Non-isolated LED driving power supply afterglow removal control circuit

Abstract

The utility model discloses a non-isolated LED driving power supply afterglow removal control circuit. A voltage input end; the auxiliary power supply is connected with the voltage input end; the relay control circuit is used for receiving the control signal from the dimming circuit and sending a signal to a relay; the coil end of the relay is connected with the relay control circuit, one end of the conducting end of the relay is connected with the voltage input end, and the other end of the relay is used for supplying power to the main circuit. The LED driving circuit mainly solves the problems that during dimming and extinguishing, stray capacitance exists between an LED and an LED board heat dissipation board, and the LED and the input circuit are not disconnected, so that micro current is generated, and micro light is emitted. The non-isolated driving power supply has an afterglow removing effect on the non-isolated driving power supply during dimming and extinguishing, the problem of afterglow during dimming and extinguishing of the non-isolated driving power supply is avoided, and when dimming and extinguishing are carried out, connection between the input voltage and the driving power supply main circuit is cut off, so that the effect of no afterglow during dimming and extinguishing of the non-isolated driving power supply is realized.

Description

Technical Field

[0001] The utility model relates to the field of LED power supplies, in particular to a non-isolated LED driving power supply afterglow removal control circuit. Background Art

[0002] As technology continues to develop and mature, LED lighting applications are becoming more and more extensive. The use of non-isolated power supplies is also becoming more and more widespread, and the places of application are becoming more and more diverse. When used in the field of plant lighting, there are strict requirements for low light, which can cause serious problems for the growth of some sensitive plants.

[0003] At present, the general practice in the industry to prevent afterglow when dimming non-isolated driver power is to cut off the connection between the output and the LED through the control circuit when dimming is turned off, so that the LED does not produce dim light. In this way, although the connection between the output and the LED is cut off, there is a problem of incomplete cut-off. With the continuous improvement of LED light efficiency, a very small current can emit dim light, and the problem of afterglow may still exist. Utility Model Content

[0004] In order to solve the above problems, the present technical solution provides a non-isolated LED drive power supply afterglow removal control circuit.

[0005] To achieve the above purpose, the technical solution is as follows:

[0006] A non-isolated LED driving power supply afterglow removal control circuit, comprising:

[0007] Voltage input terminal;

[0008] an auxiliary power supply connected to the voltage input terminal;

[0009] A relay control circuit receives a control signal from the dimming circuit and sends a signal to the relay;

[0010] The relay has a coil end connected to the relay control circuit, a conduction end connected to the voltage input end, and the other end used to supply power to the main circuit.

[0011] In some embodiments, the relay control circuit includes:

[0012] The transistor Q16 has a base receiving a control signal CCO of the dimming circuit, an emitter being grounded, and a collector being connected to one end of the light-emitting end of the optocoupler U7;

[0013] The other end of the optical coupler U7 receives a voltage, the emitter is grounded, and the collector receives the voltage VCCA;

[0014] The transistor Q24 has a base which also receives the voltage VCCA, an emitter which is grounded, and a collector which is connected to the signal VB.

[0015] In some embodiments, the collector of the transistor Q24 is connected to a diode D33.

[0016] In some embodiments, further comprising:

[0017] The transistor Q23 has a base connected to the signal VB, a collector also receiving the voltage VCCA, and an emitter connected to the coil end of the relay.

[0018] In some embodiments, the voltage VCCA comes from an auxiliary power supply.

[0019] The beneficial effects of this application are:

[0020] This application mainly solves the problem that when the light is dimmed and turned off, there is parasitic capacitance between the LED and the heat sink of the LED board, and it is not disconnected from the input circuit, resulting in a tiny current and faint light. This application plays a role in removing afterglow when the non-isolated driving power supply is dimmed and turned off, avoiding the problem of afterglow when the non-isolated driving power supply is dimmed and turned off. When the dimming is turned off, the connection between the input voltage and the main circuit of the driving power supply is cut off, thereby achieving the effect of no afterglow when the non-isolated driving power supply is dimmed and turned off. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the following briefly introduces the drawings required for describing the embodiments.

[0022] Figure 1 It is a schematic diagram of the structure of an embodiment of the utility model;

[0023] Figure 2 It is a block diagram of an embodiment of the utility model. DETAILED DESCRIPTION

[0024] In order to make the technical problems, technical solutions and beneficial effects solved by the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0025] Please refer to Figure 1-2 As shown, a non-isolated LED driving power supply afterglow removal control circuit includes:

[0026] Voltage input terminal;

[0027] an auxiliary power supply connected to the voltage input terminal;

[0028] A relay control circuit receives a control signal from the dimming circuit and sends a signal to the relay;

[0029] The relay has a coil end connected to the relay control circuit, a conduction end connected to the voltage input end, and the other end used to supply power to the main circuit.

