Discharge circuit and discharge device

Abstract

The utility model relates to a discharging circuit and a discharging device. A polarity fixing circuit in the discharging circuit carries out polarity fixing on an electric signal which is connected to an input end and comes from a to-be-discharged device and then outputs the electric signal; the consumption circuit consumes the electric energy output by the polarity fixed circuit in a mode of constant current or taking the constant current as a target, so that equipment damage caused by excessive instantaneous discharge current can be avoided.

Description

Technical Field

[0001] This application belongs to the field of electronic circuit technology, and in particular relates to a discharge circuit and a discharge device. Background Technology

[0002] Conventional discharge pens lack control over the discharge current and use multi-stage Zener diodes to drive the discharge through a skip-breakdown process, which can easily lead to excessive instantaneous discharge current. Utility Model Content

[0003] The purpose of this application is to provide a discharge circuit and discharge device that aims to solve the problem that conventional discharge methods lack control over the discharge current.

[0004] In a first aspect, embodiments of this application provide a discharge circuit, including:

[0005] The input terminal is used for electrical connection to the device to be discharged.

[0006] A polarity fixing circuit, connected to the input terminal, is configured to fix the polarity of the electrical signal input to the input terminal before outputting it.

[0007] The power consumption circuit is connected to the output of the polarity fixed circuit and is configured to operate in a constant current or constant current-target manner to consume the electrical energy output by the polarity fixed circuit.

[0008] In some embodiments, the power consumption circuit includes a power consumption loop and a feedback circuit. After the power consumption loop is coupled to the feedback circuit, it is connected between the positive and negative output terminals of the polarity fixed circuit. The power consumption loop is used to consume the electrical energy output by the polarity fixed circuit, and the feedback circuit is used to configure the power consumption loop to operate in a constant current state or with constant current as the target.

[0009] In some embodiments, the consumption circuit includes: a first bias circuit, a load circuit, and a first switching circuit;

[0010] The first terminal of the first bias circuit is connected to the first output electrode of the polarity-fixed circuit, the second terminal of the first bias circuit is connected to the control terminal of the first switching circuit and the first terminal of the feedback circuit, the first terminal of the first switching circuit is connected to the first output electrode of the polarity-fixed circuit through the load circuit, and the second terminal of the first switching circuit is connected to the second terminal of the feedback circuit. The first bias circuit is used to provide a first bias voltage to the control terminal of the first switching circuit to turn on the first switching circuit. The load circuit is used to consume the electrical energy output by the polarity-fixed circuit when the first switching circuit is turned on. The first output electrode of the polarity-fixed circuit is either the positive output electrode or the negative output electrode.

[0011] In some embodiments, the feedback circuit includes a second bias circuit and a second switching circuit. The first terminal of the second bias circuit constitutes the second terminal of the feedback circuit and is connected to the second terminal of the first switching circuit and the control terminal of the second switching circuit. The first terminal of the second switching circuit constitutes the first terminal of the feedback circuit. The second terminal of the second bias circuit and the second terminal of the second switching circuit are connected to the second output electrode of the polarity-fixed circuit. The second bias circuit is used to provide a second bias voltage to the control terminal of the second switching circuit. In this embodiment, one of the first output electrode and the second output electrode of the polarity-fixed circuit is a positive output electrode and the other is a negative output electrode.

[0012] In some embodiments, the first bias circuit includes a bias resistor, the first switching circuit includes a first semiconductor switch, the second switching circuit includes a second semiconductor switch, and the second bias circuit includes a first voltage divider resistor.

[0013] The first end of the bias resistor is connected to the positive output of the polarity-fixed circuit, and the second end of the bias resistor is connected to the control electrode of the first semiconductor switch and the first end of the feedback circuit. The first conducting electrode of the first semiconductor switch is connected to the positive output of the polarity-fixed circuit through the load circuit, and the second conducting electrode of the first semiconductor switch is connected to the second end of the feedback circuit. The first end of the first voltage divider resistor is connected to the second conducting electrode of the first semiconductor switch and the control electrode of the second semiconductor switch. The first conducting electrode of the second semiconductor switch constitutes the first end of the feedback circuit, and the second end of the first voltage divider resistor and the second conducting electrode of the second semiconductor switch are connected to the negative output of the polarity-fixed circuit. Or

[0014] The first end of the bias resistor is connected to the negative output of the polarity-fixed circuit, and the second end of the bias resistor is connected to the control electrode of the first semiconductor switch and the first end of the feedback circuit. The first conducting electrode of the first semiconductor switch is connected to the negative output of the polarity-fixed circuit through the load circuit, and the second conducting electrode of the first semiconductor switch is connected to the second end of the feedback circuit. The first end of the first voltage divider resistor is connected to the second conducting electrode of the first semiconductor switch and the control electrode of the second semiconductor switch. The first conducting electrode of the second semiconductor switch constitutes the first end of the feedback circuit, and the second end of the first voltage divider resistor and the second conducting electrode of the second semiconductor switch are connected to the positive output of the polarity-fixed circuit.

[0015] In some embodiments, the feedback circuit is also used to limit the operating current of the consumption circuit.

[0016] In some embodiments, the feedback circuit includes a positive temperature coefficient thermistor, which is connected in series with the second terminal of the second switching circuit and the first terminal of the second bias circuit, and the positive temperature coefficient thermistor is thermally coupled to the first switching circuit.

