Current setting circuit of LED lamp capable of setting color temperature through multi-gear switch

Abstract

The utility model discloses a current setting circuit of an LED lamp for setting color temperature through a multi-gear switch, which is provided with a first end, a second end and a negative electrode, and comprises the multi-gear switch, a first triode, a second triode, a first resistor, a second resistor, a third resistor, a fourth resistor and a fifth resistor, the multi-gear switch is realized by adopting a two-path five-gear switch formed by linkage of two paths of one-out-five switches, and by utilizing a mirror image circuit principle, the proportion of current flowing through a first end and a second end of the multi-gear switch corresponds to the proportion of a resistance value between an emitting electrode of a first triode and a negative electrode of the first triode and a resistance value between an emitting electrode of a second triode and a negative electrode of the second triode; the influence of the working voltage of the high-color-temperature LED circuit and the low-color-temperature LED circuit along with the change of the working current and the temperature is avoided; the color temperature setting circuit has the advantages that the cost is low, and the color temperature of mixed light generated when the high-color-temperature LED circuit and the low-color-temperature LED circuit emit light at the same time can be accurately set.

Description

Technical Field

[0001] The utility model relates to a current setting circuit, in particular to a current setting circuit of an LED lamp with a multi - gear switch for setting color temperature. Background Art

[0002] As Figure 1 shown, the existing LED lamp circuit with a multi - gear switch for setting color temperature generally includes a constant - current driving circuit, a high - color - temperature LED circuit, a low - color - temperature LED circuit, and a current setting circuit. The constant - current driving circuit has a first input terminal, a second input terminal, a positive output terminal, and a negative output terminal. When its first input terminal and second input terminal are connected to the mains voltage, a direct - current current is output between its positive output terminal and negative output terminal. The high - color - temperature LED circuit has a positive electrode and a negative electrode, and emits high - color - temperature light when a direct - current current is connected between its positive electrode and negative electrode, and its luminous intensity is proportional to the magnitude of the direct - current current connected thereto. The low - color - temperature LED circuit has a positive electrode and a negative electrode, and emits low - color - temperature light when a direct - current current is connected between its positive electrode and negative electrode, and its luminous intensity is proportional to the magnitude of the direct - current current connected thereto. The current setting circuit has a first terminal, a second terminal, and a negative electrode, and includes a multi - gear switch. The multi - gear switch has multiple states. When the multi - gear switch is set in different states, the current ratio flowing through the first terminal and the second terminal of the current setting circuit is correspondingly set, that is, each state of the multi - gear switch corresponds to a ratio of the currents flowing through the first terminal and the second terminal of the current setting circuit. The first terminal of the current setting circuit is connected to the negative electrode of the high - color - temperature LED circuit, the second terminal of the current setting circuit is connected to the negative electrode of the low - color - temperature LED circuit, the positive electrodes of the high - color - temperature LED circuit, the low - color - temperature LED circuit, and the positive output terminal of the constant - current driving circuit are connected, and the negative electrode of the current setting circuit is connected to the negative output terminal of the constant - current driving circuit. When the mains voltage is connected between the first input terminal and the second input terminal of the constant - current driving circuit, a direct - current current is output between its positive output terminal and negative output terminal. At this time, the total current magnitude flowing through the first terminal and the second terminal of the current setting circuit is equal to the magnitude of the direct - current current output between the positive output terminal and the negative output terminal of the constant - current driving circuit, and the ratio of the current magnitudes flowing through the first terminal and the second terminal of the current setting circuit corresponds to the state of the multi - gear switch. The luminous intensities of the high - color - temperature LED circuit and the low - color - temperature LED circuit are also in corresponding proportion. In this way, the color temperature of the mixed light formed by the high - color - temperature light and the low - color - temperature light emitted by the LED lamp with a multi - gear switch for setting color temperature also has a corresponding relationship with the state of the multi - gear switch, that is, each state of the multi - gear switch corresponds to a mixed - light color temperature.

[0003] There are mainly two types of the existing current setting circuits of LED lamps with a multi - gear switch for setting color temperature. The first type of current setting circuit directly uses a two - resistor shunt method to set the ratio of the currents flowing through the high - color - temperature LED circuit and the low - color - temperature LED circuit (that is, the ratio of the currents flowing through its first terminal and second terminal). Its simplified circuit is as Figure 2As shown, the second current setting circuit uses a time-division conduction method to set the ratio of the currents flowing through the high-color-temperature LED circuit and the low-color-temperature LED circuit. Its simplified circuit is as Figure 3 shown.

