Adjustable voltage-stabilizing and current-stabilizing linear power supply

Abstract

An adjustable voltage-stabilizing and current-stabilizing linear power supply comprises a transformer, a voltage gear adjusting circuit, an output voltage gear judging circuit, a rectifying and filtering circuit 1, a voltage stabilizing circuit, an output voltage adjusting circuit, an output voltage feedback circuit, an output voltage detecting circuit and a voltage setting circuit. The device comprises a voltage-stabilizing and current-stabilizing switching circuit, a current-stabilizing circuit, an output current adjusting circuit, an output current feedback circuit, a voltage-stabilizing and current-stabilizing mode setting circuit, a current setting circuit, an output current detection circuit, a positive voltage stabilizer, a negative voltage stabilizer, a positive power supply, a negative power supply, a microprocessor, a key circuit, a display circuit and an output. The front end is provided with display and operation components, and the rear end is provided with AC power supply input and DC power supply output components. The device has two working modes, namely a voltage stabilization mode and a current stabilization mode. In a voltage stabilization mode, the voltage stabilization and current stabilization switching circuit skips over the current stabilization circuit, and the output current feedback circuit directly outputs. And in the steady-current working mode, the voltage stabilizing circuit is connected in series with the steady-current circuit and the output current feedback circuit.

Description

Technical Field

[0001] The utility model relates to a linear power supply, in particular to an adjustable voltage-stabilized and current-stabilized linear power supply. Background Art

[0002] With the continuous development of science and technology, the production of electronic products in scientific research, laboratories, factories and daily life has higher and higher technological levels, and the requirements for the functions and performance indicators of linear power supplies are becoming more and more stringent. The existing linear power supplies are generally composed of transformers, rectifiers, three-terminal voltage regulators and filter circuits. Generally, the voltage-stabilized and current-stabilized linear power supplies have large ripples, high noise, low voltage adjustment cannot reach 0V, and the accuracy is not high enough. Summary of the invention

[0003] The purpose of the utility model is to provide an adjustable voltage-stabilized and current-stabilized linear power supply to solve the problems of the existing voltage-stabilized and current-stabilized linear power supplies. To achieve the above purpose, the technical solution adopted by the utility model is as follows:

[0004] An adjustable voltage-stabilized and current-stabilized linear power supply is characterized in that it includes a transformer, a voltage gear adjustment circuit, an output voltage gear discrimination circuit, a rectifier and filter circuit 1, a voltage stabilizing circuit, an output voltage regulating circuit, an output voltage feedback circuit, an output voltage detection circuit, a voltage setting circuit, a voltage-stabilizing and current-stabilizing switching circuit, a current stabilizing circuit, an output current regulating circuit, an output current feedback circuit, a voltage-stabilizing and current-stabilizing mode setting, a current setting circuit, an output current detection circuit, positive voltage stabilization, negative voltage stabilization, a positive power supply, a negative power supply, a microprocessor, a key circuit, a display circuit, and an output.

[0005] The utility model discloses an adjustable voltage-stabilized and current-stabilized linear power supply, which is in the shape of a rectangular parallelepiped, with a display circuit and a key circuit located at the front end, and an AC power input and output located at the rear end.

[0006] An adjustable voltage-stabilized and current-stabilized linear power supply is characterized in that it has two working modes, voltage-stabilized mode and current-stabilized mode. In voltage-stabilized mode, a voltage-stabilized and current-stabilized switching circuit skips a current-stabilized circuit and an output current feedback circuit, and directly connects the output and output current detection circuits. In current-stabilized mode, the voltage-stabilized circuit is connected in series with the current-stabilized circuit and the output current feedback circuit.

[0007] Furthermore, the voltage gear adjustment circuit is connected to the transformer, the output voltage discrimination circuit, and the rectifier filter circuit 1. When the output voltage is higher than a certain value, it automatically switches to the winding with a higher output voltage of the transformer. The rectifier filter 2 is connected to the positive voltage regulator and the negative voltage regulator to output a positive power supply and a negative power supply with the same voltage amplitude and opposite directions. The rectifier filter 3 is connected to the control voltage regulator to output the power supply of the control circuit.

[0008] Furthermore, the voltage stabilizing circuit is a circuit mainly composed of a three-terminal voltage stabilizing chip, which is connected to the rectifier filter circuit 1, the output voltage gear discrimination circuit, the output voltage feedback circuit, and the output. The output voltage feedback circuit is connected to the voltage stabilizing circuit, the output voltage regulating circuit, and the output. The output voltage regulating circuit is also connected to the setting voltage circuit and the negative power supply.

