And the scheme of adopting the switching power supply and the linear voltage reduction module has higher cost and larger volume if being used in occasions without isolation.

Disclosure of Invention

In order to solve the above problems in the prior art, the present invention provides a multi-output constant voltage circuit and a regulated power supply including the same.

The invention provides a multi-output constant voltage circuit, which is characterized by comprising a plurality of constant voltage output circuits; in the multi-output constant voltage circuit, a plurality of voltage stabilizing tubes are arranged in series, and a current limiting resistor is connected with the plurality of voltage stabilizing tubes in series; the constant voltage output circuits are respectively arranged at the input ends of the voltage stabilizing tubes, so that the output of the constant voltage circuits is realized through the voltage stabilizing tubes; an input filter capacitor is connected in parallel with the constant voltage output circuits; and each constant voltage output circuit is respectively provided with an output filter capacitor in parallel.

In a preferred embodiment, the current limiting resistor is disposed on a side close to an input terminal of the entire multi-output constant voltage circuit.

In a preferred embodiment, a regulating tube is respectively arranged on each output circuit of the multi-output constant voltage circuit.

In a preferred embodiment, the adjusting tube is a triode; the base electrode of the triode is connected with the input end of the voltage stabilizing tube, the collector electrode of the triode is connected with the input end of the whole multi-output constant voltage circuit, and the emitter electrode of the triode is connected with the output ends of the constant voltage output circuits.

In a preferred embodiment, a temperature compensation component is further disposed on the multi-output constant-voltage circuit;

preferably, the temperature compensation component is a diode, and the diode is connected in series with the current limiting resistor and the plurality of voltage stabilizing tubes.

In a preferred embodiment, the multi-output constant voltage circuit includes a plurality of constant voltage output circuits; in the multi-output constant voltage circuit, a plurality of voltage stabilizing tubes are arranged in series, and a current limiting resistor is connected with the plurality of voltage stabilizing tubes in series; an input filter capacitor is connected in parallel with the constant voltage output circuits; each constant voltage output circuit is respectively provided with an output filter capacitor in parallel;

for each output circuit, the collector of the adjusting tube is connected with the input end of the whole multi-output constant voltage circuit, the emitter is connected with the output end of the constant voltage output circuit, and the base is respectively connected with the collector of the amplifying tube and the resistor used as the collector resistor of the amplifying tube;

the collector of the amplifying tube is respectively connected with the base of the adjusting tube and the resistor used as the collector resistor of the amplifying tube, the emitter is connected with the input end of the voltage stabilizing tube, and the base is connected with the connecting wire of the two output sampling resistors;

one end of a resistor used as a collector resistor of the amplifying tube is connected with the input end of the whole multi-output constant voltage circuit, and the other end of the resistor is connected with a collector of the amplifying tube;

two output sampling resistors are connected in series, and a series circuit formed by the two output sampling resistors is connected in parallel with the output circuit.

In a preferred embodiment, the current limiting resistor is disposed on a side close to an input terminal of the entire multi-output constant voltage circuit.

In a preferred embodiment, a temperature compensation component is further disposed on the multi-output constant-voltage circuit;

the temperature compensation component is a diode, and the diode is connected with the current-limiting resistor and the voltage-stabilizing tubes in series.

In a preferred embodiment, the current limiting resistor is replaced by a constant current source circuit;

preferably, the constant current source circuit is provided with a triode, an emitting electrode of the triode is connected with an output end of the current-limiting resistor, a collector electrode of the triode is connected with an input end of a voltage-stabilizing tube close to an input end of the whole multi-output constant voltage circuit, and a base electrode of the triode is connected with a connecting line of the voltage-stabilizing tube of the constant current source circuit and the resistor of the constant current source circuit; the voltage-stabilizing tube of the constant current source circuit and the resistor of the constant current source circuit are connected in series to form a series circuit, and the series circuit is connected with the constant voltage output circuits in parallel.

The invention also provides a stabilized voltage power supply which comprises any one of the multi-output constant voltage circuits.

The multi-output constant voltage circuit and the voltage-stabilized power supply adopting the same can conveniently and quickly obtain any output voltage value, and are low in cost. Meanwhile, the reliability of the circuit is high due to the fact that the number of used components is small.

Drawings

Fig. 1 is a prior art multi-output circuit in which a plurality of linear voltage-reducing modules are connected in parallel.

Fig. 2 is a prior art multi-output circuit in which a plurality of linear voltage-reducing modules are connected in series.

Fig. 3 is a schematic diagram of a multi-output constant voltage circuit according to a preferred embodiment of the present invention.

