Single live wire off-state power-taking circuit for preventing light flashing and single live wire switch circuit for preventing light flashing

Abstract

Single live wire off-state power-taking circuit and single live wire switch circuit for preventing light flash. The single live wire off-state power-taking circuit for preventing light flash includes a storage capacitor, a current control unit, an overvoltage conduction unit and a switching power supply unit; the storage capacitor is used to filter and store the input voltage of the single live wire; the current control unit is connected to the front end of the storage capacitor; the overvoltage conduction unit is connected to the rear end of the storage capacitor; the switching power supply unit is connected to the output end of the overvoltage conduction unit; the first threshold voltage is less than or equal to the second threshold voltage. The single live wire off-state power-taking circuit for preventing light flash can prevent the corresponding light from flickering at the moment of power-on.

Description

Technical Field

[0001] The invention relates to the field of electricity, and in particular to a single-live-wire off-state power-taking circuit and a single-live-wire switch circuit for preventing lamp flashing. Background Art

[0002] Most of the single live wire off-state power-drawing circuits on the market use capacitors in conjunction with switching power supplies to draw power. Since the switching power supply is connected in series with the live wire, the charging current of the capacitor tends to become relatively large suddenly at the moment of power supply, causing the current of the lamps (such as LED lamps or incandescent lamps, etc.) connected to the capacitor and the back end of the switching power supply to be too large, that is, causing the current flowing through the lamps in the circuit to be relatively large, which will cause the lamps to flicker.

[0003] This kind of flickering problem of lamps can easily cause a poor user experience. For example, the lamp will flicker at the moment the circuit is powered on, causing the user to wonder if the lamp is damaged, and then turn on the light to confirm, causing some unnecessary trouble and trouble. In addition, if there is a sudden call at night when there is a power outage, the lamp will also flicker, and if the user is just about to fall asleep at this time, it will also be affected, thus affecting the user's sleep.

[0004] Therefore, a new circuit is needed to solve the problem of power-on flickering in the lamp circuit. Summary of the invention

[0005] The problem solved by the present invention is to provide a single-live-wire off-state power-taking circuit and a single-live-wire switch circuit for preventing lamp flashing, so as to prevent the problem of lamp flashing at the moment of power-on.

[0006] To solve the above problems, the present invention provides a single-live-wire off-state power-taking circuit for preventing light flash, comprising: a storage capacitor, the storage capacitor is used to filter and store the input voltage of the single live wire; a current control unit, the current control unit is connected to the front end of the storage capacitor; if the positive terminal voltage of the storage capacitor is less than a first threshold voltage, the current control unit has a first total resistance value; if the positive terminal voltage of the storage capacitor is greater than or equal to the first threshold voltage, the current control unit has a second total resistance value; the first total resistance value is greater than the second total resistance value; an overvoltage conduction unit, the overvoltage conduction unit is connected to the rear end of the storage capacitor; if the positive terminal voltage of the storage capacitor is less than the second threshold voltage, the overvoltage conduction unit is a non-conducting structure; if the positive terminal voltage of the storage capacitor is greater than or equal to the second threshold voltage, the overvoltage conduction unit is a conducting structure; a switching power supply unit, the switching power supply unit is connected to the output end of the overvoltage conduction unit; the first threshold voltage is less than or equal to the second threshold voltage.

[0007] Optionally, the current control unit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a first control device and a second control device; the first end of the first resistor is connected to the input voltage end of the single live wire, the second end of the first resistor is connected to the first end of the second resistor, the second end of the second resistor is connected to the positive end of the storage capacitor, and the negative end of the storage capacitor is connected to the reference ground; the first end of the third resistor is connected between the first resistor and the second resistor, and the second end of the third resistor is connected to the first end of the fourth resistor; the input end of the first control device is connected between the first resistor and the second resistor, the output end of the first control device is connected to the second end of the second resistor, and the control end of the first control device is connected between the third resistor and the fourth resistor; the first end of the fifth resistor is connected to the second end of the second resistor, the second end of the fifth resistor is connected to the first end of the sixth resistor, and the second end of the sixth resistor is connected to the reference ground; the input end of the second control device is connected to the second end of the fourth resistor, the output end of the second control device is connected to the reference ground, and the control end of the second control device is connected between the fifth resistor and the sixth resistor.

[0008] Optionally, the first control device is a first enhancement type PMOS tube, the source of the first enhancement type PMOS tube serves as the input end, the drain of the first enhancement type PMOS tube serves as the output end, and the gate of the first enhancement type PMOS tube serves as the control end; the second control device is a first enhancement type NMOS tube, the drain of the first enhancement type NMOS tube serves as the input end, the source of the first enhancement type NMOS tube serves as the output end, and the gate of the first enhancement type NMOS tube serves as the control end.

[0009] Optionally, the overvoltage conduction unit includes a voltage-controlled conductor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, a third control device and a fourth control device; the input end of the voltage-controlled conductor is connected to the positive end of the storage capacitor, and the output end of the voltage-controlled conductor serves as the output end of the overvoltage conduction unit; the first end of the seventh resistor is connected to the input end of the voltage-controlled conductor, and the second end of the seventh resistor is connected to the first end of the eighth resistor; the input end of the third control device is connected to the input end of the voltage-controlled conductor, the output end of the third control device is connected to the output end of the voltage-controlled conductor, and the control end of the third control device is connected between the seventh resistor and the eighth resistor; the first end of the ninth resistor is connected to the output end of the voltage-controlled conductor, the second end of the ninth resistor is connected to the first end of the tenth resistor, and the second end of the tenth resistor is connected to the reference ground; the input end of the fourth control device is connected to the second end of the eighth resistor, the output end of the fourth control device is connected to the reference ground, and the control end of the fourth control device is connected between the ninth resistor and the tenth resistor.

