High-efficiency linear power supply

Abstract

The utility model discloses a high-efficiency linear power supply, which relates to the field of power supplies, and comprises a voltage transformation, rectification and filtering module, a voltage difference feedback module, a voltage conversion and rectification module and an output module, the voltage difference feedback module is used for adjusting the signal intensity fed back to the input voltage adjusting module based on the magnitude of the voltage on the adjusting tube; the input voltage adjusting module is used for changing the magnitude of the input alternating current output to the transformation rectification filtering module based on the magnitude of the input signal intensity; the beneficial effects of the utility model are that the working frequency is power frequency, and high-frequency noise is not generated; the feedback quantity is the pressure difference of the adjusting pipe, so that the pressure difference of the adjusting pipe can be stabilized at 1.5 V, and the loss of the adjusting pipe is effectively reduced; full-bridge topology is adopted, inductor follow current is used on the receiving side, and the capacity of an output capacitor can be effectively reduced; a special PWM management chip is not needed, the control circuit is simple, and the cost is low.

Description

Technical Field

[0001] This utility model relates to the field of power supplies, specifically a high-efficiency linear power supply. Background Technology

[0002] Traditional linear power supplies typically consist of a power frequency transformer, a rectifier and filter circuit, and a linear regulating transistor (such as a transistor or MOSFET). The regulating transistor operates in the amplification region, and the output voltage is regulated by changing the transistor's voltage drop. However, when the input and output voltage difference is large, the regulating transistor consumes a lot of power (P = (Vin - Vout)Iout), resulting in low efficiency (usually below 50%) and severe heat generation. This necessitates the use of multiple regulating transistors in parallel and the use of large heat sinks.

[0003] Existing improvement solutions typically employ high-frequency switching pre-regulation technology, such as adding a switching buck circuit before the regulating transistor to reduce the input-output voltage difference. However, the following problems still exist:

[0004] 1. Switching circuits operating at frequencies between 50-400kHz will generate high-frequency noise interference and output high-frequency ripple noise;

[0005] 2. A complete high-frequency switching regulator circuit is required, including a PWM drive circuit, inductor, switching transistor and freewheeling diode, which is costly.

[0006] Therefore, the existing improved linear power supply has problems such as noise interference and high cost, and needs to be improved. Utility Model Content

[0007] The purpose of this invention is to provide a high-efficiency linear power supply to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, this utility model provides the following technical solution:

[0009] A high-efficiency linear power supply, comprising:

[0010] The transformer rectifier filter module is used to convert the input AC power into stable DC power and output it to the differential pressure feedback module.

[0011] The differential pressure feedback module is used to adjust the signal strength fed back to the input voltage adjustment module based on the voltage on the regulating tube.

[0012] The input voltage adjustment module is used to change the magnitude of the input AC current output to the transformer rectifier filter module based on the magnitude of the input signal strength.

[0013] The transformer rectifier filter module is connected to the differential pressure feedback module, and the differential pressure feedback module is connected to the input voltage adjustment module.

[0014] As a further embodiment of this utility model: the transformer rectifier filter module includes a transformer T1, a rectifier DB1, a capacitor C1, and an inductor L1. The first end of the transformer T1 is connected to the live wire L, the second end of the transformer T1 is connected to the input voltage adjustment module, the third and fourth ends of the transformer T1 are respectively connected to the second and third ends of the rectifier DB1, the fourth end of the rectifier DB1 is grounded, the first end of the rectifier DB1 is connected to one end of the inductor L1, the other end of the inductor L1 is connected to one end of the capacitor C1 and the differential voltage feedback module, and the other end of the capacitor C1 is grounded.

