Over-voltage and under-voltage protection circuit

Abstract

The utility model discloses an overvoltage and undervoltage protection circuit which comprises an undervoltage detection module, an overvoltage detection module and a protection output module. The under-voltage detection module is used for grounding the positive power supply end of a relay of the protection output module when detecting that the power supply is under-voltage, so that the relay cannot be closed, and power supply voltage output is prohibited; and the overvoltage detection module is used for grounding the negative power supply end of the relay of the protection output module when the overvoltage of the power supply is detected, so that the relay cannot be closed, and the output of the power supply voltage is prohibited. By arranging the undervoltage detection module and the overvoltage detection module, when the undervoltage or overvoltage of the power supply is detected, the voltage output of the power supply is prohibited, and the components of the circuit are effectively protected. The circuit structure is simple, the cost of the protection circuit of the product is reduced, and the production efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of medical equipment circuit protection, and particularly relates to an over-voltage and under-voltage protection circuit. Background Art

[0002] Medical equipment usually requires power supply with multiple voltage values for different parts with different rated voltages in the equipment. This requires the paired medical power supply to have multiple outputs, and during use, the requirement for power supply stability is also relatively high, and there should be no unstable power supply situation. To meet the above requirements, current medical power supplies are designed with corresponding protection circuits to perform corresponding emergency processing when the power supply is unstable. Most of the current medical power supplies on the market achieve the switching function through a standby chip, and usually, a separate protection unit is externally connected for each voltage output for corresponding protection.

[0003] A stable power supply voltage is crucial for the normal operation of medical equipment. Too high or too low input voltage may cause the electronic circuit to output incorrect signals, resulting in the system being unable to operate normally. Especially when the power grid fluctuates greatly, there are instantaneous interferences, or equipment failures, it may even cause irreversible damage to components. The surge suppression circuit needs to suppress over-voltage surges so that the output voltage is always maintained within the power supply range allowed by the equipment, and the under-voltage protection functional circuit can turn off the power supply in a timely manner when the input voltage is lower than the set value, thereby protecting the power supply equipment from damage to ensure the stability and safety of the power supply system.

[0004] However, the existing over-voltage and under-voltage protection circuits for medical equipment have disadvantages such as using more components, relatively complex circuits, being not conducive to processing production and cost control. Summary of the Invention

[0005] The existing over-voltage and under-voltage protection circuits for medical equipment use more components, the circuits are relatively complex, which not only affects the production efficiency but also raises the cost of the product.

[0006] In view of the above problems, an over-voltage and under-voltage protection circuit is proposed. By setting an under-voltage detection module and an over-voltage detection module, when the power supply is detected to be under-voltage or over-voltage, the power supply voltage output is prohibited, effectively protecting the components of the circuit. The circuit structure is simple, reducing the cost of the protection circuit of the product and improving the production efficiency.

[0007] An over-voltage and under-voltage protection circuit includes:

[0008] An under-voltage detection module;

[0009] An over-voltage detection module;

[0010] A protection output module;

[0011] The undervoltage detection module is electrically connected to the overvoltage detection module and the protection output module;

[0012] The overvoltage detection module is also electrically connected to the protection output module;

[0013] The undervoltage detection module is configured to ground the positive power supply terminal of the relay of the protection output module when detecting that the power supply is undervoltage, so that the relay cannot be attracted and the power supply voltage output is prohibited;

[0014] The overvoltage detection module is configured to ground the negative power supply terminal of the relay of the protection output module when detecting that the power supply is overvoltage, so that the relay cannot be attracted and the power supply voltage output is prohibited.

[0015] Combined with the over-undervoltage protection circuit of the present invention, in the first possible implementation manner, the undervoltage detection module includes:

[0016] A first optocoupler unit;

[0017] A first triode unit;

[0018] The first optocoupler unit is electrically connected to the first triode unit;

[0019] The first optocoupler unit is configured to output a high level to the first triode unit when detecting that the power supply voltage is undervoltage.

[0020] Combined with the first possible implementation manner of the present invention, in the second possible implementation manner, the overvoltage detection module includes:

[0021] A second optocoupler unit;

[0022] A second triode unit;

[0023] The second optocoupler unit is electrically connected to the second triode unit;

[0024] The second optocoupler unit is configured to output a low level to the second triode unit when detecting that the power supply voltage is overvoltage.

