Discharge circuit and centrifuge

Abstract

The embodiment of the present invention provides a discharge circuit, comprising: a capacitor; a first discharge channel, the first discharge channel is connected in parallel to the two ends of the capacitor; and a control module, the control module is connected to the capacitor and the first discharge channel respectively, and controls the on and off of the first discharge channel; wherein the capacitor supplies power to the control module, and when the first discharge channel is turned on, the charge on the capacitor is released through the first discharge channel. The embodiment of the present invention uses the residual charge on the capacitor to provide a working voltage to the control module, so that after the power supply is turned off, the control module can still continue to work, and the first discharge channel with a small discharge time constant is controlled to be turned on, and the residual charge on the capacitor can be released through the first discharge channel. When the power supply works normally, the first discharge channel is controlled to be turned off, so that the discharge circuit has the characteristics of fast discharge speed, low ineffective power consumption, and no need for additional power supply.

Description

Technical Field

[0001] The present invention relates to the technical field of capacitor discharge, and in particular to a discharge circuit and a centrifuge. Background Art

[0002] After the circuit containing large capacitors is powered off, there is still a lot of residual electricity in the large capacitors. Especially in high-voltage circuits, the residual electricity in the large capacitors can cause harm to people who touch the circuits. Therefore, it is very necessary to quickly release the residual electricity in the large capacitors after the power is turned off.

[0003] In the prior art, a discharge resistor R is connected in parallel to a large capacitor C, and the discharge speed depends on the discharge time constant RC, that is, it is closely related to the resistance value of the discharge resistor R. If the discharge resistor R is too large, the discharge time constant will be very large, the discharge speed will not achieve the expected effect, and the discharge efficiency will be low; if the discharge resistor R is too small, the discharge time constant will become smaller, and the discharge speed will be fast, but under normal working conditions, the ineffective power consumption caused by the discharge resistor R is too large, and it is easy to cause heat dissipation problems in the circuit. Therefore, it is impossible to achieve both increasing the discharge speed and reducing the ineffective power consumption. Furthermore, the prior art uses a controller to control the on and off of the channel where the discharge resistor R is located to solve the problem that increasing the discharge speed and reducing the ineffective power consumption cannot coexist, but this requires providing an additional working voltage to the controller. Summary of the invention

[0004] The embodiment of the present invention provides a discharge circuit, aiming to solve the problem that the discharge circuit for discharging the residual electricity of a large capacitor in the prior art cannot have fast discharge speed, low invalid power consumption and no need for an additional power supply.

[0005] In a first aspect, a discharge circuit is provided, comprising:

[0006] capacitance;

[0007] a first discharge channel, the first discharge channel being connected in parallel to both ends of the capacitor; and

[0008] A control module, the control module is connected to the capacitor and the first discharge channel respectively, and controls the on and off of the first discharge channel;

[0009] The capacitor supplies power to the control module, and when the first discharge channel is turned on, the electricity on the capacitor is released through the first discharge channel.

[0010] In a second aspect, a centrifuge is provided, comprising the discharge circuit as described above.

[0011] The embodiment of the present invention utilizes the residual electricity on the capacitor to provide a working voltage to the control module, so that after the power supply is turned off, the control module can still continue to work, and the first discharge channel with a small discharge time constant is controlled to be turned on, and the residual electricity on the capacitor can be released through the first discharge channel. When the power supply works normally, the first discharge channel is controlled to be turned off, thereby realizing the characteristics of the discharge circuit having fast discharge speed, low invalid power consumption, and no need for additional power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0013] Figure 1 is a schematic diagram of a discharge circuit provided in Embodiment 1 of the present invention;

[0014] Figure 2 is a schematic diagram of another discharge circuit provided in Embodiment 1 of the present invention;

[0015] Figure 3 is a schematic diagram of a power failure detection module provided in Embodiment 1 of the present invention;

[0016] Figure 4 is a schematic diagram of a discharge circuit provided in Embodiment 2 of the present invention;

[0017] Figure 5 Schematic diagram of a discharge circuit provided in Embodiment 3 of the present invention. DETAILED DESCRIPTION

[0018] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar modules or modules with the same or similar functions. The embodiments described below by reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limitations of the present invention. On the contrary, embodiments of the present invention include all changes, modifications and equivalents that fall within the spirit and connotation of the appended claims.

