CN218183563U - Linear constant current drive circuit - Google Patents

Abstract

A linear constant current driving circuit comprises an input end, a rectifying circuit, a booster circuit, a plurality of lamp beads and a linear constant current circuit; the input end is connected with the rectifying circuit, the rectifying circuit is connected with the boosting circuit, the boosting circuit is connected with a plurality of lamp beads in series, the lamp beads are connected with the linear constant current circuit, the boosting value of the boosting circuit is matched with the number of the lamp beads in series, and the boosting circuit is an APFC boosting circuit; still include the MOS pipe, the grid of MOS pipe with linear constant current circuit connects, the source electrode pass through resistance R1 with boost circuit connects, the drain electrode pass through resistance R2 with the lamp pearl is connected, this application beneficial effect is: the application breaks through the conventional mode, and has the advantages of high PF value, low harmonic, high efficiency and no stroboflash through improvement.

Description

Linear constant current driving circuit

Technical Field

The utility model relates to a LED illumination field especially relates to a linear constant current drive circuit.

Background

With the continuous development and update of semiconductor technology, the current LED lighting driving power supply generally uses a switching power supply and a linear power supply, and in a low power product, a linear constant current IC is mainly used.

At present, a linear constant-current driving scheme is generally used in a mode that after rectification and filtering, the linear constant-current driving scheme is directly connected in series with the positive end or the negative end of a lamp bead, and after alternating-current voltage passes through rectification and filtering, a linear constant-current IC is directly connected in series with a circuit of the lamp bead. There are the following disadvantages:

1. after rectification and filtration, although an electrolytic capacitor is added, ripple voltage still exists, and the ripple voltage can be reduced by increasing the electrolytic capacitor, but the ripple voltage is not economical. Because the power frequency ripple waves are in the power frequency ripple waves, stroboscopic effect can be caused;

2. the power is unstable, the increase or decrease of the input voltage can cause the loss on the IC to increase or decrease, and the power fluctuates along with the fluctuation of the input voltage;

3. the lower the efficiency, the greater the differential pressure across the IC, the higher the losses and the lower the efficiency.

SUMMERY OF THE UTILITY MODEL

In order to solve the above problems, the present technical solution provides a linear constant current driving circuit.

In order to achieve the purpose, the technical scheme is as follows:

a linear constant current driving circuit comprises an input end, a rectifying circuit, a booster circuit, a plurality of lamp beads and a linear constant current circuit;

the input end is connected with the rectifying circuit, the rectifying circuit is connected with the boosting circuit, the boosting circuit is connected with the plurality of lamp beads in series, and the lamp beads are connected with the linear constant current circuit.

In some embodiments, the boost value of the boost circuit is matched with the number of the series-connected lamp beads.

In some embodiments, the boost circuit is an APFC boost circuit;

the grid electrode of the MOS tube is connected with the linear constant current circuit, the source electrode of the MOS tube is connected with the booster circuit through a resistor R1, and the drain electrode of the MOS tube is connected with the linear constant current circuit through a resistor R2.

The beneficial effect of this application does:

the application breaks through the conventional mode, and has the advantages of high PF value, low harmonic, high efficiency and no stroboflash through improvement.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly described below.

FIG. 1 is a first schematic structural diagram of an embodiment of the present invention;

fig. 2 is a schematic structural diagram ii of an embodiment of the present invention.

Detailed Description

In order to make the technical problem, technical solution and advantageous effects solved by the present invention more clearly understood, the following description is given in conjunction with the accompanying drawings and embodiments to further explain the present invention in detail. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Please refer to fig. 1-2;

the embodiment I provides a linear constant current driving circuit, which comprises an input end, a rectifying circuit, a booster circuit, a plurality of lamp beads and a linear constant current circuit;

the input end is connected with the rectifying circuit, the rectifying circuit is connected with the boosting circuit, the boosting circuit is connected with a plurality of lamp beads in series, the lamp beads are connected with the linear constant current circuit, and the boosting value of the boosting circuit is matched with the series quantity of the lamp beads.

As shown in fig. 1, after the rectifying circuit, a boost circuit is added to boost the rectified dc voltage to a fixed voltage value, for example, 400V, then the number of LEDs is calculated, and the voltage drop of the LEDs is calculated to be close to 400V, just as the linear IC enters a constant current state, at this time, the voltage drop on the linear constant current IC is minimum, the loss is minimum, and therefore, the efficiency is high.

The application breaks through a conventional using method, a filter circuit module is omitted, the voltage is boosted to about 400V through the BOOST after the filter circuit module is isomorphic rectifier bridge, then the lamp beads and the linear constant-current IC are connected in series, the voltage is boosted to about 400V through the BOOST voltage boosting circuit after the rectifier bridge is completed, the number of the lamp beads is determined according to the resistance value of the lamp beads, and the voltage drop of the LED is close to 400V, so that the linear IC enters a constant-current state.

In a second embodiment, the difference from the first embodiment is that the boosting circuit is an APFC boosting circuit;

the grid electrode of the MOS tube is connected with the linear constant current circuit, the source electrode of the MOS tube is connected with the booster circuit through a resistor R1, and the drain electrode of the MOS tube is connected with the linear constant current circuit through a resistor R2.

In the second embodiment, the BOOST circuit is replaced by a BOOST circuit with active APFC correction, the linear constant current of the later stage can be externally connected with MOS current expansion, and the power is increased. Or a plurality of ICs are used in parallel to increase power, and the circuit has the advantages that: high PF value, low harmonic, high efficiency and no stroboflash.

The above description is only a preferred embodiment of the present application and is not intended to limit the scope of the present application, and other embodiments and basic structures that are the same as or similar to the present application are within the scope of the present application.

Claims (3)

1. A linear constant current driving circuit is characterized by comprising an input end, a rectifying circuit, a booster circuit, a plurality of lamp beads and a linear constant current circuit;

the input end is connected with the rectifying circuit, the rectifying circuit is connected with the boosting circuit, the boosting circuit is connected with the plurality of lamp beads in series, and the lamp beads are connected with the linear constant current circuit.

2. The linear constant current drive circuit according to claim 1, wherein: the boosting value of the boosting circuit is matched with the number of the lamp beads connected in series.

3. The linear constant current drive circuit according to claim 1, wherein: the booster circuit is an APFC booster circuit;

the grid electrode of the MOS tube is connected with the linear constant current circuit, the source electrode of the MOS tube is connected with the booster circuit through a resistor R1, and the drain electrode of the MOS tube is connected with the linear constant current circuit through a resistor R2.

Images