[0017] In some embodiments, the consumption circuit further includes a voltage regulator circuit connected to the control terminal of the first switching circuit for limiting the voltage of the first switching circuit.

[0018] In some embodiments, the input terminals of the discharge circuit include a first input terminal and a second input terminal, wherein the first input terminal is used to be electrically connected to the first electrode of the device to be discharged, and the second input terminal is used to be electrically connected to the second electrode of the device to be discharged.

[0019] In some embodiments, the polarity fixing circuit includes a rectifier bridge, the first input terminal and the second input terminal of the rectifier bridge are respectively connected to the first input terminal and the second input terminal, and the positive output terminal and the negative output terminal of the rectifier bridge are respectively used as the positive output terminal and the negative output terminal of the polarity fixing circuit.

[0020] In some embodiments, a polarity indicator circuit is further included, which is connected between one of the first input terminal and the second input terminal and the polarity fixing circuit, and is used to indicate the polarity of the electrical signal connected to the input terminal.

[0021] In some embodiments, the polarity indicator circuit includes a first conducting branch, a second conducting branch, and an indicator circuit. The first conducting branch and the second conducting branch are connected in parallel in reverse and then connected in series between the input terminal and the polarity fixing circuit. The indicator circuit is connected to the first conducting branch and the second conducting branch.

[0022] In some embodiments, the first conducting branch includes at least one first diode, the second conducting branch includes at least one second diode, and the indicating circuit includes a first light-emitting device with the same conducting direction as the at least one first diode and a second light-emitting device with the same conducting direction as the at least one second diode;

[0023] The at least one first diode is connected in series or in parallel with the first light-emitting device in the same direction, and then connected between the input terminal and the polarity fixing circuit.

[0024] The at least one second diode is connected in series or in parallel with the second light-emitting device in the same direction, and then connected between the input terminal and the polarity fixing circuit.

[0025] In some embodiments, an input protection circuit is further included, which is connected to the input terminal and is used for overcurrent or short-circuit protection.

[0026] In some embodiments, the input protection circuit includes a fuse and a resistor, the resistor being connected between the first input terminal and the second input terminal, and the fuse being connected between one of the first input terminal and the second input terminal and the resistor.

[0027] Secondly, embodiments of this application also provide a discharge device comprising:

[0028] The gripping part, wherein the discharge circuit described above is disposed;

[0029] An extension portion is fixedly connected to the grip portion, and the extension portion is provided with conductive lines;

[0030] A discharge probe is fixed to the end of the extension away from the gripping part and is electrically connected to the input terminal of the discharge circuit through the conductive line.

[0031] In some embodiments, the discharge probe is retractable.

[0032] In some embodiments, the extension may be elastically bent.

[0033] In some embodiments, the number of extensions is two, and each extension is provided with a discharge probe.

[0034] The advantages of the embodiments in this application compared with related technologies are:

[0035] The discharge circuit provided in this application embodiment has a polarity fixing circuit that fixes the polarity of the electrical signal from the device to be discharged input to the input terminal before outputting it; the power dissipation circuit operates in a constant current or constant current-target mode to dissipate the electrical energy output by the polarity fixing circuit, which can avoid damage to the device caused by excessive instantaneous discharge current. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of a discharge circuit provided in an embodiment of this application;

[0037] Figure 2 This is a schematic diagram of the structure of a discharge circuit provided in an embodiment of this application;

[0038] Figure 3 Example circuit diagram of a discharge circuit provided in an embodiment of this application;

[0039] Figure 4 Example circuit diagram of a discharge circuit provided in an embodiment of this application;

[0040] Figure 5 Example circuit diagram of a discharge circuit provided in an embodiment of this application;

[0041] Figure 6 Example circuit diagram of a discharge circuit provided in an embodiment of this application;

[0042] Figure 7 Example circuit diagram of the polarity indicator circuit in a discharge circuit provided in an embodiment of this application;

[0043] Figure 8 This is a schematic diagram of the structure of a discharge device provided in an embodiment of this application. Detailed Implementation

[0044] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0045] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0046] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0047] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0048] Please see Figure 1 One embodiment of this application provides a discharge circuit including an input terminal 11, a polarity fixing circuit 12, and a consumption circuit 13.

[0049] Input terminal 11 is used to electrically connect to the device to be discharged 100; polarity fixing circuit 12 is connected to input terminal 11 and configured to fix the polarity of the electrical signal input to input terminal 11 before outputting; consumption circuit 13 is connected to the output of polarity fixing circuit 12 and configured to consume the electrical energy output by polarity fixing circuit 12 in a constant current or constant current as the target.

[0050] The polarity fixing circuit 12 fixes the polarity of the input electrical signal by converting it into a fixed positive or negative DC output to the dissipation circuit 13, regardless of whether one end of the polarity fixing circuit 12 receives a positive or reverse voltage from the device to be discharged 100. The dissipation circuit 13 operates in a constant current mode or with constant current as its target, meaning that the operating current reaches dynamic stability to achieve constant current, thus avoiding damage to the equipment caused by excessive instantaneous discharge current.

[0051] Please see Figure 2 The consumption circuit 13 includes a consumption loop 131 and a feedback circuit 132. The consumption loop 131 and the feedback circuit 132 are coupled together.

