CN211128328U

CN211128328U - Linear constant-current power supply with wide input voltage and high conversion efficiency

Info

Publication number: CN211128328U
Application number: CN201922125537.1U
Authority: CN
Inventors: 李学军; 雷云波; 李志科
Original assignee: Shenzhen Watt Zhihui Technology Co ltd
Current assignee: Guangdong industrial wing network technology Co.,Ltd.
Priority date: 2019-12-02
Filing date: 2019-12-02
Publication date: 2020-07-28
Anticipated expiration: 2029-12-02

Abstract

The utility model discloses a linear constant current power supply of wide input voltage high conversion efficiency, this linear constant current power supply of wide input voltage high conversion efficiency, including alternating current source AC, fuse F1, rectifier bridge BR1, linear power control IC, diode D1, mechanical switch S1, mechanical switch S2, sampling resistance Rcs, field effect transistor Q1 and n L ED. the beneficial effects of the utility model are that through the mode that changes the series-parallel number of L ED lamp according to the height of input voltage Vin in the linear constant current power supply, can let linear power supply use at wide range input voltage, safe and reliable can also realize high conversion efficiency when adapting to wide range input voltage, need not be equipped with a large amount of stocks, reduce cost pressure.

Description

Linear constant-current power supply with wide input voltage and high conversion efficiency

Technical Field

The utility model relates to an L ED power technical field particularly, relates to a linear constant current power supply of wide input voltage high conversion efficiency.

Background

In the design of a low-power L ED constant current power supply, in order to save cost, the high-voltage linear constant current power supply is more and more concerned by L ED enterprises because of the advantages of simple circuit, no EMI interference, high PF, high efficiency and the like, at present, the high-voltage linear constant current drives high-voltage lamp beads in a segmented lighting mode, the more segments are used, the higher the efficiency is, the more segments are used, the more circuits are used, the more segments are used, the more circuits are complex, and the large-scale production is not facilitated, the common most segments on the market are 3-4 segments, the working principle of the high-voltage linear constant:

at time t0-t1, the input voltage rises from 0, and since the input voltage is smaller than the turn-on value Vled of the whole string L ED lamp bead, at this time L ED is not bright, the current IF flowing through L ED is 0 in this time.

At the time of t1-t3, the input voltage continues to climb first and then descends, the input voltage is higher than the turn-on value Vled of the whole L ED lamp bead string in the time period, current flows through the L ED lamp bead, L ED 1-L EDn is lightened, the current flowing through the L ED lamp bead is sampled and fed back to the control IC through the sampling resistor Rcs, the IC detects the input voltage through the VS pin, and the internal constant current circuit controls the L ED current according to the input voltage signal and the current sampling signal to achieve constant current.

At time t3-t4, since the input voltage is less than the turn-on value Vled of the whole string L ED lamp bead, L ED is not bright, so the current IF flowing through L ED during this time is also 0.

The Q1 is linearly on for the entire time period t1-t3, so that the current IF flowing through L ED smoothly follows the input voltage, and therefore a higher PF value and a lower thdi can be achieved, the difference between the input voltage Vin and the on-value Vled of the entire string L ED lamp bead is also regulated by Q1, this difference is dissipated in the form of thermal energy on Q1, the greater the difference, the greater the loss of Q1, the lower the efficiency.

However, the mains voltage of different countries is different, for example, the mains voltage of China is 220Vac, and the mains voltage of Japan is 110Vac, in order to meet the market demand, the current solution of L ED manufacturers is that different input voltages are matched with L ED lamps with different strings.

This solution has the following disadvantages:

the first disadvantage is that: a large amount of stock is needed, and the cost and the pressure are high.

The second disadvantage is that: if the use condition of the customer is wrong, the risk of burning out the lamp beads and the IC exists, and the use condition is dangerous.

An effective solution to the problems in the related art has not been proposed yet.

SUMMERY OF THE UTILITY MODEL

To the problem among the correlation technique, the utility model provides a linear constant current power supply of wide input voltage high conversion efficiency to overcome the above-mentioned technical problem that current correlation technique exists.

Therefore, the utility model discloses a specific technical scheme as follows:

according to the utility model discloses an aspect provides a linear constant current power supply of wide input voltage high conversion efficiency.