Fig. 4 is a schematic diagram of a multi-output constant voltage circuit according to another preferred embodiment of the present invention.

Fig. 5 is a schematic diagram of a multi-output constant voltage circuit according to another preferred embodiment of the present invention.

Fig. 6 is a schematic diagram of a multi-output constant voltage circuit according to another preferred embodiment of the present invention.

Fig. 7 is a schematic diagram of a configuration of a multi-output constant voltage circuit in which a constant current source circuit is used instead of a current limiting resistor on the basis of the multi-output constant voltage circuit shown in fig. 6.

Detailed Description

In order to make the technical solution, objects and advantages of the present invention clearer, the present invention is further described in detail by the following specific embodiments. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. For the electrical and communication fields, either a wired connection or a wireless connection is possible. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Referring to fig. 3, an embodiment of the present invention provides a multi-output constant voltage circuit. The multi-output constant voltage circuit includes a plurality of constant voltage output circuits (three output circuits Vo1, Vo2, Vo3 are shown in fig. 3). In the multi-output constant voltage circuit, a plurality of voltage-stabilizing tubes (three voltage-stabilizing tubes Z1, Z2 and Z3 which are connected in series are shown in figure 3), a current-limiting resistor R1 is connected with the plurality of voltage-stabilizing tubes in series and is arranged at one side close to the input end Vin of the whole multi-output constant voltage circuit; the plurality of constant voltage output circuits are respectively arranged at the input ends of the plurality of voltage stabilizing tubes (one end of the input end Vin close to the whole multi-output constant voltage circuit is defined as the input end, the same below), so that the output of the plurality of constant voltage circuits is realized through the plurality of voltage stabilizing tubes. For example, as shown in fig. 3, the output circuit Vo1 is provided at the input terminal of the regulator tube Z1, so that a stable voltage output is realized by three series-connected regulator tubes Z1, Z2 and Z3; the output circuit Vo2 is arranged at the input end of the voltage-regulator tube Z2, so that a stable voltage output is realized by utilizing two voltage-regulator tubes Z2 and Z3 which are connected in series; the output circuit Vo3 is provided at the input terminal of the regulator tube Z3, thereby realizing a stable voltage output using the regulator tube Z3. An input filter capacitor C1 is provided in parallel with the plurality of constant voltage output circuits. Each constant voltage output circuit is respectively provided with an output filter capacitor in parallel; for example, as shown in fig. 3, the output circuit Vo1 is provided with an output filter capacitor C2 in parallel, the output circuit Vo2 is provided with an output filter capacitor C3 in parallel, and the output circuit Vo3 is provided with an output filter capacitor C4 in parallel.

The working principle of the circuit is that when the voltage-regulator tube works in a breakdown region, the current flowing through the voltage-regulator tube changes in a larger range, but the voltage change at the two ends of the voltage-regulator tube is very small, so that stable voltage is output; and a plurality of groups of different stable voltages are obtained by utilizing the series connection of a plurality of voltage-stabilizing tubes. A set of multiplexed output voltages can be easily obtained by using the circuit.

The voltage regulator tube voltage regulator circuit shown in fig. 3 has a simple structure, good voltage regulation performance and low cost, but the circuit can only be used in the occasions with small output current and small output current variation range.

In order to improve the above-mentioned disadvantages, the present invention improves the multi-output constant voltage circuit shown with reference to fig. 3, resulting in the multi-output constant voltage circuit shown with reference to fig. 4.

Referring to fig. 4, on the basis of the multi-output constant voltage circuit described above with reference to fig. 3, a tuning tube is provided for each output circuit. The adjusting tube is a triode; the base electrode of the triode is connected with the input end of the voltage stabilizing tube, the collector electrode of the triode is connected with the input end Vin of the whole multi-output constant voltage circuit, and the emitter electrode of the triode is connected with the output ends of the constant voltage output circuits. As shown in fig. 4, the output circuit Vo1 is provided with a tuning tube TR1, the output circuit Vo2 is provided with a tuning tube TR2, and the output circuit Vo3 is provided with a tuning tube TR 3.

The working principle of the circuit is that the equivalent resistance between the collector and the emitter of the triode is adjusted by utilizing the change of the output voltage, so that the output voltage stabilization is realized. The specific voltage stabilizing process is that when the output voltage is increased due to certain disturbance of the circuit, the voltage of the base electrode of the triode is stabilized by the voltage stabilizing tube, and the voltage of the base electrode is basically unchanged, so that the voltage between the base electrode and the emitting electrode of the triode is reduced, the equivalent resistance between the collector electrode and the emitting electrode of the triode is increased, and the output voltage is reduced. When the output voltage is decreased due to a certain disturbance of the circuit, the adjustment process is reversed, which is not described herein.

