Power regulation circuit

Abstract

The power regulation circuit includes a detection unit, a control unit, and a discharge element. The detection unit includes a first end coupled to a capacitor to receive an induced current, and a second end. The control unit can generate a control current based on the induced current, and includes a first end coupled to the second end of the detection unit, a second end for generating the control current, and a third end. The discharge element can generate a discharge current based on the control current, and includes a first end coupled to the third end of the control unit, and a second end coupled to the capacitor and the first end of the detection unit to generate the discharge current. When the measured voltage at the first end of the detection unit increases, the induced current and the control current increase, and the discharge current decreases.

Description

Technical Field

[0001] The present invention relates to a power regulating circuit, and more particularly to a power regulating circuit which can reduce a discharge current when a measured voltage increases, thereby stabilizing the discharge power. Background Art

[0002] Capacitors often need to be discharged in power systems to meet regulatory requirements. Discharge power must be adjusted in response to various external factors to ensure adequate safety.

[0003] In order to prevent the discharge power from being too large, the following method can be adopted: multiple discharge elements can be used, and some or all of the discharge elements can be controlled to adjust the degree of discharge. In addition, the duty cycle of the discharge element can be adjusted to adjust the ratio of the time when the discharge element is discharging and not discharging, so that the maximum discharge power does not exceed the limit of safety conditions. In the above operation, a constant current discharge element is often used. When the measured voltage measured on the capacitor rises, the discharge power also rises. Therefore, when the measured voltage rises, the discharge power is likely to exceed the maximum allowable value, causing danger. The constant current discharge element must reserve a margin when the voltage at the discharge point is close to the maximum value to prevent the discharge power from exceeding the maximum allowable value, which also results in poor discharge efficiency. Summary of the Invention

[0004] An embodiment provides a power regulation circuit comprising a detection unit, a control unit, and a discharge element. The detection unit comprises a first end coupled to a capacitor to receive an induced current, and a second end. The control unit is configured to generate a control current based on the induced current, and comprises a first end coupled to the second end of the detection unit, a second end configured to generate the control current, and a third end. The discharge element is configured to generate a discharge current based on the control current, and comprises a first end coupled to the third end of the control unit, and a second end coupled to the capacitor and the first end of the detection unit to generate the discharge current. The capacitor is discharged by the discharge current, and when a measured voltage at the first end of the detection unit increases, the induced current and the control current increase, and the discharge current decreases. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Figures 1 to 3 Schematic diagram of a power regulation circuit in different embodiments.

[0006] Figure 4 for Figure 3 The relationship diagram between the discharge power and the measured voltage. DETAILED DESCRIPTION

[0007] Figure 1FIG. 1 is a schematic diagram of a power regulation circuit 100 in an embodiment. The power regulation circuit 100 may include a detection unit 110 , a control unit 120 , and a discharge element 130 .

[0008] The detection unit 110 includes a first terminal N11 and a second terminal N12. The first terminal N11 is coupled to the capacitor C to receive the induced current I SEN The control unit 120 is used to control the induced current I SEN Generate control current I CTL The control unit 120 includes a first terminal N21, a second terminal N22, and a third terminal N23. The first terminal N21 is coupled to the second terminal N12 of the detection unit 110, and the second terminal N22 is used to generate a control current I CTL The discharge element 130 is used to control the current I CTL Generates discharge current I DISC The discharge element 130 includes a first terminal N31 and a second terminal N32. The first terminal N31 is coupled to the third terminal N23 of the control unit 120, and the second terminal N32 is coupled to the capacitor C and the first terminal N11 of the detection unit 110 to generate a discharge current I DISC The capacitor C can be discharged by the current I DISC and discharges, and when the measured voltage V DISC Increase, the induced current I SEN And control current I CTL Can rise, and the discharge current I DISC Can be lowered.