The linear constant-current power supply with wide input voltage and high conversion efficiency comprises an alternating current source AC, a fuse F1, a rectifier bridge BR1, a linear power supply control IC, a diode D1, a mechanical switch S1, a mechanical switch S2, a sampling resistor Rcs, a field-effect tube Q1 and n L EDs;

two ends of the alternating current source AC are respectively connected with one end of the fuse F1 and a third end of the rectifier bridge BR1, the other end of the fuse F1 and a first end of the rectifier bridge BR1 are respectively connected, a second end of the rectifier bridge BR1 is sequentially connected with a VS pin, a L ED1 and one end of the mechanical switch S1 on the linear power supply control IC, the other end of the mechanical switch S1 is sequentially connected with a L ED (n/2) +1 and a negative electrode of the diode D1, an anode of the diode D1 is sequentially connected with one end of the mechanical switch S2 and a L EDn/2, the other end of the mechanical switch S2 is sequentially connected with a drain of the field effect transistor Q1 and an L EDn, n/2 ED1 and the drain of the L EDn/2 of the field effect transistor Q1 are sequentially connected in series, and n/2 ED1 and L ED (n/2) +1 and the source of the sampling resistor Rcs 1 on the linear power supply control IC are sequentially connected with a source of the sampling transistor Q1 and a sampling resistor on the sampling IC 1.

Preferably, the mechanical switch S1 and the mechanical switch S2 are both single-control type switches or multi-control type switches.

Preferably, the field effect transistor Q1 is an N-type MOSFET field effect transistor.

According to the utility model discloses a linear constant current power supply of wide input voltage high conversion efficiency is provided in another aspect.

The linear constant-current power supply with wide input voltage and high conversion efficiency comprises an alternating current source AC, a fuse F1, a rectifier bridge BR1, a linear power supply control IC, a diode D1, an electronic switch S1, an electronic switch S2, a sampling resistor Rcs, a field-effect tube Q1 and n L EDs;

two ends of the AC current source AC are connected to one end of the fuse F1 and the third end of the rectifier bridge BR1, the other end of the fuse F1 and the first end of the rectifier bridge BR1 are connected to the second end of the rectifier bridge BR1, which is connected to the VS pin, L ED1 and the drain of the electronic switch S1 on the linear power control IC in turn, the source of the electronic switch S1 is connected to the first isolation driving pin, L ED (n/2) +1 and the negative electrode of the diode D1 on the linear power control IC in turn, the first isolation driving pin on the linear power control IC is connected to the gate of the electronic switch S1, the positive electrode of the diode D1 is connected to the drain of the electronic switch S2 and the drain of the electronic switch EDn/2 in turn, the source of the electronic switch S2 is connected to the second isolation driving pin, the drain of the fet Q1 and the L n on the linear power control IC in turn, the source of the second isolation driving pin on the linear power control IC is connected to the gate of the linear power control IC 2, and the sampling resistor r 2 and the sampling resistor 2 are connected to the gate 2 and the sampling resistor 2/2 on the sampling IC 2 and the sampling diode 2 (2).

Preferably, the electronic switch S1 and the electronic switch S2 are each a thyristor, a transistor, a field effect transistor, a thyristor, or a relay.

The utility model has the advantages of through the mode that changes L ED lamp's series-parallel number according to the height of input voltage Vin in the linear constant current power supply, can let the linear power supply use at wide range input voltage, safe and reliable can also realize high conversion efficiency when adapting to wide range input voltage, need not be equipped with a large amount of stocks, reduce cost pressure.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a circuit diagram of a linear constant current power supply with wide input voltage and high conversion efficiency according to a first embodiment of the present invention;

fig. 2 is a circuit diagram of a linear constant current power supply with wide input voltage and high conversion efficiency according to a second embodiment of the present invention;

fig. 3 is a circuit diagram of a constant current power supply in the related art.

Detailed Description

For further explanation of the embodiments, the drawings are provided as part of the disclosure and serve primarily to illustrate the embodiments and, together with the description, to explain the principles of operation of the embodiments, and to provide further explanation of the invention and advantages thereof, it will be understood by those skilled in the art that various other embodiments and advantages of the invention are possible, and that elements in the drawings are not to scale and that like reference numerals are generally used to designate like elements.

According to the utility model discloses an embodiment provides a linear constant current power supply of wide input voltage high conversion efficiency, and it is right now to combine figure and detailed implementation mode the utility model discloses explain further.

Example one

As shown in fig. 1, the linear constant current power supply with wide input voltage and high conversion efficiency according to the embodiment of the present invention includes an AC current source AC, a fuse F1, a rectifier bridge BR1, a linear power control IC, a diode D1, a mechanical switch S1, a mechanical switch S2, a sampling resistor Rcs, a field effect transistor Q1, and n L EDs;

In one embodiment, the mechanical switch S1 and the mechanical switch S2 are both single-control type switches or multi-control type switches.

In one embodiment, the fet Q1 is an N-type MOSFET fet.

