Constant current power supply reset detection circuit and LED illumination lamp

Abstract

The utility model provides a constant-current power supply reset detection circuit and an LED lighting lamp, the circuit comprises a constant-current power supply circuit and a reset detection main circuit, the constant-current power supply circuit comprises a bridge rectifier and a transformation coupling, and the reset detection main circuit comprises a single-chip microcomputer reset detection circuit, a DALI controller and a constant-current control chip. The single-chip microcomputer reset detection circuit comprises a voltage dividing sub-resistor, a third resistor, a fourth resistor, a fifth resistor, a triode and a fourth capacitor. When no alternating current is input into the circuit, the constant current control chip can still work normally, the voltage formed by filtering of the fourth capacitor can become 0V when no alternating current is input, the voltage generated by voltage division of the resistor is 0V, the triode is cut off, the AC level of the detection end of the DALI controller can be pulled up to be standard voltage, and the DALI controller works normally. And the constant current control chip can complete the reset action within the specified time through software, and the reset can be completed without waiting for the power failure of the VCC, so that the DALI-2 protocol requirement is met.

Description

Technical Field

[0001] The present disclosure relates to the field of lighting technology, and in particular to a constant current power supply reset detection circuit and an LED lighting fixture. Background Art

[0002] There are many types of constant current dimming products. DALI (Digital Addressable Lighting Interface), as a new intelligent lighting system control protocol, has been widely used in various lighting projects due to its simple structure, easy installation, easy operation, and excellent functions.

[0003] With the widespread adoption of the DALI-2 protocol, market demand for DALI-controlled LED lamps is increasing. The DALI-2 protocol also places strict requirements on power supplies, requiring the power module's MCU to reset within a specified timeframe, such as three seconds, under any load. Because the primary-side constant current solution has a large electrolytic capacitor at the input, and the DALI dimming module's MCU is located on the primary side, the reset time can exceed three seconds when the load is light or no load. This prevents the MCU from resetting within this timeframe, and the lamp therefore fails to comply with the DALI-2 protocol. Utility Model Content

[0004] The purpose of the present disclosure is to overcome the deficiencies in the prior art and to provide a constant current power supply reset detection circuit and an LED lighting fixture that can complete the reset function within a specified time under any load condition.

[0005] The purpose of this disclosure is achieved through the following technical solutions:

[0006] A constant current power supply reset detection circuit includes a constant current power supply circuit and a reset detection circuit. The constant current power supply circuit includes a bridge rectifier and a transformer coupling. The input end of the bridge rectifier is used to connect to AC power, the output end of the bridge rectifier is electrically connected to the input end of the transformer coupling, and the output end of the transformer coupling is used to electrically connect to an LED constant current load. The reset detection circuit includes a single-chip reset detection circuit, a DALI controller, and a constant current control chip. The drain end of the constant current control chip is electrically connected to the input end of the transformer coupling, and the reset end of the constant current control chip is electrically connected to the pulse width modulation enable end of the DALI controller. The single-chip reset detection circuit includes a reset detection circuit, a DALI controller, and a constant current control chip. The drain end of the constant current control chip is electrically connected to the input end of the transformer coupling, and the reset end of the constant current control chip is electrically connected to the pulse width modulation enable end of the DALI controller. The invention comprises a voltage divider resistor, a third resistor, a fourth resistor, a fifth resistor, a transistor and a fourth capacitor, wherein the first end of the voltage divider resistor is connected to the input end of the bridge rectifier, the second end of the voltage divider resistor is respectively connected to the upper half end of the fourth capacitor and the first end of the third resistor, the second end of the third resistor is respectively connected to the first end of the fourth resistor and the control end of the transistor, the second end of the fourth resistor is respectively connected to the lower half end of the fourth capacitor and the second end of the transistor, the lower half end of the fourth capacitor is grounded, the first end of the fifth resistor is used to connect to the standard voltage end, and the second end of the fifth resistor is respectively connected to the first end of the transistor and the detection end of the DALI controller.

[0007] In one embodiment, the voltage divider resistor includes a first resistor and a second resistor, the first end of the first resistor is connected to the input end of the bridge rectifier, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the second resistor is respectively connected to the upper half of the fourth capacitor and the first end of the third resistor.

[0008] In one embodiment, at least one of the first resistor and the second resistor is a variable resistor.