[0009] Since the discharge power of capacitor C (hereinafter referred to as P) can be expressed as the discharge current I DISC And the measured voltage V DISC The product of (that is, P = V DISC ×I DISC ), when the measured voltage V DISC Increases, making the discharge current I DISC The discharge power P is decreased, which stabilizes the discharge power P. Therefore, adaptive control can be achieved to realize a discharge operation with a constant discharge power, thereby avoiding the danger caused by excessive discharge power and also avoiding poor discharge efficiency caused by reserving too much margin.

[0010] Figure 2 FIG. 1 is a schematic diagram of a power regulation circuit 100 in another embodiment. Figure 2As shown, the discharge element 130 may include a transistor T1. The transistor T1 may include a first terminal, a second terminal, and a control terminal. The first terminal may be coupled to the second terminal N32 of the discharge element 130. The control terminal may be coupled to the first terminal N31 of the discharge element 130. The second terminal may be coupled to a reference voltage terminal VSS. The reference voltage terminal VSS may be, for example, a ground terminal or a low voltage terminal.

[0011] like Figure 2 As shown, the control unit 120 may include a transistor T2 and a resistor R CTL The transistor T2 may include a first terminal, a second terminal, and a control terminal, wherein the control terminal may be coupled to the first terminal N21 of the control unit 120, and the second terminal may be coupled to the reference voltage terminal VSS. CTL The transistor T2 may include a first terminal and a second terminal, wherein the first terminal may be coupled to a reference voltage terminal VDD, and the second terminal may be coupled to the first terminal of the transistor T2. The reference voltage terminal VDD may be, for example, a power voltage terminal or a high voltage terminal.

[0012] According to an embodiment, the control unit 120 may include a switch SW1 and a switch SW2. Switch SW1 may be coupled between the first terminal of the transistor T2 and the third terminal N23 of the control unit 120. Switch SW2 may be coupled between the third terminal N23 of the control unit 120 and the reference voltage terminal VSS. When one of the switches SW1 and SW2 is turned on, the other of the switches SW1 and SW2 is turned off. When switch SW1 is turned on and switch SW2 is turned off, the operation of the embodiment may be performed to adjust and stabilize the discharge power of capacitor C. When switch SW1 is turned off and switch SW2 is turned on, capacitor C may not discharge. Switches SW1 and SW2 may be selectively configured as needed.

[0013] like Figure 2 As shown, the detection unit 110 may include a resistor R SEN and transistor T3. Resistor R SEN The transistor T3 includes a first terminal and a second terminal, wherein the first terminal can be coupled to the first terminal N11 of the detection unit 110. The transistor T3 includes a first terminal, a control terminal and a second terminal, wherein the first terminal can be coupled to the resistor R SEN The control end may be coupled to the first end of the transistor T3 and the second end N12 of the detection unit 110, and the second end may be coupled to the reference voltage end VSS.

[0014] Figure 2 In the test, the voltage V DISC and the threshold voltage V of transistor T3 TH The difference, divided by the resistance R SEN The resistance value, the quotient can be the induced current I SEN , as shown below: SEN =(V DISC –VTH ) / R SEN . Figure 2 In the figure, transistors T3 and T2 can form a current mirror, so the induced current I SEN Proportional to the control current I CTL , so the above equation can be expressed as I SEN =(V DISC –V TH ) / R SEN ∝I CTL ; In other words, when the induced voltage V DISC Rising, induced current I SEN And control current I CTL Since the voltage V CTL It can be obtained by subtracting the resistance R from the voltage value of the reference voltage terminal VDD. CTL The voltage across both ends can be expressed as V CTL =VDD–(I CTL ×R CTL ), so when the induced voltage V DISC Increase and control current I CTL As it rises, the voltage V CTL Can be lowered.

[0015] When the switch SW1 is turned on to discharge the power smoothly, the voltage V CTL And discharge current I DISC The relationship can be expressed as I DISC =1 / 2×μ0×C ox ×(V CTL –V TH ) 2 , where μ0 is the mobility of electrons, C ox is the capacitance of the oxide layer of transistor T1, V TH is the threshold voltage of transistor T1. Therefore, when the voltage V CTL decreases, the discharge current I DISC It can then decline.