[0030] When the dimming is turned off, the relay is used to disconnect the main power circuit from the input grid, so that the input and the LED are completely cut off, and no afterglow path is generated, thus completely solving the afterglow problem.

[0031] In this embodiment, the relay control circuit includes:

[0032] The transistor Q16 has a base receiving a control signal CCO of the dimming circuit, an emitter being grounded, and a collector being connected to one end of the light-emitting end of the optocoupler U7;

[0033] The other end of the optical coupler U7 receives a voltage, the emitter is grounded, and the collector receives the voltage VCCA;

[0034] The transistor Q24 has a base which also receives the voltage VCCA, an emitter which is grounded, and a collector which is connected to the signal VB.

[0035] When the control signal CCO of the dimming circuit is at a high level, the transistor Q16 is turned on, so that the light emitting diode of the optocoupler U7 lights up, and the voltage VCCA is grounded through the optocoupler U7, so that the base voltage of the transistor Q24 drops and is then cut off.

[0036] In this embodiment, the collector of the transistor Q24 is connected to a diode D33 .

[0037] In some embodiments, further comprising:

[0038] The transistor Q23 has a base connected to the signal VB, a collector also receiving the voltage VCCA, and an emitter connected to the coil end of the relay.

[0039] When transistor Q24 is turned off, the voltage of signal VB decreases, so that transistor Q23 is also turned off, thereby disconnecting the power supply between voltage VCCA and the coil of the relay, so that the relay disconnects the voltage input of the neutral and live wires.

[0040] In this embodiment, the voltage VCCA comes from an auxiliary power supply.

[0041] How this application works:

[0042] When the power supply is powered on, the circuit supplies power to the relay through the auxiliary power supply VCCA, and the relay is closed. At this time, the input end of the power supply is connected to the main circuit of the power supply through the relay, and the main circuit of the power supply can work and output voltage and current.

[0043] When the dimming signal is normal, the CCO signal outputs a high level, Q16 is turned on, U7 works, the base voltage of Q24 drops and cannot be turned on, Q24 is not turned on, the voltage at VB returns to normal, the power supply of the relay is restored, the relay is closed, and the entire circuit returns to normal operation.

[0044] When the dimming is turned off, the CCO signal outputs a low level, Q16 does not conduct, the U7 optocoupler cannot work, the base voltage of Q24 rises to the conduction voltage, and the VB voltage is pulled down through D33, so that the relay cannot reach the working voltage, and the relay is disconnected. At this time, the power input terminal is disconnected from the main circuit of the power supply, the main circuit of the power supply does not work, and the LED is also disconnected from the input terminal. Moreover, the signal ground here is GND3, which has no electrical connection with the signal ground GND of the main circuit of the power supply, no loop is formed, and no current is generated. And because the relay is physically disconnected, the main circuit of the power supply can be completely separated from the input terminal, so that there is no afterglow when the dimming is turned off.

[0045] The key point of this application is that when the dimming is turned off, the relay in the circuit is disconnected to completely disconnect the product from the input voltage, thereby achieving the function of no afterglow. It can be applied in various places. This application uses a simple circuit to achieve the function of no afterglow when the non-isolated driving power supply is dimmed off.

[0046] The above description is only a preferred embodiment of the present application and is not intended to limit the scope of implementation of the present application. Other principles and basic structures that are the same or similar to those of the present application are within the protection scope of the present application.

Claims

1. A non-isolated LED drive power supply afterglow removal control circuit, characterized in that: include; Voltage input terminal; an auxiliary power supply connected to the voltage input terminal; A relay control circuit receives a control signal from the dimming circuit and sends a signal to the relay; The relay has a coil end connected to the relay control circuit, a conduction end connected to the voltage input end, and the other end used to supply power to the main circuit.

2. A non-isolated LED driving power supply afterglow removal control circuit according to claim 1, characterized in that: The relay control circuit comprises: The transistor Q16 has a base receiving a control signal CCO of the dimming circuit, an emitter being grounded, and a collector being connected to one end of the light-emitting end of the optocoupler U7; The other end of the optical coupler U7 receives a voltage, the emitter is grounded, and the collector receives the voltage VCCA; The transistor Q24 has a base which also receives the voltage VCCA, an emitter which is grounded, and a collector which is connected to the signal VB.

3. A non-isolated LED driving power supply afterglow removal control circuit according to claim 2, characterized in that: The collector of the transistor Q24 is connected to a diode D33 .

4. A non-isolated LED driving power supply afterglow removal control circuit according to claim 2, characterized in that: Also includes; The transistor Q23 has a base connected to the signal VB, a collector also receiving the voltage VCCA, and an emitter connected to the coil end of the relay.

5. A non-isolated LED driving power supply afterglow removal control circuit according to claim 4, characterized in that: The voltage VCCA comes from an auxiliary power supply.

Images