[0019] The embodiment of the present invention utilizes the residual electricity on the capacitor to provide a working voltage to the control module, so that after the power supply is turned off, the control module can still continue to work, and the first discharge channel with a small discharge time constant is controlled to be turned on, and the residual electricity on the capacitor can be released through the first discharge channel. When the power supply works normally, the first discharge channel is controlled to be turned off, thereby realizing the characteristics of the discharge circuit having fast discharge speed, low invalid power consumption, and no need for additional power supply.

[0020] Embodiment 1

[0021] Figure 1 Schematic diagram of a discharge circuit provided in Embodiment 1 of the present invention. Figure 1As shown, the discharge circuit includes a large capacitor C, a first discharge channel 1 and a control module 2.

[0022] In the embodiment of the present invention, the voltage across the large capacitor C is U0, the first discharge channel 1 is connected in parallel to the two ends of the large capacitor C, and the residual electricity on the large capacitor C can be released to the ground through the first discharge channel 1 that is turned on. The control module 2 is connected to the large capacitor C and the first discharge channel 1, respectively. The residual electricity on the large capacitor C can supply power to the control module 2 and provide a working voltage for the control module 2. The control module 2 controls the on and off of the first discharge channel 1. When the first discharge channel 1 is turned on, the residual electricity on the large capacitor C is released through the first discharge channel 1.

[0023] As an embodiment of the present invention, Figure 2 As shown, the first discharge channel 1 includes a first resistor R1 and an IGBT switch (Insulated Gate Bipolar Transistor). The first end of the first resistor R1 is connected to the large capacitor C, the second end of the first resistor R1 is connected to the collector of the IGBT switch, the emitter of the IGBT switch is grounded, and the gate is connected to the control module 2. The control module 2 controls the on and off of the IGBT switch through the gate. The first discharge channel 1 can also use other path switches, which are not limited here. Since the first discharge channel 1 can release the electricity of the large capacitor C when it is turned on, the input resistance of the first discharge channel 1 when it is turned on is designed to be very small, so that its discharge time constant is small and the discharge speed is fast, and when the first discharge channel 1 is turned off, it will not cause invalid power consumption.

[0024] In an embodiment of the present invention, the discharge circuit also includes a power supply AC and a power-off detection module 3. The power supply AC is connected to the large capacitor C, and the power-off detection module 3 is connected in series between the power supply AC and the control module 2. When the power supply AC works normally, the control module 2 controls the first discharge channel 1 to be disconnected, and the power of the large capacitor C will not be released from the first discharge channel 1, and no invalid power consumption will be generated. When the power-off detection module 3 detects that the power supply AC is powered off, a power-off signal is sent to the control module 2. At the same time, the residual power on the large capacitor C supplies power to the control module 2 and the power-off detection module 3, and the control module 2 and the power-off detection module 3 can still continue to work. After receiving the power-off signal, the control module 2 controls the first discharge channel 1 to be turned on, and the power on the large capacitor C is released through the first discharge channel 1.

[0025] As an embodiment of the present invention, Figure 3As shown, the power-off detection module 3 includes an optical coupler Q, a third resistor R3, a fourth resistor R4 and a fifth resistor R5. The first end of the third resistor R3 is connected to the power supply AC, the second end of the third resistor R3 is connected to the first end of the fourth resistor R4, and the second end of the fourth resistor R4 is grounded. The first end of the optical coupler Q is connected to the second end of the third resistor R3 and the first end of the fourth resistor R4, and the third resistor R3 and the fourth resistor R4 constitute a voltage-dividing resistor; the second end of the optical coupler Q is connected to the first end of the fifth resistor R5 and the control module 2; the third end of the optical coupler Q is grounded. The second end of the fifth resistor R5 is connected to the power supply AC as a pull-up resistor. When the power supply AC is powered normally, the optical coupler Q is turned on, its second end is grounded, and the control module 2 receives a low level; when the power supply AC is powered off, the optical coupler Q is disconnected, and its second end is connected to the large capacitor C through the pull-up resistor. There is residual electricity on the large capacitor C, and the control module 2 receives a high level, which can be regarded as a power-off signal, thereby controlling the first discharge channel 1 to be turned on.