[0010] Optionally, the voltage-controlled conductor is a high-voltage trigger diode or a bidirectional trigger diode.

[0011] Optionally, the third control device is a second enhancement type PMOS tube, the source of the second enhancement type PMOS tube serves as the input end, the drain of the second enhancement type PMOS tube serves as the output end, and the gate of the second enhancement type PMOS tube serves as the control end; the fourth control device is a second enhancement type NMOS tube, the drain of the second enhancement type NMOS tube serves as the input end, the source of the second enhancement type NMOS tube serves as the output end, and the gate of the second enhancement type NMOS tube serves as the control end.

[0012] Optionally, the first threshold voltage is 60V-250V, and the second threshold voltage is 60V-250V.

[0013] Optionally, the capacitance value of the storage capacitor is 0.1 μF to 10 μF.

[0014] Optionally, the resistance of the first resistor is 1 kΩ-200 kΩ, and the total resistance of the first resistor and the second resistor is 100 kΩ-1 MΩ.

[0015] Optionally, the single-live-wire off-state power-taking circuit for preventing lamp flashing further includes a switching power supply unit, and the switching power supply unit is connected to the output end of the overvoltage conduction unit.

[0016] Optionally, the single-live-wire off-state power-taking circuit for preventing light flashing also includes a second current control unit, which is connected to the front end of the storage capacitor; if the positive terminal voltage of the storage capacitor is less than a third threshold voltage, the second current control unit has a third total resistance value; if the positive terminal voltage of the storage capacitor is greater than or equal to the third threshold voltage, the second current control unit has a fourth total resistance value; the third total resistance value is greater than the fourth total resistance value; the third threshold voltage is less than or equal to the second threshold voltage.

[0017] To solve the above problems, the present invention also provides a single-live wire switching circuit for preventing light flash, comprising: the single-live wire off-state power supply circuit as described above; a rectifier circuit, the rectifier circuit being connected to the front end of the single-live wire off-state power supply circuit for preventing light flash; an on-state power supply circuit, the on-state power supply circuit being connected to the single-live wire off-state power supply circuit for preventing light flash; and a control system, the control system being connected to the on-state power supply circuit and the single-live wire off-state power supply circuit for preventing light flash.

[0018] In the present invention, the single-live-wire off-state power-taking circuit is provided with a current control unit whose resistance value can change accordingly, which can prevent the lamp connected to the circuit from flashing due to excessive current at the moment of power-on. At the same time, the single-live-wire off-state power-taking circuit has a corresponding overvoltage conduction unit for ensuring the stability of power supply, which can ensure that in the corresponding switch circuit, when the power is taken in the off state, the power supply is first supplied from the storage capacitor to the switch power supply unit, and then the switch power supply unit provides sufficient power to the corresponding control system (i.e., provides sufficient power), ensuring that the corresponding switch circuit can work stably during the off-state power taking process. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a principle block diagram of a single live wire off-state power-taking circuit for preventing light flashing provided by an embodiment of the present invention;

[0020] Figure 2 yes Figure 1 Circuit diagram corresponding to the storage capacitor, current control unit and overvoltage conduction unit;

[0021] Figure 3 yes Figure 1 The circuit diagram corresponding to the switching power supply unit;

[0022] Figure 4 It is a principle block diagram of a single live wire switch circuit for preventing light flashing provided by another embodiment of the present invention;

[0023] Figure 5 yes Figure 4 Circuit diagram of the rectifier circuit in Figure 2;

[0024] Figure 6 yes Figure 4Circuit diagram of the open state power taking circuit;

[0025] Figure 7 yes Figure 4 Circuit diagram of the control system. DETAILED DESCRIPTION

[0026] As described in the background technology, lamps will flicker at the moment of power-on because the lighting current of the lamps is usually low, and they can be lit with a relatively small current. Since the single-live-wire circuit requires that the corresponding switch circuit can draw power in both the off and on states, the circuit will inevitably introduce the corresponding current when drawing power in the off state, and this current will usually suddenly reach a large value at the moment of power-on, causing the lamps to flicker. It can be seen that how to reduce the current of the off-state power-drawing circuit at the moment of power-on and ensure that the off-state power-drawing circuit works smoothly in the off-state power-drawing state has become a common problem faced by the industry.

[0027] The present invention provides a new single-live-wire off-state power-taking circuit and a corresponding switch circuit for preventing lamp flashing, so as to solve the above-mentioned problem.

[0028] For a clearer representation, the present invention is described in detail below with reference to the accompanying drawings.

[0029] The embodiment of the present invention provides a single live wire off-state power supply circuit for preventing light flashing. Figure 1 , including a storage capacitor 10, a current control unit 20, an overvoltage conduction unit 30 and a switching power supply unit 40.