[0025] Combined with the second possible implementation manner of the present invention, in the third possible implementation manner, the first optocoupler unit includes:

[0026] A first optocoupler and a first resistor;

[0027] The first triode unit includes:

[0028] A second resistor, a third resistor, a first capacitor and a first triode;

[0029] The first pin of the first optocoupler is connected to the power supply, the second pin is electrically connected to the first end of the first resistor, and the third pin is electrically connected to the first end of the second resistor, the first end of the first capacitor, and the base of the first triode;

[0030] The second end of the first resistor is grounded and electrically connected to the overvoltage detection module;

[0031] The second end of the second resistor is electrically connected to the power supply, and the second end of the first capacitor and the emitter of the first triode are commonly connected and then grounded;

[0032] The collector of the first triode is electrically connected to the first end of the third resistor and the protection output module;

[0033] The second end of the third resistor is electrically connected to the power supply.

[0034] Combined with the third possible implementation manner of the present utility model, in the fourth possible implementation manner, the second optocoupler unit includes a first diode, a first zener diode, a fourth resistor, and a second optocoupler; the second triode unit includes:

[0035] The second triode unit includes a fifth resistor, a second capacitor, and a second triode;

[0036] The anode of the first diode is electrically connected to the first end of the first resistor and the second pin of the first optocoupler, the cathode is electrically connected to the first end of the fourth resistor, and the second end of the fourth resistor is electrically connected to the first pin of the second optocoupler;

[0037] The anode of the first zener diode is electrically connected to the second end of the first resistor, and the cathode is electrically connected to the second pin of the second optocoupler;

[0038] The third pin of the second optocoupler is electrically connected to the first end of the fifth resistor, the first end of the second capacitor, and the base of the second triode;

[0039] The second end of the fifth resistor is connected to the power supply, and the second end of the second capacitor and the emitter of the second triode are commonly connected and then grounded;

[0040] The collector of the second triode is electrically connected to the protection output module.

[0041] Combined with the fourth possible implementation manner of the present utility model, in the fifth possible implementation manner, the protection output module includes:

[0042] A second diode;

[0043] A relay;

[0044] The cathode of the second diode is electrically connected to the first end of the third resistor, the positive power supply terminal of the relay, and the collector of the first triode;

[0045] The anode of the second diode is electrically connected to the negative power supply terminal of the relay and the collector of the second triode.

[0046] Combined with the fifth possible implementation manner of the present utility model, in the sixth possible implementation manner, the conduction voltage value between the first pin and the second pin of the first optocoupler is 0.7V, and the conduction voltage value between the first pin and the second pin of the second optocoupler is 0.7V.

[0047] Implementing the over-voltage and under-voltage protection circuit of the present utility model, by setting an under-voltage detection module and an over-voltage detection module, when detecting power supply under-voltage or over-voltage, the power supply voltage output is prohibited, effectively protecting the circuit components. The circuit structure is simple, reducing the cost of the product's protection circuit and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0049] Figure 1 is a schematic diagram of the module connection of the over-voltage and under-voltage protection circuit in the present utility model;

[0050] Figure 2 is a schematic diagram of the module connection of the under-voltage detection module in the present utility model;

[0051] Figure 3 is a schematic diagram of the module connection of the over-voltage detection module in the present utility model;

[0052] Figure 4 is a schematic diagram of the circuit connection of the over-voltage and under-voltage protection circuit in the present utility model;

[0053] The names of the parts referred to by each number in the drawings are: 100 - under-voltage detection module, 200 - over-voltage detection module, 300 - protection output module, 110 - first optocoupler unit, 120 - first triode unit, 210 - second optocoupler unit, 220 - second triode unit. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0054] The following will clearly and completely describe the technical solutions in the present utility model in conjunction with the accompanying drawings in the utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all embodiments. Based on the embodiments in the present utility model, other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0055] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present utility model belongs. The terms used in the description of the present utility model in this specification are only for the purpose of describing specific embodiments, and are not intended to limit the present utility model. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0056] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0057] It should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0058] In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically defined.

[0059] The existing over- and under-voltage protection circuits have the problems of using more components, relatively complex circuits, not affecting the generation efficiency, and also increasing the cost of the product.

[0060] In view of the above problems, an over- and under-voltage protection circuit is proposed.

[0061] An over- and under-voltage protection circuit, as Figure 1 , Figure 1It is a schematic diagram of module connection of the over-voltage and under-voltage protection circuit in the present utility model; it includes an under-voltage detection module 100, an over-voltage detection module 200, and a protection output module 300; the under-voltage detection module 100 is electrically connected to the over-voltage detection module 200 and the protection output module 300; the over-voltage detection module 200 is also electrically connected to the protection output module 300; the under-voltage detection module 100 is used to ground the positive power supply terminal of the relay K1 of the protection output module 300 when detecting that the power supply is under-voltage, so that the relay K1 cannot be attracted, and the power supply voltage output is prohibited; the over-voltage detection module 200 is used to ground the negative power supply terminal of the relay K1 of the protection output module 300 when detecting that the power supply is over-voltage, so that the relay K1 cannot be attracted, and the power supply voltage output is prohibited. By setting the under-voltage detection module 100 and the over-voltage detection module 200, when detecting that the power supply is under-voltage or over-voltage, the power supply voltage output is prohibited, effectively protecting the components of the circuit. The circuit structure is simple, reducing the cost of the protection circuit of the product and improving the production efficiency.