[0015] As a further embodiment of this utility model: the differential pressure feedback module includes an adjustment transistor Q2, a diode D3, a resistor R3, a transistor Q3, a resistor R2, a resistor R4, an optocoupler U1, and an optocoupler U2. The first end of the adjustment transistor Q2 is connected to the transformer rectifier filter module, the positive terminal of the diode D3, one end of the resistor R2, and one end of the resistor R4. The second end of the adjustment transistor Q2 is connected to the voltage and current dual closed-loop feedback circuit. The third end of the adjustment transistor Q2 is connected to one end of the capacitor C2 and the emitter of the transistor Q3. The other end of the capacitor C2 is grounded. The base of the transistor Q3 is connected to one end of the resistor R3. The other end of the resistor R3 is connected to the negative terminal of the diode D3. The collector of the transistor Q3 is connected to one end of the emitter side of the optocoupler U1 (specifically U1A) and one end of the emitter side of the optocoupler U2 (specifically U2A). The other end of the emitter side of the optocoupler U1 is connected to the other end of the resistor R2. The other end of the emitter side of the optocoupler U2 is connected to the other end of the resistor R4.

[0016] As a further improvement of this invention, the regulating transistor Q2 is a MOS transistor.

[0017] As a further embodiment of this utility model: the input voltage adjustment module includes an optocoupler U1, an optocoupler U2, a diode D1, a diode D2, a capacitor C3, a TVS protection transistor ZD1, a resistor R1, and a bidirectional thyristor Q1. One receiving end of the optocoupler U1 (specifically U1B) is connected to the positive terminal of the diode D1. The other receiving end of the optocoupler U1 is connected to one end of the capacitor C3, one end of the TVS protection transistor ZD1, one end of the resistor R1, one receiving end of the optocoupler U2 (specifically U2B), the other receiving end of the optocoupler U2 is connected to the negative terminal of the diode D2, the positive terminal of the diode D2 is connected to the negative terminal of the diode D1, the other end of the capacitor C3, the neutral line N, the first terminal of the bidirectional thyristor Q1, the other end of the TVS protection transistor ZD1 is connected to the second terminal of the bidirectional thyristor Q1, the third terminal of the bidirectional thyristor Q1 is connected to the other end of the resistor R1, and a transformer rectification and filtering module.

[0018] Compared with the prior art, the beneficial effects of this utility model are: the working frequency of this utility model is the power frequency and will not generate high-frequency noise; the feedback quantity is the voltage difference of the regulating tube, which can stabilize the voltage difference of the regulating tube at 1.5V and effectively reduce the loss of the regulating tube; the full bridge topology uses inductor freewheeling on the receiving side, which can effectively reduce the capacity of the output capacitor; no dedicated PWM management chip is required, the control circuit is simple and the cost is low. Attached Figure Description

[0019] Figure 1 This is a circuit diagram of a high-efficiency linear power supply. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0021] Please see Figure 1 A high-efficiency linear power supply, comprising:

[0022] The transformer rectifier filter module is used to convert the input AC power into stable DC power and output it to the differential pressure feedback module.

[0023] The differential pressure feedback module is used to adjust the signal strength fed back to the input voltage adjustment module based on the voltage on the regulating tube.

[0024] The input voltage adjustment module is used to change the magnitude of the input AC current output to the transformer rectifier filter module based on the magnitude of the input signal strength.

[0025] The transformer rectifier filter module is connected to the differential pressure feedback module, and the differential pressure feedback module is connected to the input voltage adjustment module.

[0026] In this embodiment: Please refer to Figure 1 The transformer-rectifier-filter module includes a transformer T1, a rectifier DB1, a capacitor C1, and an inductor L1. The first end of the transformer T1 is connected to the live wire L, the second end of the transformer T1 is connected to the input voltage adjustment module, the third and fourth ends of the transformer T1 are connected to the second and third ends of the rectifier DB1, respectively, the fourth end of the rectifier DB1 is grounded, the first end of the rectifier DB1 is connected to one end of the inductor L1, the other end of the inductor L1 is connected to one end of the capacitor C1 and the differential voltage feedback module, and the other end of the capacitor C1 is grounded.

[0027] The input AC power is stepped down by transformer T1, converted to DC by rectifier DB1, and filtered by inductor L1 and capacitor C1, finally becoming stable DC power.