[0030] Among them, the storage capacitor 10 is used to filter and store the input voltage of the single live wire. The current control unit 20 is connected to the front end of the storage capacitor 10. If the positive terminal voltage of the storage capacitor 10 is less than the first threshold voltage, the current control unit 20 has a first total resistance value. If the positive terminal voltage of the storage capacitor 10 is greater than or equal to the first threshold voltage, the current control unit 20 has a second total resistance value. The first total resistance value is greater than the second total resistance value. The overvoltage conduction unit 30 is connected to the rear end of the storage capacitor 10. If the positive terminal voltage of the storage capacitor 10 is less than the second threshold voltage, the overvoltage conduction unit 30 is a non-conducting structure. If the positive terminal voltage of the storage capacitor 10 is greater than or equal to the second threshold voltage, the overvoltage conduction unit 30 is a conducting structure. The switching power supply unit 40 is connected to the output end of the overvoltage conduction unit 30. The first threshold voltage is less than or equal to the second threshold voltage.

[0031] In the single-live-wire off-state power-taking circuit for preventing light flashing provided in this embodiment, the storage capacitor 10 is used to filter and store the input voltage of the single live wire, that is, mainly to filter and store the power supply from the corresponding single live wire (the corresponding power supply can be rectified first).

[0032] The current control unit 20 is mainly used to control the charging current of the storage capacitor, and the current control unit 20 can change the total resistance value (i.e., impedance change) as the voltage of the storage capacitor 10 increases. Specifically, the current control unit 20 can reduce the total resistance value when the voltage value of the positive terminal of the storage capacitor 10 increases to a certain value (first threshold voltage), and because the current control unit 20 is located at the front end of the storage capacitor 10 in the entire off-state power-taking circuit, once the total resistance value of the current control unit 20 decreases, the current in the circuit can be increased, thereby speeding up the charging speed of the storage capacitor 10.

[0033] The above situation can be understood in reverse as follows: on the one hand, at the beginning, the current control unit 20 has a larger total resistance value (first total resistance value). Therefore, when the single-live-wire-off-state power-taking circuit starts to draw power, due to the effect of the larger total resistance value, the current in the circuit is smaller, thereby preventing the flickering of lamps (such as LED lamps, incandescent lamps, fluorescent lamps, energy-saving lamps and halogen lamps, etc., most of the lamps on the market) caused by excessive current at the moment when the single-live-wire-off-state power-taking circuit is powered on, that is, the function of preventing light flashes is realized; on the other hand, in order to ensure that the subsequent power-taking action is carried out more quickly after preventing light flashes (otherwise the power taking will be affected), the current control unit 20 of this embodiment can change the larger total resistance value into a smaller total resistance value (second total resistance value) in time. At this time, the current will increase accordingly (but this increase will obviously not be as large as the current at the moment of power-on in the prior art), thereby improving the charging speed of the storage capacitor 10.

[0034] In the above process, the current control unit 20 is equivalent to being able to collect the voltage value of the storage capacitor 10, so, Figure 1 Two different arrows are used to indicate the connection relationship between the two. In addition, the characteristic of the current control unit 20 is that when the current control unit 20 detects that the storage capacitor 10 is higher than the first voltage threshold, the DC impedance of the current control unit 20 itself is reduced (which is equivalent to the DC impedance of the entire off-state power supply circuit being reduced).

[0035] From the above content, it can be known that the cooperation between the current control unit 20 and the storage capacitor 10 enables the single live wire off-state power-taking circuit to prevent the occurrence of light flashing, so the circuit becomes a single live wire off-state power-taking circuit that prevents light flashing.

[0036] However, in the switch circuit, if there are only these two partial circuits, the corresponding off-state power supply circuit will be unstable.

[0037] This is because, when the single-live-wire off-state power-taking circuit is working, the switching power supply unit 40 needs to take power from the storage capacitor 10. Once the switching power supply unit 40 takes power from the storage capacitor 10, the voltage (positive terminal voltage) of the storage capacitor 10 may increase relatively slowly, making it difficult to reach the above-mentioned first threshold voltage, and further making it difficult to achieve the total resistance change function of the current control unit 20; or, it is also easy to cause when the voltage of the storage capacitor 10 has just reached the first threshold voltage (at this time, the total resistance of the current control unit 20 has just changed from the larger first total resistance value to the smaller second total resistance value), due to the switching power supply unit 40 taking power from the storage capacitor 10, the voltage of the storage capacitor 10 drops back to less than the first threshold voltage, and at this time the total resistance of the current control unit 20 suddenly changes from the smaller second total resistance value to the larger first total resistance value, which will cause circuit instability.

[0038] Therefore, in this embodiment, an overvoltage conduction unit 30 is disposed at the rear end of the storage capacitor 10 to ensure the stability of the circuit.

[0039] Specifically, it can be seen from the above structural content that the overvoltage conduction unit 30 can achieve the following functions: when the voltage difference between the positive end of the storage capacitor 10 and the input end of the switching power supply unit 40 is greater than or equal to the second voltage threshold, the overvoltage conduction unit 30 is turned on (that is, it is a conduction structure at this time), and the switching power supply unit 40 can draw power from the storage capacitor 10, that is, when the overvoltage conduction unit 30 is turned on, the switching power supply unit 40 can work normally to provide power for the control system of the corresponding switching circuit (it should be noted that the single-live-wire off-state power-drawing circuit is usually a part of the switching circuit); and when the voltage difference between the positive end of the storage capacitor 10 and the input end of the switching power supply unit 40 is less than the second voltage threshold, the overvoltage conduction unit 30 is disconnected (that is, it is a non-conducting structure at this time), and the switching power supply unit 40 is disconnected from the storage capacitor 10 and does not draw power (at this time, the control system of the switching circuit is usually powered by the on-state power-drawing circuit of the switching circuit).

