CN201976288U - Drive power supply for LED illuminating light - Google Patents

Abstract

The utility model discloses a drive power supply for LED illuminating lights. The alternating input end of the drive power supply is connected with a fuse resistance (F1) in series and a zinc oxide varistor (R1) in parallel, then with a rectified circuit and a winding of transformer (T1), a circuit in series, a power switch tube (Q1)and a resistance to check currents (R3). The drive circuit of the power switch tube comprises a control (IC1), diodes (D3), a resistance (R2) and another winding of transformer (T1). The constant flow control of the whole circuit is done by resistance (R3). When the current in LED light beads reaches a certain value, the voltage on the resistance (R3) will trigger the control (IC1) to shut off the power switch tube to keep the current constant in the LED light beads in series. The utility model adopts a non-segregated buck-boost switch power and takes feedback auxiliary drive windings to improve the efficiency of the drive power supply of the LED lights.

Description

LED lighting driver power supply

technical field

The utility model relates to a driving power supply of a lamp, in particular to a driving power supply of an LED lighting lamp.

Background technique

At present, there are various types of driving power supplies for LED lighting lamps on the market, among which there are driving power supplies using a resistance-capacitance step-down method, and there are also driving power supplies using a linear power supply step-down method. However, these types of driving power sources will cause relatively large power loss, and cannot achieve a real energy-saving effect.

There is also a way of using isolated LED lighting to drive the power supply on the market, but the circuit is complicated, more components are used, the reliability is shorter, the life is shorter, and the cost is higher.

There is also a non-isolated LED lighting driving power supply on the market. Because it does not add a feedback auxiliary driving winding, its driving loss is relatively large, which reduces the efficiency of the entire driving power supply.

The traditional driving power supply of LED lighting adopts the method of rectifier bridge and electrolytic capacitor filter. Because the life of electrolytic capacitor is very short, it seriously affects the long life of LED lamps.

Utility model content

The purpose of this utility model is to provide a solution to the shortage of the existing LED lamp drive power supply, using a non-isolated buck-boost switch to turn off the power supply, adding feedback auxiliary drive windings, improving the efficiency of the entire LED lamp drive power supply, and using a long-life Film capacitors replace electrolytic capacitors with short lifespans, and LED lighting driver power supplies that give full play to the advantages of long lifespans of LED lamp beads.

In order to solve the above-mentioned technical problems, the technical solution adopted by the utility model is: the LED lighting lamp drive power supply, the AC input terminal is connected in series with a fuse resistor F1, and at the same time, a zinc oxide varistor R1 is connected in parallel, and then connected to the rectifier circuit, and then connected to the transformer T1 One winding, LED series circuit, power switch tube Q1 and resistor R3 for detecting current; the driving circuit of the power switch tube is composed of control IC1, diode D3, resistor R2, and another winding of transformer T1. The constant current control of the whole circuit is controlled by When the current in the LED lamp bead reaches a certain value, the voltage on the resistor R3 will trigger the control IC1 to turn off the power switch tube to achieve a constant current in the series LED lamp bead.

The control IC1 is a PWM control integrated circuit.

The control IC1 is a PFM control integrated circuit.

The control IC1 is a self-excited oscillation control circuit.

A rectification filter capacitor C1 is connected between the two output terminals of the rectification circuit, and the rectification filter capacitor C1 is a metallized film capacitor or an electrolytic capacitor.

Due to the above-mentioned circuit structure, the utility model has the following beneficial effects:

1. The use of feedback auxiliary drive windings can effectively reduce the drive loss of the LED drive power supply and increase the reliability of the drive.

2. Using multiple inductors and transformers in series can effectively reduce the volume and installation height of the LED lamp drive power supply and increase the power density of the LED lamp drive power supply.

3. PWM and PFM control integrated circuits can be used flexibly, and low-cost self-excited oscillation control methods can also be used, which effectively reduces the cost of LED drive power.

4. Replace the electrolytic capacitors used for rectification and filtering with film capacitors to improve the life of LED lighting fixtures.

Description of drawings

Fig. 1 is a circuit diagram of Embodiment 1 of a driving power supply for an LED energy-saving lamp.

Fig. 2 is a circuit diagram of the second embodiment of the driving power supply for LED energy-saving lamps.

Fig. 3 is a circuit diagram of Embodiment 3 of the drive power supply for LED energy-saving lamps.