[0052] In some embodiments, the consumption circuit 131 is connected to the positive output of the polarity fixed circuit 12 to consume the electrical energy output by the polarity fixed circuit 12; the feedback circuit 132 is coupled to the consumption circuit 131 and connected to the negative output of the polarity fixed circuit 12 to configure the consumption circuit 131 to operate in a constant current state or with constant current as the target.

[0053] In some embodiments, the consumption circuit 131 is connected to the negative output of the polarity fixed circuit 12 to consume the electrical energy output by the polarity fixed circuit 12; the feedback circuit 132 is coupled to the consumption circuit 131 and connected to the positive output of the polarity fixed circuit 12 to configure the consumption circuit 131 to operate in a constant current state or with constant current as the target.

[0054] The feedback circuit 132 provides negative feedback to the consumption circuit 131, which makes the operating current of the consumption circuit 131 dynamically stable, thereby achieving constant current. That is, it operates in a constant current state or with constant current as the target, thus avoiding damage to the equipment caused by excessive instantaneous discharge current.

[0055] Please see Figures 3 to 6In some embodiments, the consumption circuit 131 includes: a first bias circuit R4, a load circuit R5, and a first switching circuit Q1. The first terminal of the first bias circuit R4 is connected to the first output electrode of the polarity-fixed circuit 12, and the second terminal of the first bias circuit R4 is connected to the control terminal of the first switching circuit Q1 and the first terminal of the feedback circuit 132. The first terminal of the first switching circuit Q1 is connected to the first output electrode of the polarity-fixed circuit 12 via the load circuit R5, and the second terminal of the first switching circuit Q1 is connected to the second terminal of the feedback circuit 132. The first bias circuit R4 provides a first bias voltage to the control terminal of the first switching circuit Q1, causing the first switching circuit Q1 to conduct. The load circuit R5 consumes the electrical energy output by the polarity-fixed circuit 12 when the first switching circuit Q1 is conducting.

[0056] Among them, the first output electrode of the polarity fixing circuit 12 is the output positive electrode (see Figure 3 and Figure 4 ) or output negative terminal (see Figure 5 and Figure 6 The first bias circuit R4 provides the first bias voltage based on the output of the polarity fixed circuit 12. It can be understood that the first bias circuit R4, the first switching circuit Q1, and the load circuit R5 all participate in consuming the electrical energy output by the fixed circuit, with the load circuit R5 consuming significantly more.

[0057] Please continue reading. Figures 3 to 6 In some embodiments, the feedback circuit 132 includes a second bias circuit R7 and a second switching circuit Q2. The first end of the second bias circuit R7 constitutes the second end of the feedback circuit 132 and is connected to the second end of the first switching circuit Q1 and the control end of the second switching circuit Q2. The first end of the second switching circuit Q2 constitutes the first end of the feedback circuit 132. The second ends of the second bias circuit R7 and the second ends of the second switching circuit Q2 are connected to the second output electrode of the polarity fixing circuit 12. The second bias circuit R7 is used to provide a second bias voltage to the control end of the second switching circuit Q2. The first output electrode and the second output electrode of the polarity fixing circuit 12 are either positive or negative.

[0058] exist Figure 3 and Figure 4 In the example, the first output electrode of the polarity-fixed circuit 12 is the positive output electrode, and the second output electrode is the negative output electrode; in Figure 5 and Figure 6 In the example, the first output electrode of the polarity-fixed circuit 12 is the negative output electrode, and the second output electrode is the positive output electrode.

[0059] In this circuit, the second bias circuit R7 divides the voltage at the second terminal of the first switching circuit Q1 to generate a second bias voltage, which is then supplied to the control terminal of the second switching circuit Q2. The magnitude of the second bias voltage can adjust the switching degree of the second switching circuit Q2, that is, it can adjust its operating current, thereby adjusting the magnitude of the first bias voltage and adjusting the operating current of the first switching circuit Q1, forming negative feedback to adjust the operating current of the first switching circuit Q1.

[0060] In some embodiments, the first bias circuit R4 includes a bias resistor, the first switching circuit Q1 includes a first semiconductor switch, the second switching circuit Q2 includes a second semiconductor switch, and the second bias circuit R7 includes a first voltage divider resistor.

[0061] exist Figure 3 and Figure 4 In the example, the first end of the bias resistor is connected to the positive output of the polarity-fixed circuit 12, the second end of the bias resistor is connected to the control electrode of the first semiconductor switch and the first end of the feedback circuit 132, the first conducting electrode of the first semiconductor switch is connected to the positive output of the polarity-fixed circuit 12 through the load circuit R5, and the second conducting electrode of the first semiconductor switch is connected to the second end of the feedback circuit 132; the first end of the first voltage divider resistor is connected to the second conducting electrode of the first semiconductor switch and the control electrode of the second semiconductor switch; the first conducting electrode of the second semiconductor switch constitutes the first end of the feedback circuit 132, and the second end of the first voltage divider resistor and the second conducting electrode of the second semiconductor switch are connected to the negative output of the polarity-fixed circuit 12.