[0040] From the above content, it can be known that only when the voltage of the storage capacitor 10 is higher than the second voltage threshold, the storage capacitor 10 provides power to the switching power supply unit 40, which ensures the stability of the corresponding circuit. It can be understood and compared to: the storage capacitor 10 is equivalent to a pool, and its voltage is equivalent to the water level of the pool; the switching power supply unit 40 is equivalent to a water-using device; this embodiment controls the water level controller of the overvoltage conduction unit 30 so that only when the corresponding water level of the storage capacitor 10 pool is higher than a certain value, the storage capacitor 10 pool starts to supply water (power) to the switching power supply unit 40, a water-using device, thereby ensuring the stability of the water supply (power supply) process.

[0041] As mentioned above, the single-live-wire off-state power-taking circuit is usually a part of the switch circuit. As can be seen from the above content, the present embodiment can provide a single-live-wire off-state power-taking circuit. In this single-live-wire off-state power-taking circuit, since a current control unit 20 whose resistance value can change accordingly is provided, it can prevent the lamp connected to this circuit from flashing due to excessive current at the moment of power-on. At the same time, the single-live-wire off-state power-taking circuit has a corresponding overvoltage conduction unit 30 for ensuring the stability of power supply, which can ensure that in the corresponding switch circuit, when the power is taken in the off state, the power supply is first supplied by the storage capacitor 10 to the switch power supply unit 40, and then the switch power supply unit 40 provides sufficient power to the corresponding control system (i.e., provides sufficient power), ensuring that the corresponding switch circuit can work stably during the off-state power-taking process.

[0042] Please refer to Figure 2 In this embodiment, the current control unit 20 includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a first control device Q1 and a second control device Q2.

[0043] Please refer to Figure 2 In this embodiment, the first end of the first resistor R1 is connected to the input voltage end of the single live wire, the second end of the first resistor R1 is connected to the first end of the second resistor R2, the second end of the second resistor R2 is connected to the positive end of the storage capacitor 10, and the negative end of the storage capacitor 10 is connected to the reference ground.

[0044] Please refer to Figure 2 In this embodiment, a first end of the third resistor R3 is connected between the first resistor R1 and the second resistor R2, and a second end of the third resistor R3 is connected to a first end of the fourth resistor R4.

[0045] Please refer to Figure 2 In this embodiment, the input end of the first control device Q1 is connected between the first resistor R1 and the second resistor R2, the output end of the first control device Q1 is connected to the second end of the second resistor R2, and the control end of the first control device Q1 is connected between the third resistor R3 and the fourth resistor R4.

[0046] Please refer to Figure 2 In this embodiment, the first end of the fifth resistor R5 is connected to the second end of the second resistor R2, the second end of the fifth resistor R5 is connected to the first end of the sixth resistor R6, and the second end of the sixth resistor R6 is connected to the reference ground.

[0047] Please refer to Figure 2 In this embodiment, the input end of the second control device Q2 is connected to the second end of the fourth resistor R4, the output end of the second control device Q2 is connected to the reference ground, and the control end of the second control device Q2 is connected between the fifth resistor R5 and the sixth resistor R6.

[0048] Please refer to Figure 2 In this embodiment, the first control device Q1 is a first enhancement mode PMOS tube, the source of the first enhancement mode PMOS tube serves as an input terminal, the drain of the first enhancement mode PMOS tube serves as an output terminal, and the gate of the first enhancement mode PMOS tube serves as a control terminal.

[0049] Please refer to Figure 2 In this embodiment, the second control device Q2 is a first enhancement type NMOS tube, the drain of the first enhancement type NMOS tube serves as an input terminal, the source of the first enhancement type NMOS tube serves as an output terminal, and the gate of the first enhancement type NMOS tube serves as a control terminal.

[0050] The third resistor R3, the fourth resistor R4, the fifth resistor R5 and the sixth resistor R6 generally form a corresponding voltage-dividing resistor structure, and their resistance values ​​can be set to be relatively large, such as reaching the megohm level, so as to reduce the current of the entire circuit and the power consumption.

[0051] Please refer to Figure 2 In this embodiment, the storage capacitor 10 is implemented by capacitor CE1, and in this embodiment, the capacitance value of the storage capacitor 10 can be 0.1μF to 10μF, and the specific value can be adjusted according to the applicability of each specific circuit.

[0052] In this embodiment, the overvoltage conduction unit 30 includes a voltage control conduction device D19, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, a third control device Q3 and a fourth control device Q4. The input end of the voltage control conduction device D19 is connected to the positive end of the storage capacitor 10, and the output end of the voltage control conduction device D19 serves as the output end of the overvoltage conduction unit 30 (such as Figure 2 OUT terminal in the figure). The first terminal of the seventh resistor R7 is connected to the input terminal of the voltage-controlled conductor D19, and the second terminal of the seventh resistor R7 is connected to the first terminal of the eighth resistor R8. The input terminal of the third control device Q3 is connected to the input terminal of the voltage-controlled conductor D19, the output terminal of the third control device Q3 is connected to the output terminal of the voltage-controlled conductor D19, and the control terminal of the third control device Q3 is connected between the seventh resistor R7 and the eighth resistor R8. The first terminal of the ninth resistor R9 is connected to the output terminal of the voltage-controlled conductor D19, the second terminal of the ninth resistor R9 is connected to the first terminal of the tenth resistor R10, and the second terminal of the tenth resistor R10 is connected to the reference ground. The input terminal of the fourth control device Q4 is connected to the second terminal of the eighth resistor R8, the output terminal of the fourth control device Q4 is connected to the reference ground, and the control terminal of the fourth control device Q4 is connected between the ninth resistor R9 and the tenth resistor R10.