Detailed ways

Below in conjunction with accompanying drawing, the specific embodiment of the present utility model is described in further detail.

Embodiment one

As shown in Figure 1, in the LED lighting driving power supply in the first embodiment of the utility model, a fuse resistor F1 is connected in series at the AC input terminal for overcurrent protection, and a zinc oxide varistor R1 is connected in parallel for surge voltage absorption, and then Connect to a bridge rectifier circuit composed of four diodes D, then connect in series with inductor L1 to filter out high-frequency harmonics, and filter through capacitor C1, then connect a winding of transformer T1, LED1, LED2...LEDn series circuit , the power switch tube Q1 and the resistor R3 for detecting the current, the driving circuit of the power switch tube is composed of the control IC1, the diode D3, the resistor R2, and another winding of the transformer T1. The constant current control of the whole circuit is carried out by the resistor R3. When the current in the LED lamp bead reaches a certain value, the voltage on the resistor R3 will trigger the control IC1 to turn off the power switch tube to achieve the constant current in the series LED lamp bead.

Resistor R2 is connected between the rectified output voltage and control IC1 to provide the base starting voltage or starting current for the power switch tube Q1 and change the switch tube Q1 from the cut-off state to the conduction state. At this time, in the feedback auxiliary winding of the transformer T1 An induced current is generated, and the induced current provides power to the control circuit IC1 through the diode D3, and provides a driving current for driving the switching tube, so as to improve the overall efficiency of the driving power supply.

Embodiment two

As shown in Figure 2, in the driving power supply for LED lighting lamps in the second embodiment of the utility model, a fuse resistor F1 is connected in series at the AC input terminal for overcurrent protection, and a zinc oxide varistor R1 is connected in parallel for surge voltage absorption, and then Connect to the half-wave rectifier circuit composed of diode D1, then connect the current limiting resistor R4 in series, and then connect a winding of the transformer T1, LED1, LED2... LEDn series circuit, power switch tube Q1 and resistor R3 for detecting current, power switch The drive circuit of the tube is composed of control IC1, diode D3, resistor R2, and another winding of transformer T1. The constant current control of the whole circuit is carried out by the resistor R3. When the current in the LED lamp bead reaches a certain value, the voltage on the resistor R3 will trigger the control IC1 to turn off the power switch tube to achieve the constant current in the series LED lamp bead. D4 plays the role of reverse voltage protection.

Resistor R2 is connected between the rectified output voltage and control IC1 to provide the base start-up voltage or start-up current for the power switch tube Q1, and change the switch tube Q1 from the cut-off state to the conduction state. At this time, the feedback auxiliary winding of T1 generates The induced current provides power to the control IC1 through the diode D3, and provides the driving current to drive the switching tube, so as to improve the overall efficiency of the driving power supply.

Embodiment three

As shown in Figure 3, in the driving power supply for LED lighting lamps in the third embodiment of the utility model, a fuse resistor F1 is connected in series at the AC input terminal for overcurrent protection, and a zinc oxide varistor R1 is connected in parallel for surge voltage absorption, and then Connect to a bridge rectifier circuit composed of four diodes D, filter through capacitor C1, and then connect a series circuit of inductors L1, L2...Ln, a winding of transformer T1, a series circuit of LED1, LED2...LEDn, and a power switch tube Q1 and the resistor R3 for detecting the current, the driving circuit of the power switch tube is composed of the control IC1, the diode D3, the resistor R2, and another winding of the transformer T1. The constant current control of the whole circuit is carried out by the resistor R3. When the current in the LED lamp bead reaches a certain value, the voltage on the resistor R3 will trigger the control IC1 to turn off the power switch tube to achieve the constant current in the series LED lamp bead.

Resistor R2 is connected between the rectified output voltage and control IC1 to provide the base start-up voltage or start-up current for the power switch tube Q1, and change the switch tube Q1 from the cut-off state to the conduction state. At this time, the feedback auxiliary winding of T1 generates The induced current provides power to the control IC1 through the diode D3, and provides the driving current to drive the switching tube, so as to improve the overall efficiency of the driving power supply.

The transformer in the example shown in Fig. 3 adopts the method of connecting multiple inductors in series with a single transformer to reduce the volume or height of the transformer T1.

The control IC1 may adopt a general PWM control integrated circuit, or a general PFM control integrated circuit, or a self-excited oscillation control method.