The circuit adopts an emitter output mode, the output resistor is very small, the load carrying capacity is strong, meanwhile, the triode has a current amplification effect, and the current injected into the base electrode is very small, so that the problem that a voltage stabilizing tube voltage stabilizing circuit cannot output large current is just avoided.

However, the voltage stabilization factor of the multi-output constant voltage circuit shown with reference to fig. 4 is not significantly improved as compared with the multi-output constant voltage circuit shown with reference to fig. 3. In addition, if the voltage stabilizing value of the selected voltage stabilizing tube has a positive temperature coefficient, the temperature rises, the voltage stabilizing value of the voltage stabilizing tube rises, the temperature falls and the voltage stabilizing value of the voltage stabilizing tube falls. The voltage stabilizing value of the voltage stabilizing tube is greatly influenced by the temperature, so that the phenomenon that the output voltage changes along with the change of the temperature is caused, and the phenomenon is called as temperature drift in the industry. In order to improve the temperature stability of the constant voltage circuit, the present invention improves the multi-output constant voltage circuit shown with reference to fig. 4, resulting in the multi-output constant voltage circuit shown with reference to fig. 5.

Referring to fig. 5, on the basis of the multi-output constant voltage circuit described with reference to fig. 4, a temperature compensation device is used for compensation, and a specific implementation method may be to connect a diode in series in the regulator tube loop, and use the positive voltage drop of the diode and the negative temperature coefficient for compensation. Specifically, as shown in fig. 5, in a loop in which a current-limiting resistor R1, a voltage regulator tube Z1, a diode D1 is serially connected in series after the voltage regulator tube Z3, from the input terminal Vin of the entire multi-output constant-voltage circuit, Z2, and Z3 are serially connected in series.

Referring to fig. 6, in order to improve the voltage stabilizing coefficient of the multi-output constant voltage circuit, a first-stage amplifying circuit may be added between the regulator tube and the voltage-stabilizing tube of the multi-output constant voltage circuit. Specifically, referring to fig. 6, the multi-output constant voltage circuit includes a plurality of constant voltage output circuits (two output circuits Vo1, Vo2 are shown in fig. 6). In the multi-output constant voltage circuit, a plurality of voltage-regulator tubes (two voltage-regulator tubes Z1, Z2 connected in series are shown in fig. 6) are connected in series, and a current-limiting resistor R1 is connected in series with the plurality of voltage-regulator tubes and is arranged on the side close to the input end Vin of the whole multi-output constant voltage circuit.

An input filter capacitor C1 is provided in parallel with the plurality of constant voltage output circuits. Each constant voltage output circuit is respectively provided with an output filter capacitor in parallel; for example, as shown in fig. 6, the output circuit Vo1 is provided with an output filter capacitor C2 in parallel, and the output circuit Vo2 is provided with an output filter capacitor C3 in parallel.

For each output circuit, the collector of the regulating tube is connected with the input end Vin of the whole multi-output constant voltage circuit, the emitter is connected with the output end of the constant voltage output circuit, and the base is respectively connected with the collector of the amplifying tube and the resistor (used as the collector resistor of the amplifying tube).

The collector of the amplifying tube is connected with the base of the adjusting tube and the resistor (used as the collector resistor of the amplifying tube), the emitter is connected with the input end of the voltage stabilizing tube, and the base is connected with the connecting wire of the two output sampling resistors.

One end of the resistor (used as collector resistance of the amplifier tube) is connected with the input end Vin of the whole multi-output constant voltage circuit, and the other end is connected with the collector of the amplifier tube and used as collector resistance of the amplifier tube.

The two output sampling resistors are connected in series, and a series circuit formed by the two output sampling resistors is connected in parallel with the output circuits (also in parallel with the output filter capacitors of each output circuit).

Specifically, for example, as shown in fig. 6, for the output circuit Vo 1:

the collector of the adjusting tube TR1 is connected to the input Vin of the whole multi-output constant voltage circuit, the emitter is connected to the output of the constant voltage output circuit Vo1, and the base is connected to the collector of the amplifying tube TR3 and the resistor R2 (used as the collector resistor of the amplifying tube TR 3), respectively.

The collector of the amplifying tube TR3 is respectively connected with the base of the adjusting tube TR1 and the resistor R2, the emitter is connected with the input end of the voltage regulator tube Z1, and the base is connected with the connecting wires of the output sampling resistors R4 and R5.

