Constant-current light-emitting device and LED lamp

Abstract

The utility model discloses a constant current light-emitting device and an LED lamp, and relates to the LED driving control technology, the constant current light-emitting device comprises a Schottky diode, the anode of the Schottky diode is connected with the output positive end of a power supply and the first end of a current-limiting resistor, and the cathode of the Schottky diode is connected with the first end of a control module and the control end of a power supply switch; the second end of the control module is grounded, and the control module is used for conducting the first end and the second end of the control module so as to control the power supply switch to be conducted; a current limiting resistor; the second end of the power supply switch is connected with the anode of the light-emitting diode, and the power supply switch is used for conducting the first end and the second end of the power supply switch so as to supply power to the light-emitting diode; and the cathode of the light-emitting diode is grounded, and the light-emitting diode is used for emitting light when being electrified. The Schottky diode adjusts the conduction voltage drop of the Schottky diode according to the temperature, and through the change of the divided voltage of the Schottky diode, the current flowing through the Schottky diode is constant along with the change of the environment temperature, namely constant-current light emitting is achieved.

Description

Technical Field

[0001] This utility model relates to the field of LED driving control, and in particular to a constant current light-emitting device and an LED lamp. Background Technology

[0002] Currently, many LED (Light-Emitting Diode) driver circuits require a constant current flow through the LED to achieve stable brightness, typically using integrated driver chips for constant current driving. Simultaneously, to prevent temperature-related brightness fluctuations, temperature sensors and control modules are also integrated. The temperature sensor feeds back the LED's temperature to the control module, which then adjusts the brightness, making the process complex. Utility Model Content

[0003] The purpose of this invention is to provide a constant current light-emitting device and an LED lamp, which achieves constant current light emission by changing the voltage divider of the Schottky diode and keeping the current flowing through it constant as the temperature of the light-emitting diode changes.

[0004] To solve the above-mentioned technical problems, this utility model provides a constant current light-emitting device, comprising:

[0005] The Schottky diode has its anode connected to the positive output terminal of the power supply and the first terminal of the current-limiting resistor, and its cathode connected to the first terminal of the control module and the control terminal of the power supply switch, for adjusting its on-state voltage drop according to temperature.

[0006] The control module has a second terminal grounded, which is used to connect its first terminal and second terminal to control the power supply switch to be turned on.

[0007] The current-limiting resistor, with its second end connected to the first end of the power supply switch, is used for current limiting.

[0008] The power supply switch has its second terminal connected to the anode of the light-emitting diode, and is used to conduct its first terminal to its second terminal to supply power to the light-emitting diode.

[0009] The light-emitting diode, with its cathode grounded, is used to emit light when energized.

[0010] On the other hand, it also includes protective resistors;

[0011] The first end of the protection resistor is connected to the anode of the light-emitting diode, and the second end is connected to the cathode of the light-emitting diode.

[0012] The protective resistor is used to discharge the reverse transient current of the light-emitting diode.

[0013] On the other hand, it also includes filter capacitors;

[0014] The first end of the filter capacitor is connected to the anode of the light-emitting diode, and the second end is connected to the cathode of the light-emitting diode.

[0015] The filter capacitor is used to filter the high-frequency interference generated by the light-emitting diode.

[0016] On the other hand, it also includes the first voltage divider resistor;

[0017] The first end of the first voltage divider resistor is connected to the positive output terminal of the power supply, and the second end of the first voltage divider resistor is connected to the anode of the Schottky diode for voltage division.

[0018] On the other hand, the power supply switch is a PNP transistor, with the base of the PNP transistor serving as the control terminal of the power supply switch, the emitter serving as the first terminal of the power supply switch, and the collector serving as the second terminal of the power supply switch.

[0019] On the other hand, when the light-emitting diode has a certain setting, the control module includes a second voltage divider resistor, a bias resistor, and a control switch;

[0020] The first end of the second voltage divider resistor is connected to the cathode of the Schottky diode, the second end of the second voltage divider resistor is connected to the first end of the control switch, the first end of the bias resistor is connected to the control signal, the second end of the bias resistor is connected to the control terminal of the control switch, and the second end of the control switch is grounded.

[0021] The control switch is used to turn on based on the control signal, so as to drive the power supply switch to turn on.

[0022] On the other hand, the control module also includes a bleed resistor;

[0023] The first end of the bleeder resistor is connected to the control terminal of the control switch, and the second end of the bleeder resistor is grounded. The bleeder resistor is used to bleed current.