[0053] It should be noted that the voltage-controlled conductor D19 of this embodiment is a voltage-controlled structural device, and its own device requirement is that it is conductive only when the voltage across it reaches a certain value, otherwise it is non-conductive.

[0054] In this embodiment, it can be seen from the connection structure of the voltage-controlled conductor D19 that the function of the voltage-controlled conductor D19 is to detect whether the positive terminal voltage of the storage capacitor 10 reaches the above-mentioned second threshold voltage. Once it is detected that the positive terminal voltage of the storage capacitor 10 reaches the second threshold voltage, the voltage-controlled conductor D19 is turned on, otherwise, the voltage-controlled conductor D19 is not turned on.

[0055] In this embodiment, the voltage-controlled conductor D19 can be a high-voltage trigger diode (SIDAC). The high-voltage trigger diode is usually a non-polar bidirectional trigger device. The trigger voltage of the high-voltage trigger diode is high and the range is wide. Its trigger voltage can be 75V-380V, which is suitable for this embodiment. In other embodiments, the voltage-controlled conductor D19 can also be a bidirectional trigger diode (DIAC). The trigger voltage range of the bidirectional trigger diode can be 60V-70V, which is suitable for the case where the trigger voltage is low.

[0056] In this embodiment, the third control device Q3 is a second enhancement mode PMOS transistor, the source of the second enhancement mode PMOS transistor is used as the input terminal, the drain of the second enhancement mode PMOS transistor is used as the output terminal, and the gate of the second enhancement mode PMOS transistor is used as the control terminal.

[0057] The fourth control device Q4 is a second enhancement mode NMOS transistor, the drain of the second enhancement mode NMOS transistor is used as an input terminal, the source of the second enhancement mode NMOS transistor is used as an output terminal, and the gate of the second enhancement mode NMOS transistor is used as a control terminal.

[0058] Similar to the above, the seventh resistor R7, the eighth resistor R8, the ninth resistor R9 and the tenth resistor R10 generally constitute a corresponding voltage-dividing resistor structure, and their resistance values ​​can be set to be relatively large, such as reaching the megohm level, so as to make the entire circuit current smaller and the power consumption smaller.

[0059] Above Figure 2 The specific circuit of the current control unit 20 and the specific circuit of the overvoltage conduction unit 30 shown in the figure implement the corresponding functions as follows:

[0060] When the entire circuit (circuit) is not powered, the voltage across the storage capacitor 10 is 0V (that is, the positive terminal voltage is 0V because its negative terminal is connected to the reference ground); when the circuit (circuit) is powered (powered on), since the voltage is very small at the beginning, according to the circuit structure, the second control device Q2 as the NMOS enhancement tube is turned off, and the first control device Q1 as the PMOS enhancement tube is also turned off. At this time, the resistance value of the current control unit 20 connected to the entire circuit includes the resistance value of the first resistor R1 and the resistance value of the second resistor R2. Under the action of these two resistance values, the storage capacitor 10 will start to charge in a relatively small current, and this relatively small current can suppress the phenomenon of suddenly bringing a large charging current to the capacitor CE1 at the moment of power-on, that is, suppressing the flickering phenomenon of the corresponding lamp at the moment of power-on; in this initial stage, the positive terminal of the storage capacitor 10 (that is, Figure 2 The voltage at the VDD end in the figure starts to rise from 0V.

[0061] Before the voltage at the positive terminal of the storage capacitor 10 reaches the first voltage threshold (180V), although the voltage continues to rise, it can be seen from the circuit structure that the second control device Q2 as an NMOS enhancement tube has not yet reached the conduction condition (that is, the divided voltage of the corresponding voltage-dividing resistor has not reached the conduction voltage of the second control device Q2). At this time, the second control device Q2 is still not turned on, and the first control device Q1 is also not turned on accordingly. The circuit current still charges the capacitor CE1 (that is, the storage capacitor 10) through the first resistor R1 and the second resistor R2. At this time, since the resistance values ​​of the first resistor R1 and the second resistor R2 are both large, the charging speed of the CE1 capacitor is still slow, and at this time, the voltage at the positive terminal of the storage capacitor 10 has not reached the first threshold voltage, and certainly has not reached the second threshold voltage. Therefore, the voltage control conductor D19 has not been turned on, and the output end of the overvoltage conduction unit 30 (such as Figure 2 There is no voltage output at the OUT terminal.

