CN217957368U

CN217957368U - Multi-path constant-current common-anode dimming power supply

Info

Publication number: CN217957368U
Application number: CN202221743304.3U
Authority: CN
Inventors: 雷明耿
Original assignee: Zhuhai Shengchang Electronics Co ltd
Current assignee: Zhuhai Shengchang Electronics Co ltd
Priority date: 2022-07-05
Filing date: 2022-07-05
Publication date: 2022-12-02
Anticipated expiration: 2032-07-05

Abstract

The utility model discloses a public positive dimming power supply of multichannel constant current, including AC-DC module and a plurality of dimming output circuit, every dimming output circuit includes DC-DC module and output terminal, the LED lamp can insert output terminal, the input of AC-DC module inserts external power supply, the output of AC-DC module is connected with the positive pole of the output terminal in every dimming output circuit, the negative pole of output terminal is connected with DC-DC module, the earthing terminal ground connection of AC-DC module and DC-DC module; the common-anode circuit structure with the multi-path constant current output is realized through the structure, and the common-anode circuit structure has the advantages of simple circuit connection, small number of devices, stable performance and smooth dimming, and has very good practicability.

Description

Multi-path constant-current common-anode dimming power supply

Technical Field

The utility model relates to a LED drive power supply and switching power supply technical field of adjusting luminance, in particular to multichannel constant current is positive power supply of adjusting luminance altogether.

Background

The LED driving power supply and the switching power supply are widely applied in the market at present, the constant-current dimming power supply is popular due to high efficiency and small heat productivity of a lamp, for a color temperature adjustable product of the constant-current LED dimming power supply, multiple paths of constant currents are products which cannot be lacked by high-end lighting, and for the LED power supply with multiple paths of constant currents, compared with a common anode and a common cathode, the module structure is relatively simple, and cost is relatively reduced due to the fact that an isolation driving module is omitted, and miniaturization of the product is facilitated; therefore, a multi-path constant-current common-anode dimming power supply is provided.

SUMMERY OF THE UTILITY MODEL

The utility model discloses aim at solving one of the technical problem that exists among the prior art at least. Therefore, the utility model provides a multichannel constant current is positive altogether's light modulation power supply.

The utility model discloses a technical scheme that its technical problem was solved to an embodiment adopted is: a multi-path constant-current common-anode dimming power supply comprises an AC-DC module and a plurality of dimming output circuits, wherein each dimming output circuit comprises a DC-DC module and an output terminal, an LED lamp can be connected into the output terminal, the input end of the AC-DC module is connected into an external power supply, the output end of the AC-DC module is connected with the positive electrode of the output terminal in each dimming output circuit, the negative electrode of the output terminal is connected with the DC-DC module, and the grounding ends of the AC-DC module and the DC-DC module are grounded.

Further, the AC-DC module includes an EMI filter module, a rectifier bridge BD1, a PWM control chip U1, a MOS transistor Q1, a capacitor EC1, a resistor R3, and a transformer T1 having a primary winding T1A and a secondary winding T1B, an external power source is connected to the rectifier bridge BD1 through the EMI filter module, an output end of the rectifier bridge BD1 is connected to one end of the primary winding T1A of the transformer T1 and the PWM control chip U1, the other end of the primary winding T1A of the transformer T1 is connected to a drain of the MOS transistor Q1, a gate of the MOS transistor Q1 is connected to the PWM control chip U1, a source of the MOS transistor Q1 is grounded through the resistor R3, a power supply end of the PWM control chip U1 is connected to a power supply, one end of the secondary winding T1B of the transformer T1 is connected to an anode of the capacitor EC1 and an anode of an output terminal, and the other end of the secondary winding T1B of the transformer T1 is connected to a cathode and an earth end of the capacitor EC 1.

Further, the DC-DC module includes a dimming control chip U2, an inductor L1, an MOS transistor Q2, a diode D3, and a resistor R1, an anode of the output terminal is connected to the AC-DC module and a cathode of the diode D3, a cathode of the output terminal is connected to one end of the resistor R1 and the dimming control chip U2, another end of the resistor R1 is connected to one end of the inductor L1 and the dimming control chip U2, another end of the inductor L1 is connected to a drain of the MOS transistor Q2 and an anode of the diode D3, a gate of the MOS transistor Q2 is connected to the dimming control chip U2, and a source of the MOS transistor Q2 is grounded.

The utility model has the advantages that: a multi-path constant-current common-anode dimming power supply comprises an AC-DC module and a plurality of dimming output circuits, wherein each dimming output circuit comprises a DC-DC module and an output terminal, an LED lamp can be connected into the output terminal, the input end of the AC-DC module is connected with an external power supply, the output end of the AC-DC module is connected with the positive electrode of the output terminal in each dimming output circuit, the negative electrode of the output terminal is connected with the DC-DC module, and the grounding ends of the AC-DC module and the DC-DC module are grounded; the common-anode circuit structure with the multi-path constant current output is realized through the structure, and the common-anode circuit structure has the advantages of simple circuit connection, small number of devices, stable performance and smooth dimming, and has very good practicability.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a schematic block diagram of a multi-path constant current common-anode dimming power supply;

FIG. 2 is a first partial circuit diagram of an embodiment of a multi-path constant current common anode dimming power supply;

fig. 3 is a second partial circuit diagram of an embodiment of a multi-path constant current common anode dimming power supply.