[0024] On the other hand, the control switch is an NPN transistor, with the base of the NPN transistor serving as the control terminal of the control switch, the collector serving as the first terminal of the control switch, and the emitter serving as the second terminal of the control switch.

[0025] On the other hand, when the light-emitting diode has multiple settings, the control module includes multiple switching adjustment resistors and brightness adjustment switches, and the number of switching adjustment resistors is the same as the number of brightness adjustment switches and they correspond one-to-one.

[0026] The first end of the switch adjustment resistor is connected to the cathode of the Schottky diode, the second end of the switch adjustment resistor is connected to the first end of the brightness adjustment switch, and the second end of the brightness adjustment switch is grounded.

[0027] The brightness adjustment switch is used to connect its first terminal to its second terminal so that the corresponding switch adjustment resistor can be connected.

[0028] To solve the above-mentioned technical problems, this utility model also provides an LED lamp, including the aforementioned constant current light-emitting device.

[0029] This application provides a constant current light-emitting device and an LED lamp, relating to LED driving control technology. The device includes a Schottky diode, whose anode is connected to the positive output terminal of a power supply and the first terminal of a current-limiting resistor, and whose cathode is connected to the first terminal of a control module and the control terminal of a power supply switch. The control module has a second terminal grounded, used to conduct its first and second terminals to control the power supply switch. A current-limiting resistor is also included. A power supply switch has its second terminal connected to the anode of the LED, used to conduct its first and second terminals to power the LED. The LED's cathode is grounded, used to emit light when powered. The Schottky diode adjusts its forward voltage drop according to temperature. By changing the voltage division of the Schottky diode, the current flowing through it remains constant despite changes in ambient temperature, i.e., constant current light emission. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the prior art and embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 A schematic diagram of the structure of a constant current light-emitting device provided by this utility model;

[0032] Figure 2 A schematic diagram of the structure of a constant current light-emitting device with one gear position provided by this utility model;

[0033] Figure 3 This is a schematic diagram of the structure of a constant current light-emitting device with multiple levels provided by this utility model. Detailed Implementation

[0034] The core of this invention is to provide a constant current light-emitting device and an LED lamp. By changing the voltage division of a Schottky diode, the current flowing through the LED remains constant as the temperature of the LED changes, thus achieving constant current light emission.

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0036] Figure 1 This is a schematic diagram of a constant current light-emitting device provided by the present invention. The constant current light-emitting device includes:

[0037] Schottky diode D1 has its anode connected to the positive output terminal of the power supply and the first terminal of the current limiting resistor R1, and its cathode connected to the first terminal of the control module 1 and the control terminal of the power supply switch T1. It is used to adjust its own on-state voltage drop according to the temperature of the light-emitting diode D2.

[0038] Control module 1, with its second terminal grounded, is used to connect its first and second terminals to control the power supply switch T1 to turn on.

[0039] A current-limiting resistor R1 is connected at its second end to the first end of the power supply switch T1 for current limiting.

[0040] Power supply switch T1, the second terminal of power supply switch T1 is connected to the anode of light-emitting diode D2, and is used to conduct its first terminal and second terminal to supply power to light-emitting diode D2;

[0041] LED D2, with its cathode grounded, is used to emit light when energized.

[0042] Currently, many LED (Light-Emitting Diode) driver circuits require a constant current flow through the LED to achieve stable brightness, typically using integrated driver chips for constant current driving. Simultaneously, to prevent temperature-related fluctuations in LED brightness, a temperature sensor and control module 1 are also integrated. The temperature sensor feeds back the LED's temperature to the control module 1, which then handles heat dissipation, making the process complex.

[0043] According to the calculation formula I D2 =(V CC -((V CC -V D1 )*R x / (R y +R x )+V BE)) / R1, where V CC I is the voltage of the power supply. D2 V is the current flowing through the light-emitting diode D2. D1 It is the forward voltage of the Schottky diode D1, V BE It is the emitter junction voltage drop of power supply switch T1, R x To control the resistance of module 1, R y R is the resistance value of the first voltage divider resistor. x / (R y +R x The voltage divider relationship is shown, and R1 is the resistance value of the current-limiting resistor. (V) BE It is a quantity that changes with temperature; as the temperature rises, V... BE A voltage drop, for example within a temperature range of -40℃ to 85℃, can result in a voltage deviation of approximately 0.5V. This will cause a deviation in the current of the LED D2, making it impossible to maintain a constant current. This is because the forward voltage of the Schottky diode D1 decreases as temperature increases. According to the formula above, within a wide temperature range, as long as appropriate components are selected based on the actual circuit conditions, the LED current can be kept essentially constant.