[0009] Furthermore, the voltage and current stabilization switching circuit is connected to the output, current stabilization circuit, voltage and current stabilization mode setting, output feedback circuit and output current detection. The voltage and current stabilization switching circuit uses a relay with two normally open and normally closed contacts. The best working mode is to connect the normally open contact in the voltage stabilization mode and the normally closed contact in the current stabilization mode. Because the linear power supply generates relatively large heat in the current stabilization mode.

[0010] Furthermore, in the voltage regulation mode, the output current detection circuit is only used to display the real-time current and is not used as a control quantity. The negative power supply, the output voltage setting circuit, and the output voltage adjustment circuit are used to provide the set voltage to the output voltage feedback circuit. The higher the set voltage, the higher the output voltage.

[0011] Furthermore, the output voltage feedback circuit is a negative feedback circuit formed by an operational amplifier. When the output setting voltage is constant, the load resistance decreases, the voltage across the load decreases, and the input voltage difference of the output voltage feedback circuit increases, so that the output voltage increases and the voltage across the load remains unchanged. The output voltage feedback circuit has a fast response speed and a small ripple voltage.

[0012] Furthermore, in the steady current mode, the voltage stabilizing circuit is connected in series with the steady current circuit. At this time, the output of the voltage setting circuit is set to the maximum value, so that in the steady current working mode, within the voltage output range, the current is not limited by the voltage, and the current maintains the set value when the load fluctuates.

[0013] Furthermore, the current setting circuit is connected to the output current regulating circuit. The higher the output voltage of the current setting circuit is, the higher the output voltage of the output current regulating circuit is, and the greater the current output by the current stabilizing circuit is.

[0014] Furthermore, the output current feedback circuit is a negative feedback circuit composed of an operational amplifier. When the output voltage of the current circuit is set constant, the output current does not change with the fluctuation of the load, and the constant current is maintained. The response speed is fast, so that the ripple current is small.

[0015] The output voltage detection circuit and the output current detection circuit are connected to a microprocessor and are used for voltage and current display and control.

[0016] The output voltage regulating circuit is connected with the output voltage feedback circuit, the negative power supply and the voltage setting circuit, so that the output voltage of the voltage stabilizing circuit reaches 0V.

[0017] The positive power supply, negative power supply and control power supply are independent of each other, so that the output noise is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of adjustable voltage and current stabilizing linear power supply

[0019] Figure 2 Schematic diagram of internal power supply connections. Implementation

[0020] The present invention is further described below in conjunction with the accompanying drawings and embodiments. The embodiments of the present invention include but are not limited to the following embodiments.

[0021] See also Figure 1 , an adjustable voltage-stabilized and current-stabilized linear power supply, including a transformer, a voltage gear adjustment circuit, an output voltage gear discrimination circuit, a rectifier and filter circuit 1, a voltage stabilization circuit, an output voltage regulation circuit, an output voltage feedback circuit, an output voltage detection circuit, a voltage setting circuit, a rectifier and filter 2, positive voltage stabilization, negative voltage stabilization, a rectifier and filter 3, a control voltage stabilization, a voltage and current stabilization switching circuit, a current stabilization circuit, an output current regulation circuit, an output current feedback circuit, a voltage and current stabilization mode setting, a current setting circuit, an output current detection circuit, a microprocessor, a key circuit, and a display circuit.

[0022] The utility model discloses an adjustable voltage-stabilized and current-stabilized linear power supply, which has two working modes, a voltage-stabilized mode and a current-stabilized mode, and is switched by a voltage-stabilized and current-stabilized switching circuit according to the working mode set by the user.

[0023] In voltage regulation mode, the circuit skips the current regulation circuit and output current feedback circuit, and directly connects the output to the output current detection circuit. The output current detection circuit is only used to display the real-time current and is not used as a control quantity.

[0024] The negative power supply, output voltage setting circuit, and output voltage regulating circuit are used to provide the setting voltage to the output voltage feedback circuit. The higher the setting voltage, the higher the output voltage. The output voltage feedback circuit is a negative feedback circuit of the operational amplifier. When the output voltage is set to a certain value, if the load resistance is reduced, the voltage across the load drops, and the input voltage difference of the output voltage feedback circuit increases, so that the output voltage increases and the voltage across the load remains unchanged. The output voltage feedback circuit has a fast response speed, which makes the ripple voltage very small.

[0025] In the steady current mode, the voltage regulator circuit is connected in series with the steady current circuit. At this time, the voltage circuit is set to the maximum value, so that in the steady current working mode, within the voltage output range, the current is not limited by the voltage. The higher the output voltage of the current circuit is set, the greater the current output by the steady current circuit is made by the output current regulation circuit. The output current feedback circuit is also a negative feedback circuit composed of an operational amplifier. When the output voltage of the current circuit is set to a certain value, the output current does not change with the fluctuation of the load, and the constant current is maintained unchanged.