[0009] In one embodiment, the single chip reset detection circuit further includes a second diode, a positive end of the second diode is connected to the live wire input end of the bridge rectifier, and a negative end of the second diode is connected to the first end of the voltage divider resistor.

[0010] In one embodiment, the single chip reset detection circuit further includes a third diode, the positive end of the third diode is connected to the neutral line input end of the bridge rectifier, and the negative end of the third diode is connected to the negative end of the second diode.

[0011] In one embodiment, the fourth capacitor is a high-frequency filter capacitor.

[0012] In one embodiment, the constant current power supply circuit further includes a first capacitor, the upper half of the first capacitor is connected to the positive output terminal of the bridge rectifier, the lower half of the first capacitor is connected to the negative output terminal of the bridge rectifier, and the lower half of the first capacitor is grounded.

[0013] In one embodiment, the constant current power supply circuit further includes a second capacitor, the upper half of the second capacitor is connected to the positive output terminal of the transformer coupling, the lower half of the second capacitor is connected to the negative output terminal of the transformer coupling, and the lower half of the second capacitor is grounded.

[0014] In one embodiment, the constant current power supply circuit further includes a first diode, a positive end of the first diode is connected to the positive output end of the transformer coupling, and a negative end of the first diode is connected to the upper half end of the second capacitor.

[0015] An LED lighting fixture includes the constant current power supply reset detection circuit described in any one of the above embodiments.

[0016] Compared with the prior art, the present disclosure has at least the following advantages:

[0017] When there is no AC input to the circuit, since DALI controllers often have hold-up time requirements, the constant current control chip can still maintain normal operation. The voltage formed by the fourth capacitor filtering will become 0V when there is no AC input. The voltage generated by the voltage divider resistor, the third resistor, and the fourth resistor is also 0V. The transistor is cut off, and the AC level at the detection end of the DALI controller will be pulled up to the standard voltage. After the DALI controller detects the presence of the standard voltage on its AC detection pin, the constant current control chip will complete the reset action within the specified time through software. There is no need to wait until VCC power is lost to complete the reset, and it is not affected by the load, thus meeting the DALI-2 protocol requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present disclosure and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 1 is a circuit schematic diagram of a constant current power supply reset detection circuit in one embodiment;

[0020] Figure 2 for Figure 1 The circuit diagram of the constant current power supply reset detection circuit is shown in FIG.

[0021] Figure numerals: 10, constant current power supply reset detection circuit; 100, constant current power supply circuit; 200, reset detection main circuit; 200A, single-chip microcomputer reset detection circuit; BD1, bridge rectifier; C1, first capacitor; C2, second capacitor; C4, fourth capacitor; D1, first diode; D2, second diode; D3, third diode; H1, DALI controller; R1, first resistor; R2, second resistor; R3, third resistor; R4, fourth resistor; R5, fifth resistor; Q1, transistor; T1, transformer coupling; U1, constant current control chip. DETAILED DESCRIPTION

[0022] To facilitate understanding of the present disclosure, a more comprehensive description of the present disclosure will be provided below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present disclosure. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure.

[0023] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly attached to the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this disclosure pertains. The terms used herein in the specification of this disclosure are intended only to describe specific embodiments and are not intended to limit this disclosure. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0025] In order to better understand the technical solutions and beneficial effects of the present disclosure, the present disclosure is further described in detail below with reference to specific embodiments:

[0026] See also Figure 1 , which is a circuit schematic diagram of a constant current power supply reset detection circuit 10 according to an embodiment of the present invention.