[0044] A current-limiting resistor R1 is set to prevent excessive current flowing through LED D2, which could damage LED D2 and power switch T1.

[0045] The control module 1 can be controlled by a button pressed manually by the user or by other forms of switches. This application does not impose any restrictions here. The control module 1 only needs to connect its first and second terminals when it needs to control the LED D2 to emit light. When the first and second terminals of the control module 1 are connected, the power supply switch T1 drives its own conduction based on the control terminal, thereby energizing the LED D2 and causing it to emit light.

[0046] This application provides a constant current light-emitting device, relating to LED driving control technology, including a Schottky diode D1. The anode of Schottky diode D1 is connected to the positive output terminal of a power supply and the first terminal of a current-limiting resistor R1. The cathode of Schottky diode D1 is connected to the first terminal of a control module 1 and the control terminal of a power supply switch T1. The control module 1 has its second terminal grounded, used to conduct its first and second terminals to control the power supply switch T1 to conduct. The current-limiting resistor R1 is also included. The power supply switch T1 has its second terminal connected to the anode of a light-emitting diode D2, used to conduct its first and second terminals to supply power to the light-emitting diode D2. The cathode of the light-emitting diode D2 is grounded, used to emit light when powered. Schottky diode D1 adjusts its forward voltage drop according to the ambient temperature. By changing the voltage drop across Schottky diode D1, the current flowing through it remains constant despite changes in the temperature of the light-emitting diode D2, i.e., constant current light emission.

[0047] Based on the above embodiments:

[0048] In some embodiments, a protective resistor R2 is also included;

[0049] The first end of the protection resistor R2 is connected to the anode of the light-emitting diode D2, and the second end is connected to the cathode of the light-emitting diode D2.

[0050] The protective resistor R2 is used to discharge the reverse transient current of the light-emitting diode D2.

[0051] A protective resistor R2 is connected in parallel across the LED D2 to provide a discharge path when a reverse transient current occurs in the LED D2, preventing damage or unstable brightness. The protective resistor R2 is typically a large value resistor, which reduces the shunt effect on the LED D2 and provides better protection.

[0052] In some embodiments, a filter capacitor C1 is also included;

[0053] The first terminal of the filter capacitor C1 is connected to the anode of the light-emitting diode D2, and the second terminal is connected to the cathode of the light-emitting diode D2.

[0054] The filter capacitor C1 is used to filter the high-frequency interference generated by the light-emitting diode D2.

[0055] The parallel filter capacitor C1 of LED D2 can stabilize the voltage when the driving voltage of LED D2 is unstable and fluctuates, and can also filter high-frequency interference to prevent brightness fluctuations of LED D2.

[0056] In some embodiments, a first voltage divider resistor R3 is also included;

[0057] The first end of the first voltage divider resistor R3 is connected to the positive output terminal of the power supply, and the second end of the first voltage divider resistor R3 is connected to the anode of the Schottky diode D1 for voltage division.

[0058] The first voltage divider resistor R3 is connected between the base of the transistor and the power supply to prevent the base from floating and avoid malfunctions caused by noise signals. It provides bias voltage to ensure the transistor operates in amplification mode. In switching circuits, it aids in charging and discharging, improving switching speed. It also protects the transistor from damage caused by excessive current.

[0059] In some embodiments, the power supply switch T1 is a PNP transistor, with the base of the PNP transistor serving as the control terminal of the power supply switch T1, the emitter serving as the first terminal of the power supply switch T1, and the collector serving as the second terminal of the power supply switch T1.

[0060] For a PNP transistor to conduct, the following two conditions must be met simultaneously:

[0061] Forward bias of the emitter junction: Base (B) voltage > Emitter (E) voltage, i.e., VBE > 0.7V (approximately 0.2V for silicon transistors and germanium transistors). At this time, the emitter junction (BE junction) is turned on, allowing holes to flow from the emitter to the base.

[0062] Reverse bias of the collector junction: collector (C) voltage < emitter (E) voltage, i.e., VCE > 0. At this time, the collector junction (BC junction) is reverse biased, preventing majority carriers (electrons) from flowing from the collector to the base, while allowing holes that diffuse from the emitter to the base to be collected by the collector.