[0026] The embodiment of the present invention utilizes the residual electricity on the capacitor to provide a working voltage to the control module, so that after the power supply is turned off, the control module can still continue to work, and the first discharge channel with a small discharge time constant is controlled to be turned on, and the residual electricity on the capacitor can be released through the first discharge channel. When the power supply works normally, the first discharge channel is controlled to be turned off, thereby realizing the characteristics of the discharge circuit having fast discharge speed, low invalid power consumption, and no need for additional power supply.

[0027] Embodiment 2

[0028] Figure 4 Schematic diagram of the discharge circuit provided by the second embodiment of the present invention. Figure 4 As shown, the discharge circuit includes a large capacitor C, a first discharge channel 1, a control module 2, a power-off detection module 3, and a second discharge channel 4. Compared with the first embodiment, the discharge circuit of the embodiment of the present invention further includes a second discharge channel 4 connected in parallel to both ends of the large capacitor C, and the other components are the same as those of the first embodiment and use the same reference numerals.

[0029] The second discharge channel 4 is always in the on state, and the charge on the large capacitor C is released through the second discharge channel 4. As an embodiment of the present invention, the second discharge channel 4 includes a second resistor R2. Since the second discharge channel 4 always releases the charge of the large capacitor C, the input resistance of the first discharge channel 4 is designed to be large, so that its discharge time constant is large and the discharge speed is slow.

[0030] In the embodiment of the present invention, the input resistance of the first discharge channel 1 when it is turned on is much smaller than the input resistance of the second discharge channel 4. When the power supply AC is working normally, the control module 2 controls the first discharge channel 1 to be disconnected, and the electric quantity of the large capacitor C is released from the second discharge channel 2, but not from the first discharge channel 1. Since the discharge speed of the second discharge channel 2 is relatively slow, not much invalid power consumption will be generated. When the power-off detection module 3 detects that the power supply AC is powered off, it sends a power-off signal to the control module 2, and the residual electric quantity on the large capacitor C supplies power to the control module 2, and the control module 2 can still continue to work. After receiving the power-off signal, the control module 2 controls the first discharge channel 1 to be turned on, and the residual electric quantity on the large capacitor C is quickly released through the first discharge channel 1, and is also released from the second discharge channel 2. When the residual electric quantity on the large capacitor C is reduced to a certain extent, the control module 2 can no longer maintain normal operation, that is, the first discharge channel 1 can no longer be kept turned on. At this time, the first discharge channel 1 is disconnected, and the second discharge channel 2 continues to discharge, so that the residual electric quantity on the large capacitor C can be released more thoroughly.

[0031] The embodiment of the present invention uses the residual electricity on the capacitor to provide the control module with the working voltage, so that after the power supply is turned off, the control module can still continue to work, and the first discharge channel with a small discharge time constant is controlled to be turned on, and the residual electricity on the capacitor can be released through the first discharge channel. When the power supply is working normally, the first discharge channel is controlled to be turned off, so that the discharge circuit has the characteristics of fast discharge speed, low invalid power consumption, and no need for additional power supply. At the same time, a second discharge channel with a large discharge time constant and always in the on state is incorporated. When the power supply is working normally, not too much invalid power consumption will be generated. After the power supply is turned off, the residual electricity on the capacitor can be released more thoroughly.

[0032] Embodiment 3

[0033] Figure 5 Schematic diagram of the discharge circuit provided by the third embodiment of the present invention. Figure 5 As shown, the discharge circuit includes a large capacitor C, a first discharge channel 1, a control module 2, a power-off detection module 3, a second discharge channel 4 and a voltage reduction module 5. Compared with the second embodiment, the discharge circuit of the embodiment of the present invention further includes a voltage reduction module 5 connected in series between the large capacitor C and the control module 2, and the other components are the same as those in the second embodiment and use the same reference numerals.

[0034] In order to provide a suitable working voltage for the control module 2, the step-down module 5 steps down the high voltage at both ends of the large capacitor C, and then supplies power to the control module 2 to provide the working voltage for the control module 2. The step-down module 5 can be a single-stage step-down or a multi-stage step-down, which is not limited here. The control module 2 is powered by the residual electricity on the large capacitor C. When the large capacitor C is disconnected from the power supply AC or the power supply AC cannot work normally, the control module 2 can still continue to work to control the first discharge channel 1 to be turned on without the need for an additional power supply. Eliminating the additional power supply is particularly important for cost control of the circuit.