Example two

As shown in fig. 2, the linear constant current power supply with wide input voltage and high conversion efficiency according to the embodiment of the present invention includes an AC current source AC, a fuse F1, a rectifier bridge BR1, a linear power control IC, a diode D1, an electronic switch S1, an electronic switch S2, a sampling resistor Rcs, a field effect transistor Q1, and n L EDs;

In one embodiment, the electronic switch S1 and the electronic switch S2 are each a thyristor, a transistor, a fet, a thyristor, or a relay.

In one embodiment, the fet Q1 is an N-type MOSFET fet.

For the convenience of understanding the technical solution of the present invention, the following detailed description is made on the working principle or the operation mode of the present invention in the practical process.

In practical application, in design, the number of strings of L ED lamp beads is matched according to 230Vac input voltage, L ED 1-L EDn-shared L ED lamp beads are matched in fig. 1, a VS pin of a control IC detects input voltage Vin, a threshold voltage Vvs can be set at the VS pin, the input voltage Vin is considered as high-voltage input when the voltage of the VS pin is detected to be greater than Vvs, the input voltage Vin is considered as low-voltage input when the voltage of the VS pin is detected to be less than Vvs, switches S1 and S2 are disconnected when the high-voltage input is detected, L2 ED 1-L EDn/2 and L EDn/2+ 1-L EDn are connected in series through a diode D1, the voltage Vled of the L ED lamp beads is close to the input voltage, high conversion efficiency can be achieved, the input voltage Vin is considered as low-voltage input when the voltage of the VS pin is detected to be less than Vvs, the switches S1 and S2 are closed simultaneously, the diode D5 can prevent the voltage of the EDn and the EDn/21 and the EDn +1 and S6862 from being connected in parallel, and the EDn/24 EDn-592 lamp string can be connected in parallel, and the EDn-592 lamp string with the EDn-L.

In one embodiment (i.e., in fig. 1), the switches S1 and S2 are mechanical switches that are mechanically operated to open and close the circuit and switch the circuit over and over, such as toggle switches for household light bulbs, including single-control type switches and multi-control type switches, and fig. 1 is a structure that uses a single-hole mechanical switch to change the number of series and parallel connections of a L ED lamp.

In the second embodiment (i.e., in fig. 2), the switches S1 and S2 are electronic switches, and the electronic switches are units that electronically drive a certain element through current or voltage to make and break a circuit, and include at least one controllable electronic driving device, such as a Thyristor (Thyristor), a Transistor (Transistor), a Field Effect Transistor (Field Effect Transistor), a Silicon Controlled Rectifier (Silicon Controlled Rectifier), a Relay (Relay), and the like, as shown in fig. 2, and have a structure that changes the serial-parallel number of L ED lamps by using an N-type MOSFET as a switch.

According to the requirements of practical application, the lamp beads can be expanded into a multi-path series-parallel mode, wherein multiple paths are connected in series when high voltage is input, and multiple paths are connected in parallel when low voltage is input.

In conclusion, with the aid of the technical scheme of the utility model, through the mode that changes L ED lamp's series-parallel number according to the height of input voltage Vin in the linear constant current power supply, can let the linear power supply use at wide range input voltage, safe and reliable can also realize high conversion efficiency when adapting to wide range input voltage, need not be equipped with a large amount of stocks, reduce cost pressure.

The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A linear constant current power supply with wide input voltage and high conversion efficiency is characterized by comprising an alternating current source AC, a fuse F1, a rectifier bridge BR1, a linear power supply control IC, a diode D1, a mechanical switch S1, a mechanical switch S2, a sampling resistor Rcs, a field effect transistor Q1 and n L EDs;

2. The linear constant-current power supply with wide input voltage and high conversion efficiency as claimed in claim 1, wherein the mechanical switch S1 and the mechanical switch S2 are both single-control type switches or multi-control type switches.

3. The linear constant-current power supply with wide input voltage and high conversion efficiency as claimed in claim 1, wherein the field effect transistor Q1 is an N-type MOSFET field effect transistor.

4. A linear constant current power supply with wide input voltage and high conversion efficiency is characterized by comprising an alternating current source AC, a fuse F1, a rectifier bridge BR1, a linear power supply control IC, a diode D1, an electronic switch S1, an electronic switch S2, a sampling resistor Rcs, a field effect transistor Q1 and n L EDs;

5. The linear constant-current power supply with wide input voltage and high conversion efficiency as claimed in claim 4, wherein the electronic switch S1 and the electronic switch S2 are each a thyristor, a transistor, a field effect transistor, a thyristor or a relay.

6. The linear constant-current power supply with wide input voltage and high conversion efficiency as claimed in claim 4, wherein the field effect transistor Q1 is an N-type MOSFET field effect transistor.