One end of the resistor R2 is connected to the input terminal Vin of the entire multi-output constant voltage circuit, and the other end is connected to the collector of the amplifier TR3, and serves as a collector resistance of the amplifier TR 3.

The output sampling resistors R4 and R5 are connected in series, and a series circuit formed by the output sampling resistors R4 and R5 is connected in parallel to the output circuit Vo1 (similarly connected in parallel to the output filter capacitor C2).

Similarly, for the output circuit Vo 2:

the collector of the adjusting tube TR2 is connected to the input Vin of the whole multi-output constant voltage circuit, the emitter is connected to the output of the constant voltage output circuit Vo2, and the base is connected to the collector of the amplifying tube TR4 and the resistor R3 (used as the collector resistor of the amplifying tube TR 4), respectively.

The collector of the amplifying tube TR4 is respectively connected with the base of the adjusting tube TR2 and the resistor R3, the emitter is connected with the input end of the voltage regulator tube Z2, and the base is connected with the connecting wires of the output sampling resistors R6 and R7.

One end of the resistor R3 is connected to the input terminal Vin of the entire multi-output constant voltage circuit, and the other end is connected to the collector of the amplifier TR4, and serves as a collector resistance of the amplifier TR 4.

The output sampling resistors R6 and R7 are connected in series, and a series circuit formed by the output sampling resistors R6 and R7 is connected in parallel to the output circuit Vo2 (similarly connected in parallel to the output filter capacitor C3).

The specific voltage stabilization process of the multi-output constant voltage circuit shown with reference to fig. 6 is: for example, for the output circuit Vo1, when the output voltage rises due to a certain disturbance of the circuit, the base voltage of the transistor of the amplifying tube TR3 obtained by the output sampling resistors R4 and R5 increases, so that the base and emitter voltages of the amplifying tube TR3 increase, the collector current flowing through the amplifying tube TR3 increases, the voltage drop across the collector resistor R2 of the amplifying tube TR3 increases, the base voltage of the adjusting tube TR1 decreases, so that the base and emitter voltages of the adjusting tube TR1 decrease, and the equivalent resistance between the collector and emitter of the transistor of the adjusting tube TR1 increases, so that the output voltage decreases. When the output voltage is decreased due to a certain disturbance of the circuit, the adjustment process is reversed, which is not described herein. For other output circuits (e.g., the output circuit Vo2), the adjustment process is the same as the output circuit Vo1, and is not described herein again.

The multi-output constant voltage circuit shown in fig. 6 adopts an emitter output mode, has a small output resistance and strong load carrying capacity, and adds an amplification link, so that the voltage stabilizing coefficient of the circuit is obviously improved. Meanwhile, as shown in fig. 5, a diode may be connected in series in the regulator tube loop, and the temperature stability of the output voltage may be improved by compensating for a negative temperature coefficient of a forward voltage drop of the diode (not shown).

In a specific preferred embodiment, in order to eliminate the influence of ripple current flowing through the current limiting resistor R1 on the regulated voltage of the voltage regulator tube, a constant current source circuit can be used to supply current to the voltage regulator tube instead of the current limiting resistor R1.

Referring to fig. 7, a specific constant current source circuit structure employed on the basis of the multi-output constant voltage circuit shown with reference to fig. 6 is as follows: the constant current source circuit is provided with a triode TR5, the emitting electrode of the triode TR5 is connected with the output end of a current-limiting resistor R1, the collecting electrode is connected with the input end of a voltage-stabilizing tube Z1 (namely a voltage-stabilizing tube Z1) close to the input end Vin of the whole multi-output constant voltage circuit, and the base electrode is connected with a connecting line of the voltage-stabilizing tube (namely a voltage-stabilizing tube Z3) of the constant current source circuit and the resistor (namely a resistor R8) of the constant current source circuit; the regulator tube Z3 and the resistor R8 are connected in series to form a series circuit, and the series circuit is connected in parallel with a plurality of constant voltage output circuits (or in parallel with the input filter capacitor C1).

The constant current source circuit described above is applicable to any of the multi-output constant voltage circuits described above with reference to fig. 3 to 6.

A regulated power supply using the above-described multi-output constant voltage circuits (for example, the multi-output constant voltage circuits described above with reference to fig. 3 to 7) respectively also falls within the scope of the present invention.

The multi-output constant voltage circuit and the voltage-stabilized power supply adopting the same can conveniently and quickly obtain any output voltage value, and are low in cost. Meanwhile, the reliability of the circuit is high due to the fact that the number of used components is small. The multi-output constant voltage circuit provided by the invention has the advantages of simple structure, low implementation difficulty and high reliability, and greatly reduces the cost while meeting various requirements.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.