[0035] The embodiment of the present invention utilizes the residual electricity on the capacitor to provide a working voltage to the control module, so that after the power supply is turned off, the control module can still continue to work, and the first discharge channel with a small discharge time constant is controlled to be turned on, and the residual electricity on the capacitor can be released through the first discharge channel. When the power supply works normally, the first discharge channel is controlled to be turned off, thereby realizing the characteristics of the discharge circuit having fast discharge speed, low invalid power consumption, and no need for additional power supply.

[0036] Embodiment 4

[0037] The centrifuge provided in the fourth embodiment of the present invention includes the discharge circuit described in the first embodiment, the second embodiment or the third embodiment. The centrifuge has multiple functions, so that its circuit itself has a power supply, a microcontroller, a power failure detection module, etc. The circuit modules included in the discharge circuit can be reused, such as the control module 2 is the microcontroller of the centrifuge. In addition, the power supply and the power failure detection module can also be reused.

[0038] The embodiment of the present invention uses the residual electricity on the capacitor to provide the control module with an operating voltage, so that after the power is turned off, the control module can still continue to work, and the first discharge channel with a small discharge time constant is controlled to be turned on, and the residual electricity on the capacitor can be released through the first discharge channel. When the power supply works normally, the first discharge channel is controlled to be turned off, so that the discharge circuit has the characteristics of fast discharge speed, low ineffective power consumption, and no need for additional power supply. The circuit modules required for the discharge circuit reuse the circuit modules of the centrifuge itself as much as possible, which will not add too much overhead to the hardware.

[0039] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A discharge circuit, characterized in that: include: capacitance; A power supply connected to the capacitor; Power-off detection module, A first discharge channel, wherein the first discharge channel is connected in parallel to two ends of the capacitor; a second discharge channel, the second discharge channel being connected in parallel to both ends of the capacitor; as well as A control module, which is a microcontroller, connected to the capacitor and the first discharge channel respectively, and controls the on and off of the first discharge channel; Wherein, the second discharge channel includes a second resistor, which is always in a conducting state, and the charge on the capacitor is released through the second discharge channel; when the power supply is working normally, the control module controls the first discharge channel to be disconnected, and the charge on the capacitor is not released from the first discharge channel; when the power supply is powered off, the power-off detection module detects that the power supply is powered off and sends a power-off signal to the control module, the capacitor supplies power to the control module, and provides the control module with a working voltage, and the control module controls the first discharge channel to be turned on, and when the first discharge channel is turned on, the charge on the capacitor is released through the first discharge channel; the input resistance of the first discharge channel when it is turned on is less than the input resistance of the second discharge channel; The power-off detection module includes an optical coupler, a third resistor, a fourth resistor and a fifth resistor; The first end of the third resistor is connected to the power supply, and the second end of the third resistor is connected to the first end of the fourth resistor; The second end of the fourth resistor is grounded; The first end of the optical coupler is connected to the second end of the third resistor and the first end of the fourth resistor, the second end of the optical coupler is connected to the first end of the fifth resistor and the control module, and the third end of the optical coupler is grounded; The second end of the fifth resistor is connected to the power supply.

2. The discharge circuit according to claim 1, characterized in that: The first discharge channel includes a first resistor and an insulated gate bipolar transistor IGBT; A first end of the first resistor is connected to the capacitor, and a second end of the first resistor is connected to the collector of the insulated gate bipolar transistor IGBT; The emitter of the insulated gate bipolar transistor IGBT is grounded; The gate of the insulated gate bipolar transistor IGBT is connected to the control module, and the control module controls the on and off of the insulated gate bipolar transistor IGBT through the gate.

3. The discharge circuit according to claim 1, characterized in that: It also includes a step-down module, which steps down the voltage across the capacitor and then supplies power to the control module.

4. A centrifuge, characterized in that: The centrifuge comprises a discharge circuit as claimed in any one of claims 1 to 3.

5. The centrifuge according to claim 4, characterized in that The control module is a microcontroller of the centrifuge.

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