[0062] Further, as Figure 2 , Figure 2 It is a schematic diagram of module connection of the under-voltage detection module 100 in the present utility model; the under-voltage detection module 100 includes a first optocoupler unit 110 and a first triode unit 120; the first optocoupler unit 110 is electrically connected to the first triode unit 120; the first optocoupler unit 110 is used to output a high level to the first triode unit 120 when detecting that the power supply voltage is under-voltage.

[0063] Specifically, as Figure 4 , Figure 4 It is a schematic diagram of circuit connection of the over-voltage and under-voltage protection circuit in the present utility model; the first optocoupler unit 110 includes a first optocoupler (U1A) and a first resistor R1; the first triode unit 120 includes a second resistor R2, a third resistor R3, a first capacitor C1, and a first triode Q1; the first pin (pin 1) of the first optocoupler (U1A) is connected to the power supply, the second pin (pin 2) is electrically connected to the first end of the first resistor R1, the third pin (pin 7) is electrically connected to the first end of the second resistor R2, the first end of the first capacitor C1, and the base of the first triode Q1; the second end of the first resistor R1 is grounded and electrically connected to the over-voltage detection module 200; the second end of the second resistor R2 is electrically connected to the power supply, the second end of the first capacitor C1 and the emitter of the first triode Q1 are commonly connected and then grounded; the collector of the first triode Q1 is electrically connected to the first end of the third resistor R3 and the protection output module 300; the second end of the third resistor R3 is electrically connected to the power supply.

[0064] The under-voltage detection principle in this embodiment is:

[0065] The current passes through the first pin and the second pin (pin 1 and pin 2) of the first optocoupler (U1A) and then reaches the first resistor R1, and then flows into the power ground. When the input voltage is lower than the set protection voltage, due to the function of the zener diode D3, there is no current in this branch, and the resistor R1 current branch cannot generate enough current to turn on the light-emitting diode D of the first optocoupler (U1A). At this time, the third pin (pin 7) of the first optocoupler (U1A) outputs a high level, making the first triode Q1 conduct, the positive power supply terminal of the K1 relay K1 grounded, and unable to be attracted, resulting in the output signal not being connected, playing a protective role.

[0066] Further, as Figure 3 , Figure 3 is a schematic diagram of the module connection of the overvoltage detection module 200 in the present invention; the overvoltage detection module 200 includes a second optocoupler unit 210 and a second triode unit 220; the second optocoupler unit 210 is electrically connected to the second triode unit 220; the second optocoupler unit 210 is used to output a low level to the second triode unit 220 when detecting that the power supply voltage is overvoltage.

[0067] Specifically, as Figure 4 , the second optocoupler unit 210 includes a first diode D1, a first zener diode D3, a fourth resistor R4 and a second optocoupler (U1B); the second triode unit 220 includes: the second triode unit 220 includes a fifth resistor R5, a second capacitor C2 and a second triode Q2; the anode of the first diode D1 is electrically connected to the first end of the first resistor R1 and the second pin (pin 2) of the first optocoupler, and the cathode is electrically connected to the first end of the fourth resistor R4. The second end of the fourth resistor R4 is electrically connected to the first pin (pin 4) of the second optocoupler (U1B); the anode of the first zener diode D3 is electrically connected to the second end of the first resistor R1, and the cathode is electrically connected to the second pin (pin 3) of the second optocoupler (U1B); the third pin (pin 6) of the second optocoupler (U1B) is electrically connected to the first end of the fifth resistor R5, the first end of the second capacitor C2 and the base of the second triode Q2; the second end of the fifth resistor R5 is connected to the power supply, and the second end of the second capacitor C2 and the emitter of the second triode Q2 are commonly connected and then grounded; the collector of the second triode Q2 is electrically connected to the protection output module 300.

[0068] Overvoltage principle in this embodiment: When the voltage exceeds the protection voltage set by the circuit, at this time, enough current flows through the current branch of the first resistor R1 to turn on the light-emitting diode D of the first optocoupler (U1A). At this time, the third pin (pin 7) of the first optocoupler (U1A) outputs a low level, causing the first triode Q1 to cut off. The positive power supply terminal of the relay K1 is connected. Since the voltage is sufficient to turn on the D3 branch, the light-emitting diode D of the second optocoupler (U1B) is turned on at this time. The third pin (pin 6) of the second optocoupler (U1B) outputs a low level, causing the second triode Q2 to cut off, the negative power supply terminal of the K1 relay to be cut off, and it cannot be attracted, resulting in the output signal not being connected, playing a protective role.