Detailed Description

This section will describe in detail the embodiments of the present invention, preferred embodiments of the present invention are shown in the attached drawings, which are used to supplement the description of the text part of the specification with figures, so that one can intuitively and vividly understand each technical feature and the whole technical solution of the present invention, but they cannot be understood as the limitation of the protection scope of the present invention.

In the description of the present invention, a plurality of means are two or more, and the terms greater than, less than, exceeding, etc. are understood as excluding the number, and the terms greater than, less than, etc. are understood as including the number. If the first and second are described for the purpose of distinguishing technical features, they are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.

In the description of the present invention, it should be understood that the orientation or positional relationship indicated with respect to the orientation description, such as up, down, front, rear, left, right, etc., is based on the orientation or positional relationship shown in the drawings, and is only for convenience of description and simplification of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the present invention, unless otherwise explicitly defined, the terms "set," "mounted," "connected," and the like are to be understood in a broad sense, and may be directly connected or indirectly connected through an intermediate medium, for example; can be fixedly connected, can also be detachably connected and can also be integrally formed; may be a mechanical connection; either internal to the two elements or in an interactive relationship of the two elements. The technical field can reasonably determine the specific meaning of the words in the utility model by combining the specific content of the technical scheme.

Referring to fig. 1 to 3, a multi-path constant-current common-anode dimming power supply includes an AC-DC module 10 and a plurality of dimming output circuits 20, each dimming output circuit 20 includes a DC-DC module 21 and an output terminal 22, an led lamp is connected to the output terminal 22, an input terminal of the AC-DC module 10 is connected to an external power supply, an output terminal of the AC-DC module 10 is connected to an anode of the output terminal 22 in each dimming output circuit 20, a cathode of the output terminal 22 is connected to the DC-DC module 21, and grounding terminals of the AC-DC module 10 and the DC-DC module 21 are grounded.

The AC-DC module 10 includes an EMI filter module 11, a rectifier bridge BD1, a PWM control chip U1, a MOS transistor Q1, a capacitor EC1, a resistor R3, and a transformer T1 having a primary winding T1A and a secondary winding T1B, an external power source is connected to the rectifier bridge BD1 through the EMI filter module 11, an output end of the rectifier bridge BD1 is connected to one end of the primary winding T1A of the transformer T1 and the PWM control chip U1, the other end of the primary winding T1A of the transformer T1 is connected to a drain of the MOS transistor Q1, a gate of the MOS transistor Q1 is connected to the PWM control chip U1, a source of the MOS transistor Q1 is grounded through the resistor R3, a power supply end of the PWM control chip U1 is connected to the power source, one end of the secondary winding T1B of the transformer T1 is connected to an anode of the capacitor EC1 and an anode of the output terminal 22, and the other end of the secondary winding T1B of the transformer T1 is connected to a cathode and a ground of the capacitor EC 1.

The DC-DC module 21 includes a dimming control chip U2, an inductor L1, a MOS transistor Q2, a diode D3, and a resistor R1, the positive electrode of the output terminal 22 is connected to the AC-DC module 10 and the negative electrode of the diode D3, the negative electrode of the output terminal 22 is connected to one end of the resistor R1 and the dimming control chip U2, the other end of the resistor R1 is connected to one end of the inductor L1 and the dimming control chip U2, the other end of the inductor L1 is connected to the drain of the MOS transistor Q2 and the positive electrode of the diode D3, the gate of the MOS transistor Q2 is connected to the dimming control chip U2, and the source of the MOS transistor Q2 is grounded.

The utility model discloses a theory of operation as follows:

when a system is powered ON, AC alternating current is rectified into direct current through the rectifier bridge BD1 after passing through the EMI filter module 11, the capacitor CP1 mainly functions to filter high-frequency components in steamed bread waves, the PWM control chip U1 starts to work after a high-voltage starting pin is switched ON, the MOS tube Q1 is driven to enter an alternative ON/OFF state, when the MOS tube Q1 is in an ON state, the primary winding T1A of the transformer T1 starts to store energy, and when the MOS tube Q1 is switched OFF, the energy stored in the primary winding T1A of the transformer T1 is released through the secondary winding T1B of the transformer T1.

When the main loop works stably, the ratio of the voltages of the primary winding T1A of the transformer T1 and the secondary winding T1B of the transformer T1 is equal to the ratio of the number of turns of the primary winding and the secondary winding, so that a stable voltage source is presented on EC1, and EC1 is used as the energy input of the post-stage dimming.