[0026] The utility model is provided with a microprocessor for human-computer interaction, parameter setting, data collection and data processing, output control stability, and sending display real-time data to a display circuit.

[0027] Two buttons and one knob are set: ON / OFF is used to turn the output on and off, and the CV / CC button is used to set the voltage or current steady working mode. One knob is used to add or subtract values ​​when setting data.

[0028] Set up 2 rows of 4-digit digital tubes, one row displays voltage and the other displays current. When setting, it displays the output voltage, output current value, voltage output range, current output range, internal parameters, etc. When working, it displays the real-time output current and voltage value of the output circuit.

Claims

1. An adjustable voltage-stabilized and current-stabilized linear power supply, characterized in that: It includes a transformer, a voltage gear adjustment circuit, an output voltage gear discrimination circuit, a rectifier filter circuit 1, a voltage stabilization circuit, an output voltage regulation circuit, an output voltage feedback circuit, an output voltage detection circuit, a voltage setting circuit, a voltage and current stabilization switching circuit, a current stabilization circuit, an output current regulation circuit, an output current feedback circuit, a voltage and current stabilization mode setting, a current setting circuit, an output current detection circuit, positive voltage stabilization, negative voltage stabilization, a positive power supply, a negative power supply, a microprocessor, a key circuit, a display circuit, and an output.

2. According to claim 1, an adjustable voltage-stabilized and current-stabilized linear power supply is characterized in that: The adjustable voltage-stabilized and current-stabilized linear power supply has two working modes, voltage-stabilized mode and current-stabilized mode. In voltage-stabilized mode, the voltage-stabilized and current-stabilized switching circuit skips the current-stabilized circuit and the output current feedback circuit, and the output is directly connected to the output current detection circuit. In current-stabilized working mode, the voltage-stabilized circuit is connected in series with the current-stabilized circuit, the output current feedback circuit, the output current detection circuit, and the output.

3. The adjustable voltage- and current-stabilized linear power supply according to claim 1, characterized in that: The transformer is connected with the voltage gear adjustment circuit, the rectifier filter 2 and the rectifier filter 3.

4. The adjustable voltage- and current-stabilized linear power supply according to claim 2, characterized in that: The voltage gear adjustment circuit is connected with the transformer, the output voltage discrimination circuit, and the rectifier filter circuit 1. When the output voltage is higher than a certain value, it automatically switches to the winding with a higher output voltage of the transformer. The rectifier filter 2 is connected with the positive voltage regulator and the negative voltage regulator to output the positive power supply and the negative power supply with the same voltage amplitude and opposite directions. The rectifier filter 3 is connected with the control voltage regulator to output the power supply of the control circuit.

5. The adjustable voltage- and current-stabilized linear power supply according to claim 1, characterized in that: The voltage stabilizing circuit is a circuit mainly composed of a three-terminal voltage stabilizing chip, which is connected to the rectifier filter circuit 1, the output voltage gear discrimination circuit, the output voltage feedback circuit, and the output. The output voltage feedback circuit is connected to the voltage stabilizing circuit, the output voltage regulating circuit, and the output. The output voltage regulating circuit is also connected to the setting voltage circuit and the negative power supply.

6. The adjustable voltage- and current-stabilized linear power supply according to claim 1, characterized in that: The voltage and current stabilization switching circuit is connected with the output, the current stabilization circuit, the voltage and current stabilization mode setting, the output feedback circuit and the output current detection.

7. The adjustable voltage- and current-stabilized linear power supply according to claim 1, characterized in that: The current stabilizing circuit is connected to the voltage stabilizing and current stabilizing switching circuit, the output current regulating circuit, and the output current feedback circuit; the output current regulating circuit is connected to the current setting circuit and the output current feedback circuit; the output current feedback circuit is connected to the voltage stabilizing and current stabilizing switching circuit, the output current detection circuit, and the output current regulating circuit.

8. The adjustable voltage- and current-stabilized linear power supply according to claim 1, characterized in that: The microprocessor is connected to a voltage setting circuit, a current setting circuit, an output voltage detection circuit, an output current detection circuit, a voltage and current stabilization mode setting, a key input, a display circuit, and a control power supply.

9. The adjustable voltage- and current-stabilized linear power supply according to claim 1, characterized in that: The positive power supply is connected to the voltage setting circuit, the current setting circuit, the output voltage feedback circuit, the output voltage regulation circuit, the output voltage detection circuit, the output current feedback circuit, and the output current detection circuit; the negative power supply is connected to the output voltage feedback circuit, the output voltage regulation circuit, the output voltage detection circuit, the output current feedback circuit, and the output current detection circuit.

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