[0004] In the above-mentioned first current setting circuit, the multi-position switch sets the resistance value of the resistor R1 between its first end and the negative electrode, and the resistance value of the resistor R2 between its second end and the negative electrode, and changes the resistance value ratio between the resistor R1 and the resistor R2, so as to be able to adjust the ratio of the current flowing between its first end and the second end in the current setting circuit. Although this current setting circuit has the advantage of low cost, in actual applications, since the operating voltages of the high-color-temperature LED circuit and the low-color-temperature LED circuit are easily affected by the magnitude of the operating current and temperature and will change with the magnitude of the operating current and temperature, the color temperature of the mixed light generated when the high-color-temperature LED circuit and the low-color-temperature LED circuit emit light simultaneously is very difficult to meet the requirements of the preset color temperature index.

[0005] In the above-mentioned second current setting circuit, the state set by the multi-position switch in the current setting circuit is converted into a PWM signal with a corresponding duty cycle, and the on and off of two MOS transistors Q1 and Q2 are controlled by this PWM signal, so that a periodic change of a complementary on and off state occurs between its first end and the second end and the negative electrode, that is, the high-color-temperature LED circuit and the low-color-temperature LED circuit are alternately connected to the current. At this time, the ratio of the average current magnitudes generated between its first end and the negative electrode and between the second end and the negative electrode corresponds to the duty cycle of the PWM signal. Although the ratio of the currents for driving the high-color-temperature LED circuit and driving the low-color-temperature LED generated by this current setting circuit is not affected by the changes in the operating voltages of the high-color-temperature LED circuit and the low-color-temperature LED circuit with the operating current and temperature, and can accurately set the color temperature of the mixed light generated when the high-color-temperature LED circuit and the low-color-temperature LED circuit emit light simultaneously, its cost is relatively high. Summary of the Invention

[0006] The technical problem to be solved by the present utility model is to provide a current setting circuit for an LED lamp with a multi-position switch for setting the color temperature, which can accurately set the color temperature of the mixed light generated when the high-color-temperature LED circuit and the low-color-temperature LED circuit emit light simultaneously while having a low cost.

[0007] The technical solution adopted by the present utility model to solve the above technical problems is as follows: An LED lamp current setting circuit with color temperature set by a multi-position switch, having a first terminal, a second terminal and a negative electrode, and including a multi-position switch. The multi-position switch is implemented by a two-way five-position switch formed by the linkage of two five-way one-select switches. Each five-way one-select switch has a first terminal, a second terminal, a third terminal, a fourth terminal, a fifth terminal and a common terminal. The two five-way one-select switches are respectively referred to as the first-way switch and the second-way switch. The multi-position switch has five states, and the five setting states are respectively referred to as the first state, the second state, the third state, the fourth state and the fifth state. In the first state, the common terminal of the first-way switch is only connected to its first terminal, and the common terminal of the second-way switch is only connected to its first terminal. In the second state, the common terminal of the first-way switch is only connected to its second terminal, and the common terminal of the second-way switch is only connected to its second terminal. In the third state, the common terminal of the first-way switch is only connected to its third terminal, and the common terminal of the second-way switch is only connected to its third terminal. In the fourth state, the common terminal of the first-way switch is only connected to its fourth terminal, and the common terminal of the second-way switch is only connected to its fourth terminal. In the fifth state, the common terminal of the first-way switch is only connected to its fifth terminal, and the common terminal of the second-way switch is only connected to its fifth terminal. The current setting circuit further includes a first triode, a second triode, a first resistor, a second resistor, a third resistor, a fourth resistor and a fifth resistor. The first terminal, the second terminal and the third terminal of the first-way switch, the first terminal of the second-way switch and the collector of the first triode are connected, and the connection end is the first terminal of the current setting circuit. The fourth terminal and the fifth terminal of the first-way switch, the fifth terminal of the second-way switch and the collector of the second triode are connected, and the connection end is the second terminal of the current setting circuit. The common terminal of the first-way switch is connected to one end of the first resistor. The other end of the first resistor, the base of the first triode and the base of the second triode are connected. The emitter of the first triode, one end of the second resistor and one end of the third resistor are connected. The other end of the second resistor is connected to the second terminal of the second-way switch. The emitter of the second triode, one end of the fourth resistor and one end of the fifth resistor are connected. The other end of the fifth resistor is connected to the fourth terminal of the second-way switch. The other end of the third resistor, the other end of the fourth resistor and the common terminal of the second-way switch are connected, and the connection end is the negative electrode of the current setting circuit. The resistance value of the third resistor is less than or equal to the resistance value of the fourth resistor, and the resistance value of the fifth resistor satisfies: when the fourth resistor and the fifth resistor are connected in parallel, their parallel resistance value is less than or equal to the resistance value of the third resistor.