[0062] exist Figure 5 and Figure 6 In the example, the first end of the bias resistor is connected to the negative output of the polarity-fixed circuit 12, the second end of the bias resistor is connected to the control electrode of the first semiconductor switch and the first end of the feedback circuit 132, the first conducting electrode of the first semiconductor switch is connected to the negative output of the polarity-fixed circuit 12 through the load circuit R5, and the second conducting electrode of the first semiconductor switch is connected to the second end of the feedback circuit 132; the first end of the first voltage divider resistor is connected to the second conducting electrode of the first semiconductor switch and the control electrode of the second semiconductor switch; the first conducting electrode of the second semiconductor switch constitutes the first end of the feedback circuit 132, and the second end of the first voltage divider resistor and the second conducting electrode of the second semiconductor switch are connected to the positive output of the polarity-fixed circuit 12.

[0063] The first semiconductor switch is, for example, an N-channel field-effect transistor (see Figure 3 ), NPN transistor (see) Figure 4 P-channel MOSFET (see P-channel MOSFET) Figure 5 ) or PNP transistor (see Figure 6The second semiconductor switch is, for example, an NPN transistor (see...). Figure 3 and Figure 4 ) or PNP transistor (see Figure 5 and Figure 6 The polarity-fixed circuit 12 can be a rectifier bridge (see...). Figure 3 , Figure 5 and Figure 6 It can also be a rectifier circuit consisting of 4 diodes (see...). Figure 4 ).

[0064] Combination Figures 1 to 6 When the device to be discharged 100 is discharged, the first switching circuit Q1 is turned on under the action of the first bias circuit R4. The discharge current passes through the load circuit R5 and the first switching circuit Q1, and then through the second bias circuit R7 to generate a voltage drop to provide bias for the second switching circuit Q2. When the voltage drop is greater than the conduction voltage of the second switching circuit Q2, the second switching circuit Q2 will turn on, pulling down the gate voltage of the first switching circuit Q1. The current flowing through the first switching circuit Q1 will decrease. After the discharge current decreases, the voltage drop on the second bias circuit R7 also decreases, causing the voltage on the base of the second switching circuit Q2 to also decrease. The conduction degree of the second switching circuit Q2 also decreases. After the conduction degree of the second switching circuit Q2 decreases, the gate voltage of the first switching circuit Q1 is pulled up again by the first bias circuit R4, the conduction degree of the first switching circuit Q1 increases, the current flowing through the first switching circuit Q1 increases, and the conduction degree of the first switching circuit Q1 is limited by the second switching circuit Q2, generating a negative feedback effect. The current reaches dynamic stability, thereby achieving constant current.

[0065] In some embodiments, the feedback circuit 132 is also used to limit the operating current of the consumption circuit. For example, the feedback circuit 132 is further provided with a temperature compensation device and a voltage or current limiting device to provide a certain inverse proportional limit based on the magnitude of the operating current of the consumption circuit.

[0066] Please continue reading. Figures 3 to 6 In some embodiments, the feedback circuit 132 includes a positive temperature coefficient thermistor (PTC) TR1, which is connected in series with the second terminal of the second switching circuit Q2 and the first terminal of the second bias circuit R7, and the positive temperature coefficient thermistor TR1 is thermally coupled to the first switching circuit Q1.

[0067] In this embodiment, the positive temperature coefficient thermistor TR1 is close to the pins of the field-effect transistor of the first switching circuit Q1, the device body, and the load circuit R5. When the current flowing through the positive temperature coefficient thermistor TR1 increases, causing the temperature to rise, or when the temperature of the field-effect transistor of the first switching circuit Q1 and the load circuit R5 rises, the resistance of the positive temperature coefficient thermistor TR1 increases. The voltage drop across the positive temperature coefficient thermistor TR1 and the second bias circuit R7 increases when the initial current of the same magnitude flows through the second bias circuit R7. The conduction degree of the second switching circuit Q2 increases, pulling down the gate potential of the field-effect transistor of the first switching circuit Q1. This results in a decrease in the conduction degree of the field-effect transistor of the first switching circuit Q1, thereby reducing the discharge current and protecting the field-effect transistor of the first switching circuit Q1 from overload hazards.

[0068] In this embodiment, the discharge current limit can be adjusted by the feedback circuit 132. In related technologies, in high-voltage discharge applications such as 400V switching power supplies, a kiloohm-level resistor close to the input terminal 11 is required to achieve safe and effective current limiting. However, in low-voltage discharge applications, the discharge time is greatly extended due to the excessively large kiloohm-level resistor at the input terminal 11, making it impossible to effectively satisfy discharge requirements under both high and low voltage conditions simultaneously. In this embodiment, the discharge current is adjusted by the feedback circuit 132 to effectively satisfy discharge requirements under both high and low voltage conditions.

[0069] Please continue reading. Figures 3 to 6 In some embodiments, the consumption circuit 131 further includes a voltage regulator circuit connected to the control terminal of the first switching circuit Q1. This voltage regulator circuit limits the voltage at the control terminal of the first switching circuit Q1, i.e., limits its maximum on-state voltage, thus protecting the first switching circuit Q1. The voltage regulator circuit includes a Zener diode ZD1. In some examples, the anode and cathode of the Zener diode ZD1 are connected to the control terminal and the second terminal of the first switching circuit Q1, respectively. See [reference needed]. Figure 3 and Figure 4 In some examples, the anode and cathode of the Zener diode ZD1 are connected to the second terminal and control terminal of the first switching circuit Q1, respectively. See [reference needed]. Figure 5 and Figure 6 .