[0027] like Figure 2As shown, a constant current power supply reset detection circuit 10 includes a constant current power supply circuit 100 and a reset detection circuit 200. The constant current power supply circuit 100 includes a bridge rectifier BD1 and a transformer coupling T1. The input end of the bridge rectifier BD1 is used to connect to the AC power, the output end of the bridge rectifier BD1 is electrically connected to the input end of the transformer coupling T1, and the output end of the transformer coupling T1 is used to be electrically connected to the LED constant current load; the reset detection circuit 200 includes a single-chip reset detection circuit 200A, a DALI controller H1 and a constant current control chip U1. The drain end of the constant current control chip U1 is electrically connected to the input end of the transformer coupling T1, and the reset end of the constant current control chip U1 is electrically connected to the pulse width modulation enable end of the DALI controller H1; the single-chip reset detection circuit 200A includes a voltage divider resistor, a third Resistor R3, fourth resistor R4, fifth resistor R5, transistor Q1, and fourth capacitor C4. The first end of the voltage divider resistor is connected to the input terminal of bridge rectifier BD1. The second end of the voltage divider resistor is respectively connected to the upper half of the fourth capacitor C4 and the first end of the third resistor R3. The second end of the third resistor R3 is respectively connected to the first end of the fourth resistor R4 and the control terminal of transistor Q1. The second end of the fourth resistor R4 is respectively connected to the lower half of the fourth capacitor C4 and the second end of the transistor Q1. The lower half of the fourth capacitor C4 is grounded. The first end of the fifth resistor R5 is connected to the standard voltage terminal. The second end of the fifth resistor R5 is respectively connected to the first end of the transistor Q1 and the detection terminal of the DALI controller H1. Furthermore, the voltage value of the standard voltage terminal is 5V.

[0028] In this embodiment, when there is no AC input to the circuit, the constant current control chip U1 can still maintain normal operation, as the DALI controller H1 often has a hold-up time requirement. The voltage filtered by the fourth capacitor C4 becomes 0V when there is no AC input. The voltage divided by the voltage divider resistor, the third resistor R3, and the fourth resistor R4 is also 0V. The transistor Q1 is cut off, and the AC level at the detection terminal of the DALI controller H1 is pulled up to the standard voltage. After the DALI controller H1 detects the standard voltage at its AC detection pin, the constant current control chip U1 completes a reset operation within a specified time through software, without having to wait until VCC power is lost and is not affected by the load, thus meeting the DALI-2 protocol requirements. The voltage divider resistor, the third resistor R3, and the fourth resistor R4 form a voltage divider resistor; the fifth resistor R5 is used to limit the current at the standard voltage terminal, protecting the first terminal of the transistor Q1 and the detection terminal of the DALI controller H1, and preventing current fluctuations from the standard voltage terminal from breaking down and protecting the first terminal of the transistor Q1 and / or the detection terminal of the DALI controller H1.

[0029] It can be understood that when the circuit is connected to AC power, the AC power is sequentially output to the LED constant current load through bridge rectifier BD1 and transformer coupler T1. Furthermore, single-chip microcomputer reset detection circuit 200A also includes a second diode D2 and a third diode D3. The positive terminal of second diode D2 is connected to the live input terminal of bridge rectifier BD1, the negative terminal of second diode D2 is connected to the first end of the voltage divider resistor, the positive terminal of third diode D3 is connected to the neutral input terminal of bridge rectifier BD1, and the negative terminal of third diode D3 is connected to the negative terminal of second diode D2. In this way, the AC power is rectified and filtered into a voltage VO+ through the second diode D2, the third diode D3 and the fourth capacitor C4, and the voltage is divided by the voltage divider resistor, the third resistor R3 and the fourth resistor R4 to generate a voltage Vth. This voltage makes the control terminal of the transistor Q1 at a high level to turn on, and the current at the standard voltage terminal passes through the transistor Q1 and is grounded. At this time, the detection terminal of the DALI controller H1 is in a voltage-free state. After the DALI controller H1 detects that the voltage of its AC detection pin is 0, it drives the constant current control chip U1 to work normally through its pulse width modulation enable terminal PWM-Out enable signal. In this way, the reset function will not be triggered by software. When there is no AC input to the circuit, since the DALI controller H1 often has a maintenance time requirement, The constant current control chip U1 (MCU) can still maintain normal operation. The AC power is rectified and filtered by the second diode D2, the third diode D3, and the fourth capacitor C4 to form a voltage VO+ of 0. The voltage Vth generated by the voltage divider resistor, the third resistor R3, and the fourth resistor R4 is also 0, causing the transistor Q1 to be cut off. The current at the standard voltage end flows through the DALI controller H1. When the DALI controller H1 detects the presence of voltage on its AC detection pin, it drives the constant current control chip U1 to complete the reset work through software. There is no need to wait until the VCC end of the constant current control chip U1 loses power before resetting. It is not affected by the load, so that the reset action can be completed within the specified time when the power is off, meeting the requirements of the DALI-2 protocol.