[0062] When the voltage at the positive end of the storage capacitor 10 reaches the first voltage threshold (180V), the second control device Q2 reaches the conduction condition and is turned on through the voltage division structure inside the current control unit 20, and the second control device Q2 will further turn on the first control device Q1. At this time, the current of the circuit only needs to pass through the first resistor R1 to charge the capacitor CE1 (and the second resistor R2 is short-circuited by the first control device Q1). At this time, the resistance of the charging circuit is reduced (that is, the total resistance of the current control unit 20 is reduced), and the charging speed of the storage capacitor 10 is accelerated; but because under normal circumstances, the first threshold voltage is less than the second threshold voltage, therefore, at this time the overvoltage conduction unit 30 is still a non-conducting structure, such as Figure 2 There is still no voltage output at the OUT terminal;

[0063] When the voltage at the positive terminal of the storage capacitor 10 reaches a second threshold voltage (such as DC 200V), the voltage control conductor D19 of the overvoltage conduction unit 30 is turned on. Figure 2 The OUT terminal voltage also rises to 200V, the storage capacitor 10 starts to supply power to the switching power supply unit 40, and the switching power supply unit 40 starts to work; and, in this process, the fourth control device Q4 also reaches the corresponding turn-on condition and is turned on (and before that the fourth control device Q4 has been in the off state), thereby also turning on the third control device Q3 (and before that the third control device Q3 has also been in the off state); and once the third control device Q3 is turned on, it can ensure that the switching power supply unit 40 is no longer affected by the voltage control conductor D19, and can continue to obtain the corresponding power supply from the storage capacitor 10.

[0064] After the above process, since the switching power supply unit 40 usually works intermittently (to ensure that the power consumption of the circuit is smaller), the corresponding single-live-wire off-state power-drawing circuit will be under the control of the internal chip of the switching power supply unit 40, and the switching power supply unit 40 will no longer draw power from the storage capacitor 10 (that is, no energy transfer is performed). At this time, the storage capacitor 10 is storing electricity to prepare for the switching power supply unit 40 to draw power in the next cycle.

[0065] When the entire circuit is powered off, the voltage across the storage capacitor 10 returns to 0V, and each control device is cut off again. At this time, the above-mentioned entire process is repeated.

[0066] Please refer to Figure 3 In this embodiment, a specific circuit of the switching power supply unit 40 is as follows Figure 3 As shown, it includes a switching power supply control chip U1 (model may be LNK574DG-TL) and a transformer T2, as well as corresponding peripheral circuits, which are not described in detail in the present invention.

[0067] In this embodiment, the first threshold voltage may be 60V-250V, and the second threshold voltage may be 60V-250V. Moreover, as mentioned above, the second threshold voltage is greater than or equal to the first threshold voltage. In a specific case, the first threshold voltage may be 180V, and the second threshold voltage may be 200V.

[0068] In this embodiment, the resistance of the first resistor R1 is 1 kΩ-200 kΩ, and the total resistance of the first resistor R1 and the second resistor R2 is 100 kΩ-1 MΩ. Figure 2As can be seen from the circuit shown, the total resistance of the first resistor R1 and the second resistor R2 is substantially equal to the first total resistance of the current control unit 20, and the resistance of the first resistor R1 is substantially equal to the second total resistance of the current control unit 20. Therefore, by setting the total resistance of the first resistor R1 and the second resistor R2, the first total resistance of the current control unit 20 can be set, thereby achieving control of a correspondingly smaller current. Similarly, by setting the resistance of the first resistor R1, the second total resistance of the current control unit 20 can be set, thereby achieving control of a correspondingly larger current.

[0069] It should be noted that, in the present embodiment, the parameters of the above-mentioned components are set according to the fact that the mains electricity in my country is 220V AC, but they are not used to limit the maximum conception of the present invention. For example, in other countries, when the mains electricity in these countries is 100V AC (such as Japan), in the circuit design of the present invention, the corresponding component parameters can be adjusted accordingly according to this power supply change. Along this line of thought, the value ranges of the first threshold voltage and the second threshold voltage mentioned above in the present application will be different due to the difference in the mains electricity, and can be adjusted according to the implementation needs. The changes in these parameter selections and threshold design still belong to the protection scope of the present invention.

[0070] It should be noted that, in this embodiment, there is only one current control unit 20, but in other embodiments of the present invention, in addition to the current control unit 20, the single live wire off-state power-taking circuit for preventing light flashing may also include a second current control unit, and the second current control unit is connected to the front end of the storage capacitor; if the positive terminal voltage of the storage capacitor is less than the third threshold voltage, the second current control unit has a third total resistance value; if the positive terminal voltage of the storage capacitor is greater than or equal to the third threshold voltage, the second current control unit has a fourth total resistance value; the third total resistance value is greater than the fourth total resistance value; the third threshold voltage is less than or equal to the second threshold voltage. In other words, the specific circuit of this second current control unit can be the same as the current control unit 20, and it only needs to select the corresponding device parameters to set its threshold voltage to the third threshold voltage. The third threshold voltage can be higher than the aforementioned first threshold voltage, or it can be lower than the aforementioned first threshold voltage, but the third threshold voltage is less than or equal to the aforementioned second threshold voltage, and the reason is also to ensure the stability of the circuit.

[0071] In addition, in further other embodiments, there may be a third current control unit, and a corresponding fourth threshold voltage, a fifth total resistance value, and a sixth total resistance value, and there may also be a fourth current control unit, and a corresponding fifth threshold voltage, a seventh total resistance value, and an eighth total resistance value. When these first to fifth threshold voltages coexist, in some specific value cases, the fifth threshold voltage may be 50V, the fourth threshold voltage may be 100V, the third threshold voltage may be 150V, and the first threshold voltage may be 180V.

[0072] Another embodiment of the present invention further provides a single live wire switch circuit 1000 for preventing lamp flashing. Figure 4 shown.