[0070] In some embodiments, it is understood that the input terminal 11 of the discharge circuit may include one input terminal or two input terminals. When the input terminal 11 of the discharge circuit includes one input terminal, it can be connected to the positive terminal of the device to be discharged 100, while the consumption circuit 13 / polarity fixing circuit 12 can be connected to the negative terminal of the device to be discharged 100, or the negative terminal of the circuit in which it is located, to form a discharge working circuit.

[0071] Please continue reading. Figures 3 to 6In some embodiments, the input terminal 11 of the discharge circuit includes a first input terminal T1 and a second input terminal T2. The first input terminal T1 is used to be electrically connected to the first electrode of the device to be discharged 100, and the second input terminal T2 is used to be electrically connected to the second electrode of the device to be discharged 100.

[0072] When the input terminal 11 of the discharge circuit includes two input terminals, the consumption circuit can be set independently. For example, the first input terminal T1 and the second input terminal T2 can be connected to two discharge probes respectively, which will contact the two poles of the device to be discharged 100 respectively.

[0073] Please continue reading. Figures 3 to 6 In some embodiments, the polarity-fixed circuit 12 includes a rectifier bridge D7. The first input terminal 11 and the second input terminal 11 of the rectifier bridge D7 are respectively connected to the first input terminal T1 and the second input terminal T2. The positive and negative output terminals of the rectifier bridge D7 serve as the positive and negative output terminals of the polarity-fixed circuit 12, respectively. The rectifier bridge D7 converts a voltage of unknown polarity into a fixed polarity for discharging into the consumption circuit 13.

[0074] Please continue reading. Figures 3 to 6 In some embodiments, the discharge circuit further includes a polarity indicator circuit 14, which is connected between one of the two first input terminals T1 and the second input terminal T2 and the polarity fixing circuit 12. The polarity indicator circuit 14 is used to indicate the polarity of the electrical signal connected to the input terminal 11, adding a prompting function so that the operator knows which is the positive terminal and which is the negative terminal, which facilitates maintenance or debugging.

[0075] In some embodiments, the polarity indicator circuit 14 includes a first conducting branch 141, a second conducting branch 142, and an indicator circuit. The first conducting branch 141 and the second conducting branch 142 are connected in reverse parallel and then connected in series between the input terminal 11 and the polarity fixing circuit 12. The indicator circuit is connected in parallel or in series with the first conducting branch 141 and the second conducting branch 142.

[0076] For example, the first input terminal T1 and the second input terminal T2 are connected to the positive and negative terminals of the device to be discharged 100, respectively. The first conducting branch 141 is turned on to supply power to the indicator circuit, thereby indicating that the two input terminals are connected to the electrodes of the device to be discharged 100 in the positive direction at this time. The first input terminal T1 and the second input terminal T2 are connected to the negative and positive terminals of the device to be discharged 100, respectively. The second conducting branch 142 is turned on to supply power to the indicator circuit, thereby indicating that the two input terminals are connected to the electrodes of the device to be discharged 100 in the reverse direction at this time.

[0077] In some embodiments, the first conducting branch 141 includes at least one first diode, the second conducting branch 142 includes at least one second diode, and the indicating circuit includes a first light-emitting device with the same conduction direction as at least one first diode and a second light-emitting device with the same conduction direction as at least one second diode.

[0078] At least one first diode is connected in parallel with the first light-emitting device in the same direction and then connected between the input terminal 11 and the polarity fixing circuit 12; at least one second diode is connected in parallel with the second light-emitting device in the same direction and then connected between the input terminal 11 and the polarity fixing circuit 12.

[0079] Figures 3 to 6 In the example shown, the first conducting branch 141 includes three first diodes D1 to D3, and the second conducting branch 142 includes three second diodes D4 to D6. The first light-emitting devices include LED-RED1 and LED-BLUE2, and the second light-emitting devices include LED-RED2 and LED-BLUE1.

[0080] For example, it also includes current-limiting resistors R2 and R3. The current-limiting resistors R2 and R3, along with first diodes D1-D3 and second diodes D4-D6 that generate a fixed voltage drop, constitute the circuit. LED-RED1 and LED-RED2 are red LEDs, and LED-BLUE1 and LED-BLUE2 are blue LEDs. When the first input terminal T1 contacts the positive terminal of the device to be discharged 100, and the second input terminal T2 contacts the negative terminal of the device to be discharged 100, current flows through the first diodes D1-D3. Since the voltage drop generated when the first diodes D1-D3 are forward-biased remains essentially constant, a fixed voltage will be generated across the first diodes D1-D3. The polarity of this voltage is positive on the left side and negative on the right side of the first diodes D1-D3. At this time, LED-RED1 and LED-BLUE2 are forward-biased and emit light. When the second input terminal T2 contacts the positive terminal of the device to be discharged 100 and the first input terminal T1 contacts the negative terminal of the device to be discharged 100, current flows through the second diodes D4 to D6 and they conduct to generate a voltage drop. The polarity of this voltage is that the left side of the second diodes D4 to D6 is negative and the right side is positive. At this time, the light-emitting diodes LED-RED2 and LED-BLUE1 are forward-biased and emit light.