[0028] In this embodiment: Please refer to Figure 1 The differential pressure feedback module includes an adjustment transistor Q2, a diode D3, a resistor R3, a transistor Q3, a resistor R2, a resistor R4, an optocoupler U1, and an optocoupler U2. The first end of the adjustment transistor Q2 is connected to the transformer rectifier filter module, the positive terminal of the diode D3, one end of the resistor R2, and one end of the resistor R4. The second end of the adjustment transistor Q2 is connected to the voltage and current dual closed-loop feedback circuit. The third end of the adjustment transistor Q2 is connected to one end of the capacitor C2 and the emitter of the transistor Q3. The other end of the capacitor C2 is grounded. The base of the transistor Q3 is connected to one end of the resistor R3. The other end of the resistor R3 is connected to the negative terminal of the diode D3. The collector of the transistor Q3 is connected to one end of the emitter side of the optocoupler U1 (specifically U1A) and one end of the emitter side of the optocoupler U2 (specifically U2A). The other end of the emitter side of the optocoupler U1 is connected to the other end of the resistor R2. The other end of the emitter side of the optocoupler U2 is connected to the other end of the resistor R4.

[0029] In this embodiment: Please refer to Figure 1 The regulating transistor Q2 is a MOSFET.

[0030] The DC current passes through the regulating transistor Q2 and the transistor Q3 to output voltage. Then, it passes through the sampling resistor RS1 (the output voltage and current information are obtained through the sampling resistor, and then the conduction frequency of the regulating transistor Q2 is controlled through the feedback circuit. This is a common technique and will not be described in detail here) to output voltage VOUT.

[0031] In this embodiment: Please refer to Figure 1 The input voltage adjustment module includes optocoupler U1, optocoupler U2, diode D1, diode D2, capacitor C3, TVS protection diode ZD1, resistor R1, and triac Q1. One receiving end of optocoupler U1 (specifically U1B) is connected to the positive terminal of diode D1. The other receiving end of optocoupler U1 is connected to one end of capacitor C3, one end of TVS protection diode ZD1, one end of resistor R1, one receiving end of optocoupler U2 (specifically U2B), the other receiving end of optocoupler U2 is connected to the negative terminal of diode D2, the positive terminal of diode D2 is connected to the negative terminal of diode D1, the other end of capacitor C3, neutral line N, the first terminal of triac Q1, the other end of TVS protection diode ZD1 is connected to the second terminal of triac Q1, the third terminal of triac Q1 is connected to the other end of resistor R1, and a transformer, rectifier, and filter module.

[0032] The AC power is converted into an intermediate voltage Vmid that is close to the target output voltage Vout. Vmid is dynamically adjusted according to the output demand to stabilize the voltage difference of the regulating tube Q2 at 1.5V.

[0033] Working principle: When the Vmid voltage increases, and the voltage difference of the regulating transistor Q2 is greater than the voltage of diode D3 + voltage of resistor R3 + Vbe voltage of transistor Q3 (the voltage difference between the base and emitter of transistor Q3) (approximately 1.5V), the emitter current of optocouplers U1 and U2 increases, the receiver current also increases, the charging current of capacitor C3 decreases, the charging time increases, the conduction time of bidirectional thyristor Q1 is delayed, the conduction pulse width narrows, the input AC current of transformer T1 decreases, and thus the Vmid voltage decreases, forming negative feedback, which stabilizes the voltage difference of the regulating transistor Q2 at 1.5V.

[0034] Linear adjustment circuit: The voltage and current dual closed-loop feedback circuit composed of error amplifier and adjustment tube Q2 precisely fine-tunes the target output voltage VOUT, while suppressing the power frequency ripple generated by the power frequency dynamic pre-stabilization module.

[0035] Composite feedback mechanism:

[0036] Main feedback loop: The error amplifier forms a voltage and current dual closed-loop feedback circuit to control the conduction status of the regulating transistor Q2;

[0037] Auxiliary feedback loop: Adjust the pre-stabilized voltage target value according to the voltage difference (Vmid-Vout) of regulating tube Q2 to ensure that the voltage difference is always in the low power consumption range.