[0030] In this embodiment, if Figure 2 As shown, the voltage divider resistor includes a first resistor R1 and a second resistor R2. The first end of the first resistor R1 is connected to the input end of the bridge rectifier BD1, the second end of the first resistor R1 is connected to the first end of the second resistor R2, and the second end of the second resistor R2 is respectively connected to the upper half of the fourth capacitor C4 and the first end of the third resistor R3.

[0031] In one embodiment, at least one of the first resistor R1 and the second resistor R2 is a variable resistor. In this embodiment, when one or both of the first resistor R1 and the second resistor R2 are variable resistors, the resistance ratio of the first resistor R1 to the second resistor R2 can be adjusted by adjusting the resistance value of one or both of the first resistor R1 and the second resistor R2, thereby adjusting the voltage divider ratio of the first resistor R1 and the second resistor R2 when the generated voltage VO+ is divided.

[0032] In another embodiment, at least one of the third resistor R3 and the fourth resistor R4 is a variable resistor. In this embodiment, when one or both of the third resistor R3 and the fourth resistor R4 are variable resistors, the resistance ratio of the third resistor R3 to the fourth resistor R4 can be adjusted by adjusting the resistance value of one or both of the third resistor R3 and the fourth resistor R4, thereby adjusting the conduction condition of the transistor Q1 to adapt to a wider range of transistor Q1 models. In this embodiment, the transistor Q1 is an NPN transistor, whose first terminal is the collector, the second terminal is the emitter, and the control terminal is the base.

[0033] In one embodiment, the fourth capacitor C4 is a high-frequency filter capacitor. It is understood that since the fourth capacitor C4 has a relatively small capacitance, typically in the nanofarad range, it can be used to filter high-frequency signals. This also facilitates quickly reducing the voltage formed by the rectification and filtering of the second diode D2, the third diode D3, and the fourth capacitor C4 to 0V when there is no AC input, turning off the transistor Q1 and facilitating a rapid reset of the DALI controller H1 when a voltage is present at its detection terminal AC.

[0034] like Figure 2 As shown, in one embodiment, the constant current power supply circuit 100 further includes a first capacitor C1, the upper half of the first capacitor C1 being connected to the positive output terminal of the bridge rectifier BD1, the lower half of the first capacitor C1 being connected to the negative output terminal of the bridge rectifier BD1, and the lower half of the first capacitor C1 being grounded. It will be understood that when the AC power is rectified and output into DC power by the bridge rectifier BD1, the first capacitor C1 filters the DC power signal, stabilizing the voltage at the input terminal of the transformer coupling T1, thereby preventing voltage fluctuations that would cause the voltage output to the LED constant current load to follow the fluctuations.

[0035] like Figure 2 As shown, in one embodiment, the constant current power supply circuit 100 further includes a second capacitor C2, the upper half of the second capacitor C2 being connected to the positive output terminal of the transformer coupling T1, the lower half of the second capacitor C2 being connected to the negative output terminal of the transformer coupling T1, and the lower half of the second capacitor C2 being grounded. It will be understood that after the input voltage is converted and output by the transformer coupling T1, the output signal is filtered by the second capacitor C2 to stabilize the voltage output to the LED constant current load and prevent voltage fluctuations.

[0036] like Figure 2 As shown, in one embodiment, the constant current power supply circuit 100 further includes a first diode D1, the positive end of the first diode D1 is connected to the positive output end of the transformer coupling T1, and the negative end of the first diode D1 is connected to the upper half end of the second capacitor C2. It can be understood that the first diode D1 is used to rectify the output current to ensure that the output current flows unidirectionally to the LED constant current load, thereby avoiding the situation where the output current flows back and causes damage to the circuit components. In this embodiment, the first diode D1 and the second capacitor C2 constitute a rectifier filter circuit to ensure that the output current can be signal filtered by the second capacitor C2 and output unidirectionally to the LED constant current load.

[0037] The present disclosure further provides an LED lighting fixture, comprising the constant current power supply reset detection circuit 10 in any of the above embodiments.