The dimming control chip U2 is taken as an example for explanation: in the dimming circuit, in the switching-on stage of the MOS transistor Q2, energy passes through the anode of the capacitor EC1, the anode of the external connection LED lamp and the anode of the output terminal, and then returns to the cathode of the capacitor EC1 through the cathode of the LED lamp, the detection resistor R1, the inductor L1 and the MOS transistor Q2, and in the switching-off stage of the MOS transistor Q2, energy returns to the anode of the output terminal through the diode D3 from the drain of the MOS transistor Q2 to complete follow current.

For the power supply of the dimming control chip U2, the power supply is taken from Vout1-, the dimming control chip U2 has a wide power supply range, generally 6-60V, the internal part of the dimming control chip U2 is subjected to voltage reduction, the power supply is supplied for the internal reference and functional module, and a power supply of about 6V is provided for the internal totem-pole structure driving MOS, so that an external auxiliary power supply winding is not needed to provide energy, and when the LED light source is in no load, the dimming control chip U2 basically does not consume energy due to the fact that no external LED light source forms a loop, and low power consumption or even zero power consumption is further realized.

For the current detection structure, it can be seen from the diagram that the current detection structure is high-end current detection, which has the advantage that the current detection resistor exists at both the turn-on time of the MOS transistor Q2 and the turn-off time of the MOS transistor Q2, i.e., the follow current time, so that the dimming control chip U2 can monitor the current of the inductor L1 in real time no matter at the turn-on stage or the turn-off stage of the MOS transistor Q2, and accurately control the turn-on of the MOS transistor Q2 according to the upper and lower current limits of the inductor L1.

For the multi-path constant current power supply with the circuit structure, the output characteristic is 3V to (Vcc-6V), wherein Vcc is the maximum power supply voltage of the dimming control chip U2.

The invention has the advantages that: the common-anode circuit structure with multi-path constant current output is realized by using the IC through specific circuit connection, and has the advantages of simple circuit connection, small device quantity, stable performance and smooth dimming, and has very good practicability.

Of course, the present invention is not limited to the above-mentioned embodiments, and those skilled in the art can make equivalent modifications or substitutions without departing from the spirit of the present invention, and such equivalent modifications and substitutions are included in the scope defined by the claims of the present application.

Claims

1. A multi-path constant-current common-anode dimming power supply is characterized in that: the LED lamp dimming circuit comprises an AC-DC module (10) and a plurality of dimming output circuits (20), wherein each dimming output circuit (20) comprises a DC-DC module (21) and an output terminal (22), an LED lamp can be connected to the output terminal (22), the input end of the AC-DC module (10) is connected to an external power supply, the output end of the AC-DC module (10) is connected with the positive pole of the output terminal (22) in each dimming output circuit (20), the negative pole of the output terminal (22) is connected with the DC-DC module (21), and the grounding ends of the AC-DC module (10) and the DC-DC module (21) are grounded.

2. The multi-path constant-current common-anode dimming power supply according to claim 1, characterized in that: the AC-DC module (10) comprises an EMI filtering module (11), a rectifier bridge BD1, a PWM control chip U1, an MOS tube Q1, a capacitor EC1, a resistor R3 and a transformer T1 with a primary winding T1A and a secondary winding T1B, wherein an external power supply is connected with the rectifier bridge BD1 through the EMI filtering module (11), the output end of the rectifier bridge BD1 is connected with one end of the primary winding T1A of the transformer T1 and the PWM control chip U1, the other end of the primary winding T1A of the transformer T1 is connected with the drain electrode of the MOS tube Q1, the grid electrode of the MOS tube Q1 is connected with the PWM control chip U1, the source electrode of the MOS tube Q1 is grounded through the resistor R3, the power supply end of the PWM control chip U1 is connected with the power supply, one end of a secondary winding T1B of the transformer T1 is respectively connected with the positive electrode of the capacitor EC1 and the positive electrode of an output terminal (22), and the other end of the secondary winding T1B of the transformer T1 is respectively connected with the negative electrode and the grounding end of the capacitor EC 1.

3. A multi-path constant-current common-anode dimming power supply according to claim 1, wherein: the DC-DC module (21) comprises a dimming control chip U2, an inductor L1, an MOS tube Q2, a diode D3 and a resistor R1, the anode of an output terminal (22) is respectively connected with the AC-DC module (10) and the cathode of the diode D3, the cathode of the output terminal (22) is respectively connected with one end of the resistor R1 and the dimming control chip U2, the other end of the resistor R1 is respectively connected with one end of the inductor L1 and the dimming control chip U2, the other end of the inductor L1 is respectively connected with the drain electrode of the MOS tube Q2 and the anode of the diode D3, the grid electrode of the MOS tube Q2 is connected with the dimming control chip U2, and the source electrode of the MOS tube Q2 is grounded.