[0081] Please see Figure 7 In some embodiments, at least one first diode and a first light-emitting device are connected in series in the same direction between the input terminal 11 and the polarity fixing circuit 12, and at least one second diode and a second light-emitting device are connected in series in the same direction between the input terminal 11 and the polarity fixing circuit 12.

[0082] Figure 7In the example, the first conducting branch 141 includes three first diodes D1 to D3, and the second conducting branch 142 includes three second diodes D4 to D6. The first light-emitting device includes a light-emitting diode LED5, and the second light-emitting device includes a light-emitting diode LED6. When the first input terminal T1 contacts the positive terminal of the device to be discharged 100, and the second input terminal T2 contacts the negative terminal of the device to be discharged 100, current flows through the first diodes D1 to D3, and the light-emitting diode LED5 is forward-biased and emits light. When the first input terminal T1 contacts the negative terminal of the device to be discharged 100, and the second input terminal T2 contacts the positive terminal of the device to be discharged 100, current flows through the second diodes D4 to D6, and the light-emitting diode LED6 is forward-biased and emits light.

[0083] Please continue reading. Figures 3 to 6 In some embodiments, the discharge circuit further includes an input protection circuit 15, which is connected to the input terminal 11 and is used for overcurrent or short-circuit protection.

[0084] In some embodiments, the input protection circuit 15 includes a fuse F1 and a resistor R1, wherein the resistor R1 is connected between the first input terminal T1 and the second input terminal T2, and the fuse F1 is connected between one of the first input terminal T1 and the second input terminal T2 and the resistor R1.

[0085] The first input terminal T1 and the second input terminal T2 are respectively connected to the two electrodes of the device to be discharged 100. The current first flows through the fuse F1 and the resistor R1. In the event of a short circuit due to a failure of the polarity fixing circuit 12 or the consumption circuit 13, the fuse F1 can quickly melt to provide protection and prevent the device from exploding. The high-value resistor R1 ensures that the device to be discharged 100 can still discharge even if the polarity fixing circuit 12 or the consumption circuit 13 fails, preventing the user from being electrocuted when it is uncertain whether the discharge is complete.

[0086] Please see Figure 8 Secondly, one embodiment of this application also provides a discharge device including: a gripping portion 210, an extension portion 220, and a discharge probe 230.

[0087] The discharge circuit described above is provided in the gripping part 210; the extension part 220 is fixedly connected to the gripping part 210, and the extension part 220 is provided with a conductive line PCB2; the discharge probe 230 is fixed at the end of the extension part 220 away from the gripping part 210, and is electrically connected to the input terminal 11 of the discharge circuit through the conductive line PCB2.

[0088] In some embodiments, the discharge probe 230 is retractable.

[0089] In some embodiments, the extension 220 is elastically bendable.

[0090] In some embodiments, there are two extensions 220, and each extension 220 is provided with a discharge probe 230. The discharge probe 230 includes a first discharge probe TZ1 and a second discharge probe TZ2.

[0091] For example, the discharge device has a structure shaped like tweezers, is very small and suitable for carrying during electrical repairs, is ergonomic, and is used in the same way as tweezers, making it very convenient to quickly and easily adjust the probe spacing to accommodate capacitors with different pin spacings for discharge.

[0092] All discharge circuits are soldered onto a main board of the gripping part 210. Two conductive lines PCB2 are then soldered onto the main board. The conductive lines PCB2 can also be formed by copper plating on a circuit board. The ends of the two conductive lines PCB2 are then soldered with a first discharge probe TZ1 and a second discharge probe TZ2, respectively. The first discharge probe TZ1 and the second discharge probe TZ2 are, for example, retractable standard probes with disc teeth.

[0093] During discharge, the device to be discharged 100 (e.g., a capacitor) is held like a pair of tweezers. Two slender circuit boards, each forming a conductive line (PCB2), possess good flexibility and can undergo recoverable elastic bending deformation over a considerable distance. The distance between the first discharge probe TZ1 and the second discharge probe TZ2 can be adjusted by pressing with a finger to accommodate capacitors with various pin pitches. After adjusting the distance between the first discharge probe TZ1 and the second discharge probe TZ2 to contact the pins of the device to be discharged 100, a slight press is applied to achieve good contact and discharge. The retractable standard probes with disc teeth effectively contact and fix capacitors with pins of different thicknesses, preventing slippage and poor contact.

[0094] Furthermore, at both ends of the two elongated circuit boards PCB2 on the gripping part 210, which respectively form two conductive lines, are placed LED light groups consisting of red and blue LEDs. One group includes LED-RED1 and LED-RED2, and the other group includes LED-BLUE2 and LED-BLUE1. When the first discharge probe TZ1 contacts the positive terminal of the device to be discharged 100 and the second discharge probe TZ2 contacts the negative terminal of the device to be discharged 100, the red LED-RED1 lights up to indicate that the first discharge probe TZ1 is in contact with the positive terminal of the device to be discharged 100, and the blue LED-BLUE2 lights up to indicate that the second discharge probe TZ2 is in contact with the negative terminal of the device to be discharged 100. When the second discharge probe TZ2 contacts the positive terminal of the device to be discharged 100 and the first discharge probe TZ1 contacts the negative terminal of the device to be discharged 100, the red light-emitting diode LED-RED2 lights up to indicate that the second discharge probe TZ2 is in contact with the positive terminal of the device to be discharged 100, and the blue light-emitting diode LED-BLUE1 lights up to indicate that the first discharge probe TZ1 is in contact with the negative terminal of the device to be discharged 100.