[0038] Compared with the prior art, the present disclosure has at least the following advantages:

[0039] When there is no AC input to the circuit, the constant current control chip U1 can still maintain normal operation because the DALI controller H1 often has a hold-up time requirement. The voltage formed by the fourth capacitor C4 filtering will become 0V when there is no AC input. The voltage generated by the voltage divider resistor, the third resistor R3 and the fourth resistor R4 is also 0V. The transistor Q1 is cut off, and the AC level of the detection end of the DALI controller H1 will be pulled up to the standard voltage. After the DALI controller H1 detects the presence of the standard voltage on its AC detection pin, the constant current control chip U1 will complete the reset action within the specified time through software. There is no need to wait until VCC power is lost to complete the reset, and it is not affected by the load, thus meeting the DALI-2 protocol requirements.

[0040] The above-described embodiments merely represent several implementation methods of the present disclosure. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the disclosed patent. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the scope of the present disclosure, all of which fall within the scope of protection of the present disclosure. Therefore, the scope of protection of the disclosed patent shall be determined by the appended claims.

Claims

1. A constant current power supply reset detection circuit, characterized in that: Including constant current power supply circuit and reset detection circuit, The constant current power supply circuit includes a bridge rectifier and a transformer coupling, wherein the input end of the bridge rectifier is used to receive alternating current, the output end of the bridge rectifier is electrically connected to the input end of the transformer coupling, and the output end of the transformer coupling is electrically connected to the LED constant current load; The reset detection circuit includes a single-chip reset detection circuit, a DALI controller and a constant current control chip, the drain terminal of the constant current control chip is electrically connected to the input terminal of the transformer coupling, and the reset terminal of the constant current control chip is electrically connected to the pulse width modulation enable terminal of the DALI controller; The single-chip microcomputer reset detection circuit includes a voltage divider resistor, a third resistor, a fourth resistor, a fifth resistor, a transistor and a fourth capacitor. The first end of the voltage divider resistor is connected to the input end of the bridge rectifier, the second end of the voltage divider resistor is respectively connected to the upper half end of the fourth capacitor and the first end of the third resistor, the second end of the third resistor is respectively connected to the first end of the fourth resistor and the control end of the transistor, the second end of the fourth resistor is respectively connected to the lower half end of the fourth capacitor and the second end of the transistor, the lower half end of the fourth capacitor is grounded, the first end of the fifth resistor is used to connect to the standard voltage end, and the second end of the fifth resistor is respectively connected to the first end of the transistor and the detection end of the DALI controller.

2. The constant current power supply reset detection circuit according to claim 1, characterized in that: The voltage divider resistor includes a first resistor and a second resistor, the first end of the first resistor is connected to the input end of the bridge rectifier, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the second resistor is respectively connected to the upper half end of the fourth capacitor and the first end of the third resistor.

3. The constant current power supply reset detection circuit according to claim 2, characterized in that: At least one of the first resistor and the second resistor is a variable resistor.

4. The constant current power supply reset detection circuit according to claim 1, characterized in that: The single chip reset detection circuit further includes a second diode, a positive end of the second diode is connected to the live wire input end of the bridge rectifier, and a negative end of the second diode is connected to the first end of the voltage divider resistor.

5. The constant current power supply reset detection circuit according to claim 4, characterized in that: The single chip reset detection circuit further includes a third diode, a positive end of the third diode is connected to the neutral line input end of the bridge rectifier, and a negative end of the third diode is connected to the negative end of the second diode.

6. The constant current power supply reset detection circuit according to claim 1, characterized in that: The fourth capacitor is a high-frequency filter capacitor.

7. The constant current power supply reset detection circuit according to claim 1, characterized in that: The constant current power supply circuit also includes a first capacitor, the upper half of the first capacitor is connected to the positive output terminal of the bridge rectifier, the lower half of the first capacitor is connected to the negative output terminal of the bridge rectifier, and the lower half of the first capacitor is grounded.

8. The constant current power supply reset detection circuit according to claim 1, characterized in that: The constant current power supply circuit also includes a second capacitor, the upper half of the second capacitor is connected to the positive output terminal of the transformer coupling, the lower half of the second capacitor is connected to the negative output terminal of the transformer coupling, and the lower half of the second capacitor is grounded.

9. The constant current power supply reset detection circuit according to claim 8, characterized in that: The constant current power supply circuit further includes a first diode, a positive end of the first diode is connected to the positive output end of the transformer coupling, and a negative end of the first diode is connected to the upper half end of the second capacitor.

10. An LED lighting fixture, characterized in that: The invention comprises the constant current power supply reset detection circuit according to any one of claims 1 to 9.

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