[0063] Figure 2 A schematic diagram of the structure of a constant current light-emitting device with one gear position provided by this utility model;

[0064] In some embodiments, when the light-emitting diode D2 has a position, the control module 1 includes a second voltage divider resistor R4, a bias resistor R5, and a control switch T2.

[0065] The first end of the second voltage divider resistor R4 is connected to the cathode of the Schottky diode D1, the second end of the second voltage divider resistor R4 is connected to the first end of the control switch T2, the first end of the bias resistor R5 is connected to the control signal, the second end of the bias resistor R5 is connected to the control terminal of the control switch T2, and the second end of the control switch T2 is grounded.

[0066] Control switch T2 is used to turn on based on a control signal so as to drive power supply switch T1 to turn on.

[0067] The control switch T2 is turned on and off based on the high or low level of the connected control signal PWM (Pulse Width Modulation). When the control switch T2 is turned on, the power supply switch T1 will be turned on, thereby supplying power to the light-emitting diode D2.

[0068] The bias resistor R5 is mainly used to provide a suitable bias voltage to the base of the transistor, ensuring that the transistor operates in amplification mode. It prevents input signal distortion and enables the transistor to amplify weak signals.

[0069] In some embodiments, the control module 1 further includes a bleed resistor R6;

[0070] The first end of the bleeder resistor R6 is connected to the control terminal of the control switch T2, and the second end of the bleeder resistor R6 is grounded. The bleeder resistor R6 is used to bleed current.

[0071] The bleeder resistor R6 provides a discharge path for the base charge when the input signal is disconnected, preventing residual charge from affecting the transistor's state. It also prevents the base from floating, thus avoiding malfunctions caused by noise signals.

[0072] In some embodiments, the control switch T2 is an NPN transistor, with the base of the NPN transistor serving as the control terminal of the control switch T2, the collector serving as the first terminal of the control switch T2, and the emitter serving as the second terminal of the control switch T2.

[0073] For an NPN transistor to conduct, the following two conditions must be met simultaneously:

[0074] Forward bias of the emitter junction: Base (B) voltage > Emitter (E) voltage, i.e., VBE > 0.7V (approximately 0.2V for silicon transistors and germanium transistors). At this time, the emitter junction (BE junction) is turned on, allowing electrons to flow from the emitter to the base.

[0075] Reverse bias of the collector junction: collector (C) voltage > base (B) voltage, i.e., VCB > 0. At this time, the collector junction (BC junction) is reverse biased, preventing majority carriers (holes) from flowing from the collector to the base, while allowing electrons diffused from the emitter to the base to be collected by the collector.

[0076] Figure 3 A schematic diagram of the structure of a constant current light-emitting device with multiple levels provided by this utility model;

[0077] In some embodiments, when the light-emitting diode D2 has multiple settings, the control module 1 includes multiple switching adjustment resistors and brightness adjustment switches, and the number of switching adjustment resistors is the same as the number of brightness adjustment switches and they correspond one-to-one.

[0078] The first terminal of the switching adjustment resistor is connected to the cathode of the Schottky diode D1, the second terminal of the switching adjustment resistor is connected to the first terminal of the brightness adjustment switch, and the second terminal of the brightness adjustment switch is grounded.

[0079] The brightness adjustment switch is used to connect its first terminal to its second terminal so that the corresponding switch adjustment resistor can be connected.

[0080] This application takes three levels as an example, with three switches adjusting resistors R7, R8 and R9, and three brightness adjustment switches S1, S2 and S3.

[0081] When the brightness is at level 1, the brightness adjustment switch S1 is closed. When it is necessary to switch to level 2 and level 3 brightness, it is only necessary to close the corresponding brightness adjustment switches S2 and S3. Based on this circuit, the LED D2 can be driven by constant current in multiple levels over a wide temperature range.

[0082] This application also provides an LED lamp, including the aforementioned constant current light-emitting device.

[0083] The description of the LED lights provided in this application is provided in the above embodiments and will not be repeated here.