[0095] The two slender circuit boards of PCB2, which form two conductive lines respectively, are wrapped with thickened, transparent, high-voltage heat-shrink tubing to isolate people's hands from the live circuit and prevent electric shock hazards. At the same time, the red and blue LEDs can illuminate through the transparent tubing to indicate polarity.

[0096] The advantages of the embodiments in this application compared with related technologies are:

[0097] The discharge circuit provided in this application uses a constant current discharge mode and adjusts the current magnitude through a negative feedback mechanism. It has an overcurrent protection function to avoid sudden and unstable discharge current and prevent damage to the capacitor and the discharger.

[0098] The feedback circuit 132 uses a positive temperature coefficient thermistor TR1, which has over-temperature protection. In the feedback circuit 132, the positive temperature coefficient thermistor TR1 is used to detect current and temperature. Its intrinsic resistance can be very small and has no effect on the discharge time. It can quickly discharge at a constant current, whether it is high voltage or low voltage, large current discharge or small current discharge.

[0099] The polarity indicator circuit 14 is powered by the voltage drop of the first diode group D1 to D3 or the second diode group D4 to D6 when they are forward-biased. The first diode group D1 to D3 and the second diode group D4 to D6 are ordinary diodes. Compared with the power supply of Zener diodes with smaller conduction current, ordinary diodes have stable voltage when forward-biased. Moreover, ordinary diodes are small in size and can have a large forward conduction current, which can reach several amperes or more. They can meet the needs of various discharge current sizes without worrying about damage.

[0100] Before the current flows through the polarity indicator circuit 14 and the polarity fixing circuit 12, it must first pass through the fuse F1. When the rectifier bridge D7 or the polarity fixing circuit 12 fails and causes a short circuit, the fuse F1 can quickly blow to provide protection and prevent the current from being too large and causing danger during a short circuit.

[0101] During discharge, the current needs to pass through semiconductor devices: polarity indicator circuit 14, rectifier bridge D7, and field-effect transistor. The voltage across the device to be discharged 100 must be greater than the forward voltage drop of these semiconductor devices for discharge to occur. Therefore, a residual voltage of several volts to ten volts will remain on the device to be discharged 100 and cannot be completely discharged. This voltage will not cause any harm to the human body, but in circuits where the residual voltage of the capacitor is critical, such as those requiring high residual voltage, additional handling is necessary. This embodiment adds a high-value resistor R1 of several hundred kiloohms directly connected in parallel to the two probes. After the discharge circuit stops discharging, resistor R1 continues to discharge, completely releasing the voltage on the capacitor. Simultaneously, when the discharge circuit fails and becomes open-circuited, resistor R1 can act as a backup discharge circuit.

[0102] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A discharge circuit, characterized in that, include: The input terminal is used for electrical connection to the device to be discharged. A polarity fixing circuit, connected to the input terminal, is configured to fix the polarity of the electrical signal input to the input terminal before outputting it. The power consumption circuit is connected to the output of the polarity fixed circuit and configured to operate in a constant current or constant current-target manner to consume the electrical energy output by the polarity fixed circuit.

2. The discharge circuit as described in claim 1, characterized in that, The power consumption circuit includes a power consumption loop and a feedback circuit. After the power consumption loop and the feedback circuit are coupled together, they are connected between the positive and negative output terminals of the polarity fixed circuit. The power consumption loop is used to consume the electrical energy output by the polarity fixed circuit. The feedback circuit is used to configure the power consumption loop to operate in a constant current state or with constant current as the target.

3. The discharge circuit as described in claim 2, characterized in that, The consumption circuit includes: a first bias circuit, a load circuit, and a first switching circuit; The first terminal of the first bias circuit is connected to the first output electrode of the polarity-fixed circuit, the second terminal of the first bias circuit is connected to the control terminal of the first switching circuit and the first terminal of the feedback circuit, the first terminal of the first switching circuit is connected to the first output electrode of the polarity-fixed circuit through the load circuit, and the second terminal of the first switching circuit is connected to the second terminal of the feedback circuit. The first bias circuit is used to provide a first bias voltage to the control terminal of the first switching circuit to turn on the first switching circuit. The load circuit is used to consume the electrical energy output by the polarity-fixed circuit when the first switching circuit is turned on. The first output electrode of the polarity-fixed circuit is either the positive output electrode or the negative output electrode.

4. The discharge circuit as described in claim 3, characterized in that, The feedback circuit includes a second bias circuit and a second switching circuit. The first end of the second bias circuit constitutes the second end of the feedback circuit and is connected to the second end of the first switching circuit and the control end of the second switching circuit. The first end of the second switching circuit constitutes the first end of the feedback circuit. The second end of the second bias circuit and the second end of the second switching circuit are connected to the second output electrode of the polarity fixed circuit. The second bias circuit is used to provide a second bias voltage to the control end of the second switching circuit. In this case, one of the first output electrode and the second output electrode of the polarity fixed circuit is a positive output electrode and the other is a negative output electrode.