[0016] According to the above, when the induced voltage V DISC Rising, voltage V CTL Can drop, and the discharge current I DISC It can decrease accordingly, so the discharge power can be adjusted and stabilized, where the discharge power is the induced voltage V DISC And discharge current I DISC The product of .

[0017] Figure 2 In the embodiment, transistors T1, T2 and T3 may be N-type metal oxide semiconductor transistors. Figure 2 The transistors may also be bipolar transistors.

[0018] Figure 3 FIG. 1 is a schematic diagram of a power regulation circuit 100 in another embodiment. Figure 3 In the embodiment, the control unit 120 and the discharge element 130 are similar to Figure 2 , so I will not repeat it. Figure 3 As shown, the detection unit 110 may include a resistor R SEN , transistor T31 and transistor T32. Resistor R SEN The transistor T31 may include a first terminal and a second terminal, wherein the first terminal may be coupled to the first terminal N11 of the detection unit 110. The transistor T31 may include a first terminal, a control terminal, and a second terminal, wherein the first terminal may be coupled to the resistor R SEN The second end of the control terminal can receive a predetermined voltage V CTH The transistor T32 may include a first terminal, a control terminal, and a second terminal. The first terminal may be coupled to the second terminal of the transistor T31. The control terminal may be coupled to the first terminal of the transistor T32 and the second terminal N12 of the detection unit 110. The second terminal may be coupled to the reference voltage terminal VSS.

[0019] Figure 3 In the test, the voltage V DISC Subtract the predetermined voltage V CTH , minus the threshold voltage V of transistor T32 TH The difference is divided by the resistance R SEN The resistance value, the quotient can be the induced current I SEN , which can be expressed as: I SEN =[V DISC –(V CTH +V TH )] / R SEN ∝I CTL . Similar to Figure 2 , when the measured voltage V DISC Rising, induced current I SEN And control current I CTL It can then rise, making the voltage V CTL decreases, causing the discharge current I DISC , thereby stabilizing the discharge power of capacitor C.

[0020] Figure 3 In the case of a predetermined voltage V CTH It can be the threshold voltage for starting adaptive control. DISC Less than the predetermined voltage V CTH and threshold voltage V TH The sum (that is, when V DISC <V CTH +V TH ), the induced current I SEN Can be close to zero, so that the control current ICTL Also close to zero, in this case due to the resistance R CTL There is almost no voltage drop across the two ends, so the voltage V CTL The voltage of the control terminal of the transistor T1 is approximately equal to the voltage of the reference voltage terminal VDD, which can make the voltage of the control terminal of the transistor T1 approximately a fixed voltage. In this case, the discharge performed by the discharge element 130 is a traditional constant current discharge operation, so the discharge power will vary with the measured voltage V DISC The constant power discharge operation cannot be performed. DISC Greater than or equal to the predetermined voltage V CTH and threshold voltage V TH The sum of (that is, when V DISC ≥V CTH +V TH ), the power regulation circuit 100 can perform a constant power discharge operation.

[0021] Figure 3 In the embodiment, transistors T1, T2 and T32 may be N-type metal oxide semiconductor transistors, and transistor T31 may be a P-type metal oxide semiconductor transistor. Figure 3 The transistors may also be bipolar transistors.

[0022] Figure 4 for Figure 3 The discharge power and measured voltage V DISC relationship diagram. Figure 4 In the figure, the horizontal axis can be the measured voltage V DISC , the vertical axis may be the discharge power, line A may correspond to the constant current discharge operation without using the power regulating circuit 100, and line B may correspond to the constant power discharge operation using the power regulating circuit 100. As shown by line A, according to the constant current discharge operation, the discharge power will change with the measured voltage V DISC As shown by line B, the measured voltage V DISC When the voltage is greater than a predetermined value (eg, 15 volts), the discharge power can be approximately constant, thereby achieving a constant power discharge operation. Figure 4 The voltage and power values ​​shown are only examples, and the embodiments are not limited thereto. Figure 2 The discharge power of the circuit and the measured voltage V DISC The relationship diagram is similar to Figure 4 , so I won’t go into details.