[0073] like Figure 4 As shown, the single live wire switch circuit 1000 for preventing lamp flashing includes a single live wire off-state power supply circuit 100, a rectifier circuit 200, an on-state power supply circuit 300 and a control system 400. In addition, the single live wire switch circuit 1000 for preventing lamp flashing is used to cooperate with the lamp 2000 to prevent the lamp 2000 from flickering at the moment of power-on.

[0074] like Figure 4 As shown, the single live wire off-state power circuit 100 includes a storage capacitor 10, a current control unit 20, an overvoltage conduction unit 30 and a switch power supply unit 40. More structures, properties and advantages of the single live wire off-state power circuit 100 can refer to the corresponding contents of the aforementioned embodiments (and can be combined with reference to Figures 1 to 3 The rectifier circuit 200 is connected to the front end of the single live wire off-state power-taking circuit for preventing light flash. The on-state power-taking circuit 300 is connected to the single live wire off-state power-taking circuit for preventing light flash. The control system 400 is connected to the on-state power-taking circuit 300 and the single live wire off-state power-taking circuit 100 for preventing light flash.

[0075] The rectifier circuit 200 is mainly used to rectify the power supply voltage from the live wire input and the live wire output. The rectifier circuit 200 can be implemented by various known circuits, which can be a full-bridge rectifier circuit or a half-bridge rectifier circuit. One specific form is as follows: Figure 5 As shown, this manual does not provide a detailed description.

[0076] The open-state power circuit 300 may be a circuit including a MOC3061 series photoelectric bidirectional thyristor driver. MOC3061 is a new type of photoelectric coupling device. A corresponding specific open-state power circuit 300 is as follows: Figure 6 In other embodiments, the open-state power circuit 300 may also be a bidirectional thyristor drive without an optocoupler. In other embodiments, the open-state power circuit 300 may also be a circuit composed of a relay and a MOS tube.

[0077] The control system 400 can be implemented by a corresponding microcontroller system (microcontroller unit, also known as a single-chip microcomputer, MCU), and specifically, a chip of type STM8L001J3 can be used. The entire control system 400 may include corresponding peripheral circuits. A specific circuit is as follows: Figure 7 In other embodiments, the control system 400 may also be other single-chip microcomputers or embedded chips, or digital signal processing chips (DSP), wireless chips such as Bluetooth, Zigbee or Wifi with main control, or touch chips or field programmable gate array (FPGA) chips with main control.

[0078] It should be noted that Figure 4 In the diagram, arrows indicate connections, but lines without arrows also indicate connections.

[0079] It should be noted that the present embodiment does not provide a detailed circuit diagram of the single live wire off-state power-taking circuit 100. Therefore, the aforementioned Figure 2 and Figure 3 The detailed circuit is shown, and Figure 2 and Figure 3 The detailed circuit shown is Figures 5 to 7 For the connection relationship between the various parts, you can refer to their corresponding port symbols (including OUT port, P0 port, P1 port and P2 port, etc.).

[0080] For example, according to the display of these port symbols, Figure 3 The circuit shown is Figure 6 The connection relationship of the circuit shown in FIG. 1 can determine that the single live wire off-state power circuit 100 is connected to the on-state power circuit 300 and the control system 400 through the corresponding switching power supply unit 40 (combined with Figure 3 , Figure 6 and Figure 7 The switching power supply unit 40 is directly connected to the open state power circuit 300 to achieve indirect connection with the control system 400, and can be returned to the reference Figure 4 ).

[0081] Combination Figures 4 to 7 In the circuit provided in this embodiment, when the control system 400 receives a light-on command, it is in the on-state power-taking state. The control system 400 controls the on-state power-taking circuit 300 to work, controls the turning on of the lamp 2000 through the on-state power-taking circuit 300, and obtains power from the current on-state circuit to power the control system 400.

[0082] When the control system 400 receives a shutdown command, the control system 400 controls the on-state power supply circuit 300 to shut down, and controls the lamp to shut down through the on-state power supply circuit 300. At this time, the power supply is supplied by the switching power supply unit 40 of the single-live-wire off-state power supply circuit 100 to the control system 400, that is, the single-live-wire off-state power supply circuit 100 supplies power to the control system 400.

[0083] Since the single-live-wire switch circuit 1000 for preventing lamp flash in the present embodiment has a corresponding single-live-wire off-state power supply circuit 100, the entire single-live-wire switch circuit 1000 can achieve the same function as the aforementioned embodiment in the off-state power supply state: preventing the lamp 2000 connected to this circuit from flashing due to excessive current at the moment of power-on. At the same time, in the single-live-wire switch circuit 1000, in the off state, the power supply is first supplied from the storage capacitor 10 to the switching power supply unit 40, and then the switching power supply unit 40 provides sufficient power to the corresponding control system 400 (i.e., provides sufficient power), thereby ensuring that the single-live-wire switch circuit 1000 can operate stably in the off-state power supply process.

[0084] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A single live wire off-state power supply circuit for preventing lamp flash, characterized in that: include: A storage capacitor, the storage capacitor is used to filter and store the input voltage of the single live wire; A current control unit, the current control unit is connected to the front end of the storage capacitor; If the positive terminal voltage of the storage capacitor is less than the first threshold voltage, the current control unit has a first total resistance value; if the positive terminal voltage of the storage capacitor is greater than or equal to the first threshold voltage, the current control unit has a second total resistance value; the first total resistance value is greater than the second total resistance value; An overvoltage conduction unit, the overvoltage conduction unit is connected to the rear end of the storage capacitor; if the positive terminal voltage of the storage capacitor is less than a second threshold voltage, the overvoltage conduction unit is a non-conducting structure; if the positive terminal voltage of the storage capacitor is greater than or equal to the second threshold voltage, the overvoltage conduction unit is a conducting structure; The first threshold voltage is less than or equal to the second threshold voltage.