5. The discharge circuit as described in claim 4, characterized in that, The first bias circuit includes a bias resistor, the first switching circuit includes a first semiconductor switching transistor, the second switching circuit includes a second semiconductor switching transistor, and the second bias circuit includes a first voltage divider resistor. The first end of the bias resistor is connected to the positive output of the polarity-fixed circuit, and the second end of the bias resistor is connected to the control electrode of the first semiconductor switch and the first end of the feedback circuit. The first conducting electrode of the first semiconductor switch is connected to the positive output of the polarity-fixed circuit through the load circuit, and the second conducting electrode of the first semiconductor switch is connected to the second end of the feedback circuit. The first end of the first voltage divider resistor is connected to the second conducting electrode of the first semiconductor switch and the control electrode of the second semiconductor switch. The first conducting electrode of the second semiconductor switch constitutes the first end of the feedback circuit, and the second end of the first voltage divider resistor and the second conducting electrode of the second semiconductor switch are connected to the negative output of the polarity-fixed circuit. Or The first end of the bias resistor is connected to the negative output of the polarity-fixed circuit, and the second end of the bias resistor is connected to the control electrode of the first semiconductor switch and the first end of the feedback circuit. The first conducting electrode of the first semiconductor switch is connected to the negative output of the polarity-fixed circuit through the load circuit, and the second conducting electrode of the first semiconductor switch is connected to the second end of the feedback circuit. The first end of the first voltage divider resistor is connected to the second conducting electrode of the first semiconductor switch and the control electrode of the second semiconductor switch. The first conducting electrode of the second semiconductor switch constitutes the first end of the feedback circuit, and the second end of the first voltage divider resistor and the second conducting electrode of the second semiconductor switch are connected to the positive output of the polarity-fixed circuit.

6. The discharge circuit as described in claim 4 or 5, characterized in that, The feedback circuit is also used to limit the operating current of the consumption circuit.

7. The discharge circuit as described in claim 6, characterized in that, The feedback circuit includes a positive temperature coefficient thermistor, which is connected in series with the second terminal of the second switching circuit and the first terminal of the second bias circuit, and the positive temperature coefficient thermistor is thermally coupled to the first switching circuit.

8. The discharge circuit as described in claim 3, characterized in that, The consumption circuit also includes a voltage regulator circuit, which is connected to the control terminal of the first switching circuit and is used to limit the voltage at the control terminal of the first switching circuit.

9. The discharge circuit as described in claim 1, characterized in that, The input terminals of the discharge circuit include a first input terminal and a second input terminal. The first input terminal is used to electrically connect to the first electrode of the device to be discharged, and the second input terminal is used to electrically connect to the second electrode of the device to be discharged.

10. The discharge circuit as described in claim 9, characterized in that, The polarity fixing circuit includes a rectifier bridge, the first input terminal and the second input terminal of the rectifier bridge are respectively connected to the first input terminal and the second input terminal, and the positive output terminal and the negative output terminal of the rectifier bridge are respectively used as the positive output terminal and the negative output terminal of the polarity fixing circuit.

11. The discharge circuit as described in claim 9 or 10, characterized in that, It also includes a polarity indicator circuit, which is connected between one of the first input terminal and the second input terminal and the polarity fixing circuit. The polarity indicator circuit is used to indicate the polarity of the electrical signal connected to the input terminal.

12. The discharge circuit as described in claim 11, characterized in that, The polarity indicator circuit includes a first conducting branch, a second conducting branch, and an indicator circuit. The first conducting branch and the second conducting branch are connected in parallel in reverse and then connected in series between the input terminal and the polarity fixing circuit. The indicator circuit is connected to the first conducting branch and the second conducting branch.

13. The discharge circuit as described in claim 12, characterized in that, The first conducting branch includes at least one first diode, the second conducting branch includes at least one second diode, and the indicating circuit includes a first light-emitting device with the same conduction direction as the at least one first diode and a second light-emitting device with the same conduction direction as the at least one second diode; The at least one first diode is connected in series or in parallel with the first light-emitting device in the same direction, and then connected between the input terminal and the polarity fixing circuit. The at least one second diode is connected in series or in parallel with the second light-emitting device in the same direction, and then connected between the input terminal and the polarity fixing circuit.

14. The discharge circuit as described in claim 9, characterized in that, It also includes an input protection circuit, which is connected to the input terminal and is used for overcurrent or short-circuit protection.

15. The discharge circuit as described in claim 14, characterized in that, The input protection circuit includes a fuse and a resistor, the resistor being connected between the first input terminal and the second input terminal, and the fuse being connected between one of the two first input terminals and the second input terminal and the resistor.

16. A discharge device, characterized in that, The discharge device includes: The gripping portion, wherein the discharge circuit as described in any one of claims 1 to 15 is disposed in the gripping portion; An extension portion is fixedly connected to the grip portion, and the extension portion is provided with conductive lines; A discharge probe is fixed to the end of the extension away from the gripping part and is electrically connected to the input terminal of the discharge circuit through the conductive line.

17. The discharge device as claimed in claim 16, characterized in that, The discharge probe is retractable.

18. The discharge device as claimed in claim 16, characterized in that, The extension is flexible and can be bent.

19. The discharge device according to any one of claims 16 to 18, characterized in that, The number of extensions is two, and each extension is provided with a discharge probe.

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