[0069] Specifically, the protection output module 300 includes a second diode D2 and a relay K1. The cathode of the second diode D2 is electrically connected to the first end of the third resistor R3, the positive power supply terminal of the relay K1, and the collector of the first triode Q1. The anode of the second diode D2 is electrically connected to the negative power supply terminal of the relay K1 and the collector of the second triode Q2.

[0070] Preferably, the conduction voltage value between the first pin and the second pin of the first optocoupler is 0.7V, and the conduction voltage value between the first pin and the second pin of the second optocoupler is 0.7V.

[0071] Implementing the over- and under-voltage protection circuit of the present utility model, by setting the under-voltage detection module 100 and the over-voltage detection module 200, when detecting power supply under-voltage or over-voltage, the power supply voltage output is prohibited, effectively protecting the components of the circuit. The circuit structure is simple, reducing the cost of the protection circuit of the product and improving the production efficiency.

[0072] The above is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. An over-voltage and under-voltage protection circuit, characterized in that: include: Undervoltage detection module; Overvoltage detection module; Protect output modules; The undervoltage detection module is electrically connected to the overvoltage detection module and the protection output module; The overvoltage detection module is also electrically connected to the protection output module; The undervoltage detection module is used to ground the positive power supply terminal of the relay of the protection output module when detecting the power supply undervoltage, so that the relay cannot be attracted and the power supply voltage output is prohibited; The overvoltage detection module is used to ground the negative power supply terminal of the relay of the protection output module when detecting power supply overvoltage, so that the relay cannot be attracted and the power supply voltage output is prohibited.

2. The over-voltage and under-voltage protection circuit according to claim 1, characterized in that: The undervoltage detection module comprises: A first optical coupling unit; The first triode unit; The first optical coupling unit is electrically connected to the first triode unit; The first optical coupling unit is used to output a high level to the first transistor unit when detecting that the power supply voltage is undervoltage.

3. The over-voltage and under-voltage protection circuit according to claim 2, characterized in that: The overvoltage detection module comprises: A second optical coupling unit; The second triode unit; The second optical coupling unit is electrically connected to the second triode unit; The second optical coupling unit is used for outputting a low level to the second transistor unit when detecting an overvoltage of the power supply voltage.

4. The over-voltage and under-voltage protection circuit according to claim 3, characterized in that: The first optical coupling unit comprises: A first optocoupler and a first resistor; The first triode unit comprises: A second resistor, a third resistor, a first capacitor and a first transistor; The first pin of the first optocoupler is connected to a power supply, the second pin is electrically connected to the first end of the first resistor, and the third pin is electrically connected to the first end of the second resistor, the first end of the first capacitor, and the base of the first transistor; The second end of the first resistor is grounded and electrically connected to the overvoltage detection module; The second end of the second resistor is electrically connected to a power supply, and the second end of the first capacitor is connected to the emitter of the first transistor and then to ground; The collector of the first transistor is electrically connected to the first end of the third resistor and the protection output module; The second end of the third resistor is electrically connected to a power source.

5. The over-voltage and under-voltage protection circuit according to claim 4, characterized in that: The second optical coupling unit includes a first diode, a first voltage regulator diode, a fourth resistor and a second optical coupler; the second transistor unit includes: The second triode unit includes a fifth resistor, a second capacitor and a second triode; The anode of the first diode is electrically connected to the first end of the first resistor and the second pin of the first optocoupler, the cathode is electrically connected to the first end of the fourth resistor, and the second end of the fourth resistor is electrically connected to the first pin of the second optocoupler; The anode of the first voltage stabilizing diode is electrically connected to the second end of the first resistor, and the cathode is electrically connected to the second pin of the second optocoupler; The third pin of the second optical coupler is electrically connected to the first end of the fifth resistor, the first end of the second capacitor and the base of the second transistor; The second end of the fifth resistor is connected to a power supply, and the second end of the second capacitor is connected to the emitter of the second transistor and then to ground; The collector of the second transistor is electrically connected to the protection output module.

6. The over-voltage and under-voltage protection circuit according to claim 5, characterized in that: The protection output module comprises: A second diode; Relay; The cathode of the second diode is electrically connected to the first end of the third resistor, the positive power supply terminal of the relay and the collector of the first transistor; The anode of the second diode is electrically connected to the negative power supply terminal of the relay and the collector of the second transistor.

7. The over-voltage and under-voltage protection circuit according to claim 6, characterized in that: The conduction voltage value between the first pin and the second pin of the first optocoupler is 0.7V, and the conduction voltage value between the first pin and the second pin of the second optocoupler is 0.7V.

Images