[0008] Compared with the prior art, the advantages of the present utility model are as follows: a multi - gear switch is realized by adopting a two - way five - gear switch formed by the linkage of two five - to - one switches, and a first triode, a second triode, a first resistor, a second resistor, a third resistor, a fourth resistor and a fifth resistor are set. When the current flowing through the first end of the current setting circuit of the present utility model is greater than or equal to the current flowing through its second end, the bases of the first triode and the second triode are connected through the first resistor and the first end of the current setting circuit of the present utility model. When the current flowing through the first end of the current setting circuit of the present utility model is less than the current flowing through its second end, the bases of the first triode and the second triode are connected through the first resistor and the second end of the current setting circuit of the present utility model. Thus, the current setting circuit of the present utility model utilizes the principle of mirror circuit, so that the ratio of the currents flowing through its first end and second end corresponds to the ratio of the resistance value between the emitter of the first triode and its negative electrode and the resistance value between the emitter of the second triode and its negative electrode, and is not affected by the changes of the working voltages of the high - color - temperature LED circuit and the low - color - temperature LED circuit with the working current and temperature. Therefore, the ratio of the currents generated by the current setting circuit of the present utility model for driving the high - color - temperature LED circuit and driving the low - color - temperature LED is not affected by the working voltage deviation of the high - color - temperature LED circuit and the low - color - temperature LED circuit. The set current ratio has high precision, and can accurately set the color temperature of the mixed light generated when the high - color - temperature LED circuit and the low - color - temperature LED circuit emit light simultaneously. In addition, the current setting circuit of the present utility model is built with very low - cost discrete devices and has low cost. Description of the Drawings

[0009] Figure 1 is the structural block diagram of an LED lamp circuit with a multi - gear switch for setting color temperature in the prior art;

[0010] Figure 2 is the simplified diagram of the current setting circuit of the first type of LED lamp with a multi - gear switch for setting color temperature in the prior art;

[0011] Figure 3 is the simplified diagram of the current setting circuit of the second type of LED lamp with a multi - gear switch for setting color temperature in the prior art;

[0012] Figure 4 is the circuit diagram of the current setting circuit of the LED lamp with a multi - gear switch for setting color temperature of the present utility model. Detailed Description of the Embodiment

[0013] The present utility model will be further described in detail below in conjunction with the embodiments of the drawings.

[0014] Embodiment: As Figure 4As shown, a current setting circuit for an LED lamp with a multi - gear switch for setting color temperature has a first terminal, a second terminal, and a negative electrode, and includes a multi - gear switch. The multi - gear switch is implemented by a two - way five - gear switch formed by the linkage of two five - way one - select switches. Each five - way one - select switch has a first terminal, a second terminal, a third terminal, a fourth terminal, a fifth terminal, and a common terminal. The two five - way one - select switches are respectively called the first - way switch K1 and the second - way switch K2. The multi - gear switch has five states, which are respectively called the first state, the second state, the third state, the fourth state, and the fifth state. In the first state, the common terminal COM1 of the first - way switch K1 is only connected to its first terminal P1 - 1, and the common terminal COM2 of the second - way switch K2 is only connected to its first terminal P2 - 1. In the second state, the common terminal COM1 of the first - way switch K1 is only connected to its second terminal P1 - 2, and the common terminal COM2 of the second - way switch K2 is only connected to its second terminal P2 - 2. In the third state, the common terminal COM1 of the first - way switch K1 is only connected to its third terminal P1 - 3, and the common terminal COM2 of the second - way switch K2 is only connected to its third terminal P2 - 3. In the fourth state, the common terminal COM1 of the first - way switch K1 is only connected to its fourth terminal P1 - 4, and the common terminal COM2 of the second - way switch K2 is only connected to its fourth terminal P2 - 4. In the fifth state, the common terminal COM1 of the first - way switch K1 is only connected to its fifth terminal P1 - 5, and the common terminal COM2 of the second - way switch K2 is only connected to its fifth terminal P2 - 5;The current setting circuit further includes a first triode Q1, a second triode Q2, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, and a fifth resistor R5. The first terminal P1-1, the second terminal P1-2, and the third terminal P1-3 of the first switch K1, the first terminal P2-1 of the second switch K2, and the collector of the first triode Q1 are connected, and the connection terminal is the first terminal of the current setting circuit. The fourth terminal P1-4 and the fifth terminal P1-5 of the first switch K1, the fifth terminal P2-5 of the second switch K2, and the collector of the second triode Q2 are connected, and the connection terminal is the second terminal of the current setting circuit. The common terminal COM1 of the first switch K1 is connected to one end of the first resistor R1. The other end of the first resistor R1, the base of the first triode Q1, and the base of the second triode Q2 are connected. The emitter of the first triode Q1, one end of the second resistor R2, and one end of the third resistor R3 are connected. The other end of the second resistor R2 is connected to the second terminal P2-2 of the second switch K2. The emitter of the second triode Q2, one end of the fourth resistor R4, and one end of the fifth resistor R5 are connected. The other end of the fifth resistor R5 is connected to the fourth terminal P2-4 of the second switch K2. The other ends of the third resistor R3 and the fourth resistor R4 and the common terminal COM2 of the second switch K2 are connected, and the connection terminal is the negative pole of the current setting circuit. The resistance value of the third resistor R3 is less than or equal to the resistance value of the fourth resistor R4, and the resistance value of the fifth resistor R5 satisfies: when the fourth resistor R4 and the fifth resistor R5 are connected in parallel, their parallel resistance value is less than or equal to the resistance value of the third resistor R3.;