[0038] Experimental data comparison table (based on input AC mains, output adjustable from 0-30V, maximum current 5A):

[0039]

[0040] The working principle of this utility model is as follows: the transformer rectifier filter module is used to convert the input AC power into stable DC power and output it to the differential voltage feedback module; the differential voltage feedback module is used to adjust the signal strength fed back to the input voltage adjustment module based on the voltage on the regulating tube; the input voltage adjustment module is used to change the magnitude of the input AC power output to the transformer rectifier filter module based on the magnitude of the input signal strength.

[0041] This invention adds an input voltage adjustment module, inductor L1, diode D3, resistor R3, transistor Q3, resistor R2, resistor R4, optocoupler U1, and optocoupler U2 to the traditional linear power supply. The circuit structure is simple, does not generate high-frequency noise, and is low in cost.

[0042] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects.

[0043] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A high efficiency linear power supply characterized by, This high-efficiency linear power supply includes: The transformer rectifier filter module is used to convert the input AC power into stable DC power and output it to the differential voltage feedback module. The differential pressure feedback module is used to adjust the signal strength fed back to the input voltage adjustment module based on the voltage on the regulating tube. The input voltage adjustment module is used to change the magnitude of the input AC current output to the transformer rectifier filter module based on the magnitude of the input signal strength. The transformer rectifier filter module is connected to the differential pressure feedback module, and the differential pressure feedback module is connected to the input voltage adjustment module.

2. The high efficiency linear power supply of claim 1, wherein, The transformer-rectifier-filter module includes a transformer T1, a rectifier DB1, a capacitor C1, and an inductor L1. The first terminal of the transformer T1 is connected to the live wire L, the second terminal of the transformer T1 is connected to the input voltage adjustment module, the third and fourth terminals of the transformer T1 are connected to the second and third terminals of the rectifier DB1, respectively, and the fourth terminal of the rectifier DB1 is grounded. The first terminal of the rectifier DB1 is connected to one end of the inductor L1, the other end of the inductor L1 is connected to one end of the capacitor C1 and the differential voltage feedback module, and the other end of the capacitor C1 is grounded.

3. The high efficiency linear power supply of claim 1, wherein, The differential pressure feedback module includes an adjustment transistor Q2, a diode D3, a resistor R3, a transistor Q3, a resistor R2, a resistor R4, an optocoupler U1, and an optocoupler U2. The first end of the adjustment transistor Q2 is connected to the transformer rectifier filter module, the positive terminal of the diode D3, one end of the resistor R2, and one end of the resistor R4. The second end of the adjustment transistor Q2 is connected to the voltage and current dual closed-loop feedback circuit. The third end of the adjustment transistor Q2 is connected to one end of the capacitor C2 and the emitter of the transistor Q3. The other end of the capacitor C2 is grounded. The base of the transistor Q3 is connected to one end of the resistor R3. The other end of the resistor R3 is connected to the negative terminal of the diode D3. The collector of the transistor Q3 is connected to one end of the emitter side of the optocoupler U1 and one end of the emitter side of the optocoupler U2. The other end of the emitter side of the optocoupler U1 is connected to the other end of the resistor R2. The other end of the emitter side of the optocoupler U2 is connected to the other end of the resistor R4.

4. The high efficiency linear power supply of claim 3, wherein, The regulating transistor Q2 is a MOSFET.

5. The high efficiency linear power supply of any one of claims 1, 3, 4, wherein, The input voltage adjustment module includes optocoupler U1, optocoupler U2, diode D1, The following components are connected to the system: diode D2, capacitor C3, TVS protection diode ZD1, resistor R1, and triac Q1. One end of the receiving side of optocoupler U1 is connected to the positive terminal of diode D1. The other end of the receiving side of optocoupler U1 is connected to one end of capacitor C3, one end of TVS protection diode ZD1, one end of resistor R1, one end of the receiving side of optocoupler U2, the other end of the receiving side of optocoupler U2 is connected to the negative terminal of diode D2, the positive terminal of diode D2 is connected to the negative terminal of diode D1, the other end of capacitor C3, neutral line N, the first terminal of triac Q1, the other end of TVS protection diode ZD1 is connected to the second terminal of triac Q1, the third terminal of triac Q1 is connected to the other end of resistor R1, and a transformer rectifier filter module.

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