[0084] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0085] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0086] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A constant current light emitting device, characterized by, The application relates to a power supply circuit for a light-emitting diode (LED), which comprises: a Schottky diode, an anode of the Schottky diode being connected with an output positive terminal of a power supply and a first terminal of a current-limiting resistor, a cathode of the Schottky diode being connected with a first terminal of a control module and a control terminal of a power supply switch, and the Schottky diode being used for adjusting a conduction voltage drop of itself according to temperature; the control module, a second terminal of the control module being grounded, and the control module being used for conducting the first terminal and the second terminal of itself to control the power supply switch to be conducted; the current-limiting resistor, a second terminal of the current-limiting resistor being connected with a first terminal of the power supply switch, and the current-limiting resistor being used for current limiting; the power supply switch, a second terminal of the power supply switch being connected with an anode of the LED, and the power supply switch being used for conducting the first terminal and the second terminal of itself to supply power for the LED; and the LED, a cathode of the LED being grounded, and the LED being used for emitting light when being electrified. The application further comprises a protection resistor, a first terminal of the protection resistor being connected with the anode of the LED, and a second terminal of the protection resistor being connected with the cathode of the LED; and the protection resistor being used for discharging reverse transient current of the LED. The application further comprises a filter capacitor, a first terminal of the filter capacitor being connected with the anode of the LED, and a second terminal of the filter capacitor being connected with the cathode of the LED; and the filter capacitor being used for filtering high-frequency interference generated by the LED. The application further comprises a first voltage-dividing resistor, a first terminal of the first voltage-dividing resistor being connected with the output positive terminal of the power supply, and a second terminal of the first voltage-dividing resistor being connected with the anode of the Schottky diode; and the first voltage-dividing resistor being used for voltage dividing. The power supply switch is a PNP triode, a base of the PNP triode being used as the control terminal of the power supply switch, an emitter of the PNP triode being used as the first terminal of the power supply switch, and a collector of the PNP triode being used as the second terminal of the power supply switch. When the LED has one gear, the control module comprises a second voltage-dividing resistor, a bias resistor and a control switch; a first terminal of the second voltage-dividing resistor being connected with the cathode of the Schottky diode, a second terminal of the second voltage-dividing resistor being connected with a first terminal of the control switch, a first terminal of the bias resistor being connected with a control signal, a second terminal of the bias resistor being connected with a control terminal of the control switch, and a second terminal of the control switch being grounded; and the control switch being used for being conducted based on the control signal to drive the power supply switch to be conducted.

2. The constant current light emitting device of claim 1, wherein, The control module further comprises a discharge resistor; a first terminal of the discharge resistor being connected with the control terminal of the control switch, and a second terminal of the discharge resistor being grounded; and the discharge resistor being used for discharging current. The control switch is an NPN triode, a base of the NPN triode being used as the control terminal of the control switch, a collector of the NPN triode being used as the first terminal of the control switch, and an emitter of the NPN triode being used as the second terminal of the control switch. When the LED has multiple gears, the control module comprises multiple switch adjusting resistors and a brightness adjusting switch; the number of the switch adjusting resistors is the same as and corresponds to the number of the brightness adjusting switch.

3. The constant current light emitting device of claim 1, wherein the first and second conductive layers are formed of a conductive material selected from the group consisting of gold, silver, copper, aluminum, and combinations thereof. ​ ​ ​ 4. The constant current light emitting device of claim 1, wherein the first and second conductive layers are formed of a conductive material selected from the group consisting of gold, silver, copper, aluminum, and combinations thereof. ​ ​ 5. The constant current light emitting device of claim 1, wherein the first and second conductive layers are formed of a conductive material selected from the group consisting of gold, silver, copper, aluminum, and combinations thereof. ​ 6. The constant current light emitting device according to any one of claims 1 to 5, wherein ​ ​ ​ 7. The constant current light emitting device of claim 6, wherein the first and second conductive layers are formed of a conductive material selected from the group consisting of gold, silver, copper, aluminum, and combinations thereof. ​ ​ 8. The constant current light emitting device of claim 6, wherein the first and second conductive layers are formed of a conductive material selected from the group consisting of gold, silver, copper, aluminum, and combinations thereof. ​ 9. The constant current light emitting device of any one of claims 1 to 5, wherein, ​ The first end of the switch adjustment resistor is connected with the cathode of the Schottky diode, the second end of the switch adjustment resistor is connected with the first end of the brightness adjustment switch, and the second end of the brightness adjustment switch is grounded. The brightness adjustment switch is used to connect the first end and the second end of the brightness adjustment switch, so as to connect the corresponding switch adjustment resistor.

10. An LED lamp, characterized by A constant current light emitting device comprising the constant current light emitting device according to any one of claims 1 to 9.

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