[0015] In the current setting circuit of the present utility model, when the current flowing through its first end is greater than or equal to the current flowing through its second end, the bases of the first triode Q1 and the second triode Q2 are connected to its first end through the first resistor R1. When the current flowing through its first end is less than the current flowing through its second end, the bases of the first triode Q1 and the second triode Q2 are connected to its second end through the first resistor R1. Thus, the current setting circuit of the present utility model utilizes the mirror circuit principle to make the ratio of the currents flowing through its first end and second end correspond to the ratio of the resistance value between the emitter of the first triode Q1 and its negative electrode and the resistance value between the emitter of the second triode Q2 and its negative electrode, and is independent of the operating voltages of the high-color-temperature LED circuit and the low-color-temperature LED circuit. Therefore, the ratio of the currents generated by the current setting circuit of the present utility model to drive the high-color-temperature LED circuit and the low-color-temperature LED is not affected by the changes in the operating voltages of the high-color-temperature LED circuit and the low-color-temperature LED circuit with the operating current and temperature. Compared with the first current setting circuit that directly uses two resistors for current shunting to set the ratio of the currents flowing through the high-color-temperature LED circuit and the low-color-temperature LED circuit, the set current ratio has high accuracy and can accurately set the color temperature of the mixed light generated when the high-color-temperature LED circuit and the low-color-temperature LED circuit emit light simultaneously. In addition, the current setting circuit of the present utility model is built with discrete devices with very low costs, such as a multi-stage switch implemented by a two-way five-stage switch formed by the linkage of two five-way switches, the first triode Q1, the second triode Q2, the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4, and the fifth resistor R5. Its cost is much lower than that of the second current setting circuit that uses the time-division conduction method to set the ratio of the currents flowing through the high-color-temperature LED circuit and the low-color-temperature LED circuit, and has low cost.

Claims

1. A current setting circuit for an LED lamp with a multi-speed switch for setting the color temperature, comprising a first terminal, a second terminal and a cathode, and comprising a multi-speed switch, characterized in that The multi-speed switch is realized by a two-way five-speed switch formed by the linkage of two five-way switches. Each five-way switch has a first end, a second end, a third end, a fourth end, a fifth end and a common end. The two five-way switches are respectively referred to as the first-way switch and the second-way switch. The multi-speed switch has five states, and the five setting states are respectively referred to as the first state, the second state, the third state, the fourth state and the fifth state. The first state is that the common end of the first-way switch is only connected to its first end, and the common end of the second-way switch is only connected to its first end. The second state is that the common end of the first-way switch is only connected to its second end, and the second-way switch The common end is only connected to the second end thereof, the third state is that the common end of the first switch is only connected to the third end thereof, and the common end of the second switch is only connected to the third end thereof, the fourth state is that the common end of the first switch is only connected to the fourth end thereof, and the common end of the second switch is only connected to the fourth end thereof, the fifth state is that the common end of the first switch is only connected to the fifth end thereof, and the common end of the second switch is only connected to the fifth end thereof; the current setting circuit further includes a first triode, a second triode, a first resistor, a second resistor, a third resistor, a fourth resistor and a fifth resistor, the first end of the first switch, the second triode, a first resistor, a second resistor, a third resistor, a fourth resistor and a fifth resistor, The first end and the third end, the first end of the second switch and the collector of the first transistor are connected, and the connection end is the first end of the current setting circuit. The fourth end and the fifth end of the first switch, the fifth end of the second switch and the collector of the second transistor are connected, and the connection end is the second end of the current setting circuit. The common end of the first switch is connected to one end of the first resistor, the other end of the first resistor, the base of the first transistor and the base of the second transistor are connected, the emitter of the first transistor, one end of the second resistor and one end of the third resistor are connected, and the The other end is connected to the second end of the second switch, the emitter of the second triode, one end of the fourth resistor and one end of the fifth resistor are connected, the other end of the fifth resistor is connected to the fourth end of the second switch, the other end of the third resistor, the other end of the fourth resistor and the common end of the second switch are connected, and the connection end is the negative electrode of the current setting circuit, the resistance value of the third resistor is less than or equal to the resistance value of the fourth resistor, and the resistance value of the fifth resistor satisfies: when the fourth resistor and the fifth resistor are connected in parallel, the parallel resistance value is less than or equal to the resistance value of the third resistor.

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