When the utility model works, the rectifier circuit is filtered by the inductor L1 and the capacitor C1 to provide the output loop (series LED loop), the transformer T1, and the power switch tube Q1 to provide DC high-voltage working voltage.

This DC high-voltage working voltage provides the base start-up voltage or start-up current for the power switch tube Q1 through the start-up resistor R2, and changes the switch tube Q1 from the cut-off state to the conduction state. At this time, LED1, LED2, LED3...LEDn circuit, transformer T1 ( Or inductance L1, L2, L3...Ln and T1 loop), this current will increase linearly with the continuation of the switch tube turn-on time, and at the same time, an induced current will be generated in the feedback auxiliary winding of the transformer T1, and this induced current provides power To control IC1, and provide the drive current to drive the switch tube.

The current in the switch tube Q1 (that is, the current in the LED loop and the series inductor, and the transformer loop) passes through the resistor R3 and generates a voltage across the resistor R3. As the LED loop current increases linearly, the voltage across the resistor R3 is also linear increase, when the voltage across the resistor R3 exceeds the reference comparison voltage of the control IC1, the output pin of the drive switch tube of the control IC1 outputs a low level, so that the switch tube Q1 is turned off.

After the switch tube Q1 is turned off, the current of the transformer T1 (or the series circuit of the inductors L1, L2, L3.... Ln and the transformer T1) cannot change abruptly. To continue to flow, the current of the transformer T1 (or the inductors L1, L2, L3.... Ln and The transformer T1 series circuit) changes the voltage direction, and the diode D2, and LED1, LED2, LED3... LEDn generate a closed circuit, and the current is in this by the transformer T1 (or the inductor L1, L2, L3.... Ln and the transformer T1 series circuit) and the diode D2, and LED1, LED2, LED3...LEDn generate a closed loop and continue to flow, outputting LED1, LED2, LED3. . LEDn continues to have current, which decreases linearly.

When the current in output LED1, LED2, LED3...LEDn decreases to a certain level, the control IC1 outputs the driving signal again to drive the switch tube Q1, then LED1, LED2, LED3...LEDn, transformer T1 (or inductors L1, L2, L3... .Ln and the transformer T1 series loop) bear the forward voltage again, and the current in the loop continues to increase linearly... Such a cycle works, and the LED1, LED2, LED3...LEDn, transformer T1 (or inductor L1, L2, L3... . Ln and transformer T1 series loop) provide current.

The control of the constant current value is controlled by the value of the resistor R3.

In a word, although the utility model has exemplified the above-mentioned preferred embodiments, it should be noted that although those skilled in the art can make various changes and modifications, unless such changes and modifications deviate from the scope of the utility model, otherwise all It should be included in the protection scope of the present utility model.

Claims (6)

1. LED illuminating lamp driving power, it is characterized in that: ac input end is in series with fuse resistance (F1), be parallel with Zinc-oxide piezoresistor (R1) simultaneously, insert rectification circuit then, connect the resistance (R3) of a winding, LED series circuit, power switch pipe (Q1) and the detection electric current of transformer (T1) again; The drive circuit of power switch pipe is by control (IC1), diode (D3), resistance (R2), another winding of transformer (T1) is formed, the constant current control of entire circuit is undertaken by resistance (R3), when the electric current in the LED lamp pearl reached certain value, the voltage on the resistance (R3) will trigger control (IC1) switch-off power switching tube to reach the constant of electric current in the series LED lamp pearl.

2. according to the described LED illuminating lamp of claim 1 driving power, it is characterized in that: described control (IC1) is the PWM control integrated circuit.

3. according to the described LED illuminating lamp of claim 1 driving power, it is characterized in that: described control (IC1) is the PFM control integrated circuit.

4. according to the described LED illuminating lamp of claim 1 driving power, it is characterized in that: described control (IC1) is the self-oscillation control circuit.

5. according to the described LED illuminating lamp of claim 1 driving power, it is characterized in that: described transformer (T1) is that single transformer or a plurality of transformer are connected or a plurality of inductance is connected with single transformer.

6. according to the described LED illuminating lamp of claim 1 driving power, it is characterized in that: be connected to rectifying and wave-filtering electric capacity (C1) between two outputs of described rectification circuit, rectifying and wave-filtering electric capacity (C1) is metallized film capacitor or electrochemical capacitor.

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