[0023] In summary, the power regulation circuit 100 provided in the embodiment can be used to implement a constant-power discharge operation, thereby achieving adaptive control, thereby avoiding the dangers caused by excessive discharge power and the drawbacks of poor discharge efficiency caused by reserving too much margin. Therefore, it is helpful in solving long-standing problems in this field.

[0024] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made according to the claims of the present invention should fall within the scope of the present invention.

[0025] [Explanation of symbols]

[0026] 100 Power Regulation Circuit

[0027] 110 Detection Unit

[0028] 120 control unit

[0029] 130 discharge element

[0030] N11, N21, N31 first end

[0031] N12, N22, N32 Second terminal

[0032] N23 Third Terminal

[0033] VDD, VSS reference voltage terminals

[0034] C capacitor

[0035] I SEN Induced current

[0036] V DISC Measured voltage

[0037] I DISC Discharge current

[0038] I CTL Control current

[0039] R SEN ,R CTL resistance

[0040] SW1, SW2 switches

[0041] T1, T2, T3, T31, T32 transistors

[0042] V CTL Voltage

[0043] V CTH Predetermined voltage

[0044] A, B lines

Claims

1. A power regulation circuit comprising: A detection unit includes a first terminal coupled to a capacitor to receive an induced current, and a second terminal; a control unit for generating a control current according to the induced current, comprising a first terminal coupled to the second terminal of the detection unit, a second terminal for generating the control current, and a third terminal; and a discharge element, configured to generate a discharge current according to the control current, comprising a first terminal coupled to the third terminal of the control unit, and a second terminal coupled to the capacitor and the first terminal of the detection unit, to generate the discharge current; wherein the capacitor is discharged by the discharge current, and when a measured voltage at the first terminal of the detection unit increases, the induced current and the control current increase, and the discharge current decreases; The discharge element further comprises: a first transistor comprising a first terminal coupled to the second terminal of the discharge element, a control terminal coupled to the first terminal of the discharge element, and a second terminal coupled to a first reference voltage terminal; The control unit further comprises: a second transistor comprising a first terminal, a control terminal coupled to the first terminal of the control unit, and a second terminal coupled to the first reference voltage terminal; and A first resistor includes a first terminal coupled to a second reference voltage terminal and a second terminal coupled to the first terminal of the second transistor.

2. The power regulation circuit as claimed in claim 1 , wherein the control unit further comprises: a first switch coupled between the first terminal of the second transistor and the third terminal of the control unit; and a second switch coupled between the third terminal of the control unit and the first reference voltage terminal; When one of the first switch and the second switch is turned on, the other one of the first switch and the second switch is turned off.

3. The power regulation circuit as claimed in claim 1 , wherein the detection unit further comprises: a second resistor comprising a first end coupled to the first end of the detection unit, and a second end; and A third transistor includes a first terminal coupled to the second terminal of the second resistor, a control terminal coupled to the first terminal of the third transistor and the second terminal of the detection unit, and a second terminal coupled to the first reference voltage terminal. 4 . The power regulating circuit as claimed in claim 3 , wherein a quotient obtained by dividing a difference between the measured voltage and a threshold voltage of the third transistor by a resistance value of the second resistor is the induced current.

5. The power regulating circuit as claimed in claim 1 , wherein the detection unit further comprises: a second resistor comprising a first end coupled to the first end of the detection unit, and a second end; a third transistor comprising a first terminal coupled to the second terminal of the second resistor, a control terminal for receiving a predetermined voltage, and a second terminal; and A fourth transistor includes a first end coupled to the second end of the third transistor, a control end coupled to the first end of the fourth transistor and the second end of the detection unit, and a second end coupled to the first reference voltage end.

6. The power regulating circuit as claimed in claim 5, wherein the induced current is obtained by dividing a difference between the measured voltage and the predetermined voltage and a threshold voltage of the fourth transistor by the resistance of the second resistor. 7 . The power regulating circuit as claimed in claim 1 , wherein the induced current is proportional to the control current.

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