2. The single live wire off-state power supply circuit according to claim 1, characterized in that: The current control unit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a first control device and a second control device; The first end of the first resistor is connected to the input voltage end of the single live wire, the second end of the first resistor is connected to the first end of the second resistor, the second end of the second resistor is connected to the positive end of the storage capacitor, and the negative end of the storage capacitor is connected to the reference ground; The first end of the third resistor is connected between the first resistor and the second resistor, and the second end of the third resistor is connected to the first end of the fourth resistor; The input end of the first control device is connected between the first resistor and the second resistor, the output end of the first control device is connected to the second end of the second resistor, and the control end of the first control device is connected between the third resistor and the fourth resistor; The first end of the fifth resistor is connected to the second end of the second resistor, the second end of the fifth resistor is connected to the first end of the sixth resistor, and the second end of the sixth resistor is connected to the reference ground; The input end of the second control device is connected to the second end of the fourth resistor, the output end of the second control device is connected to the reference ground, and the control end of the second control device is connected between the fifth resistor and the sixth resistor.

3. The single live wire off-state power supply circuit according to claim 2, characterized in that: The first control device is a first enhancement-mode PMOS transistor, the source of the first enhancement-mode PMOS transistor is used as an input terminal, the drain of the first enhancement-mode PMOS transistor is used as an output terminal, and the gate of the first enhancement-mode PMOS transistor is used as a control terminal; The second control device is a first enhancement mode NMOS transistor, the drain of the first enhancement mode NMOS transistor is used as an input terminal, the source of the first enhancement mode NMOS transistor is used as an output terminal, and the gate of the first enhancement mode NMOS transistor is used as a control terminal.

4. The single live wire off-state power supply circuit according to claim 2 or 3, characterized in that: The overvoltage conduction unit includes a voltage-controlled conductor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, a third control device and a fourth control device; The input end of the voltage-controlled conductor is connected to the positive end of the storage capacitor, and the output end of the voltage-controlled conductor serves as the output end of the overvoltage conduction unit; A first end of the seventh resistor is connected to the input end of the voltage-controlled conductor, and a second end of the seventh resistor is connected to the first end of the eighth resistor; The input end of the third control device is connected to the input end of the voltage-controlled conductor, the output end of the third control device is connected to the output end of the voltage-controlled conductor, and the control end of the third control device is connected between the seventh resistor and the eighth resistor; The first end of the ninth resistor is connected to the output end of the voltage-controlled conductor, the second end of the ninth resistor is connected to the first end of the tenth resistor, and the second end of the tenth resistor is connected to the reference ground; The input end of the fourth control device is connected to the second end of the eighth resistor, the output end of the fourth control device is connected to the reference ground, and the control end of the fourth control device is connected between the ninth resistor and the tenth resistor.

5. The single live wire off-state power supply circuit according to claim 4, characterized in that: The voltage-controlled conductor is a high-voltage trigger diode or a bidirectional trigger diode.

6. The single live wire off-state power supply circuit according to claim 4, characterized in that: The third control device is a second enhancement-mode PMOS transistor, the source of the second enhancement-mode PMOS transistor is used as the input terminal, the drain of the second enhancement-mode PMOS transistor is used as the output terminal, and the gate of the second enhancement-mode PMOS transistor is used as the control terminal; The fourth control device is a second enhancement mode NMOS transistor, the drain of the second enhancement mode NMOS transistor is used as the input terminal, the source of the second enhancement mode NMOS transistor is used as the output terminal, and the gate of the second enhancement mode NMOS transistor is used as the control terminal.

7. The single live wire off-state power supply circuit according to claim 2, characterized in that: The first threshold voltage is 60V-250V, and the second threshold voltage is 60V-250V; the capacitance of the storage capacitor is 0.1μF to 10μF; the resistance of the first resistor is 1kΩ-200kΩ, and the total resistance of the first resistor and the second resistor is 100kΩ-1MΩ.

8. The single live wire off-state power supply circuit according to claim 1, characterized in that: It also includes a switching power supply unit, which is connected to the output end of the overvoltage conduction unit.

9. The single live wire off-state power supply circuit according to claim 1, characterized in that: It also includes a second current control unit, which is connected to the front end of the storage capacitor; if the positive terminal voltage of the storage capacitor is less than a third threshold voltage, the second current control unit has a third total resistance value; if the positive terminal voltage of the storage capacitor is greater than or equal to the third threshold voltage, the second current control unit has a fourth total resistance value; the third total resistance value is greater than the fourth total resistance value; the third threshold voltage is less than or equal to the second threshold voltage.

10. A single live wire switch circuit for preventing lamp flash, characterized in that: include: The single live wire off-state power supply circuit according to any one of claims 1 to 9; A rectifier circuit, the rectifier circuit being connected to the front end of the single-live-wire off-state power-taking circuit for preventing lamp flash; An on-state power-taking circuit, the on-state power-taking circuit being connected to the single-live-wire off-state power-taking circuit for preventing light flashing; A control system is provided, wherein the control system is connected to the on-state power-taking circuit and the single-live-wire off-state power-taking circuit for preventing light flashing.

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