TWI396468B - Light source circuit and electronic apparatus - Google Patents

Description

Light source circuit and electronic device

The present invention relates to a light source circuit and an electronic device, and more particularly to a light source circuit and an electronic device capable of detecting a signal state and performing voltage conversion.

Logic gates are the basic components on an integrated circuit (IC). A simple logic gate can be made up of a transistor and can cause a high or low signal after the signal passes through the logic gate. The above high level and low level can respectively represent logical "true" and "false" or "1" and "0" among the binary, thereby implementing logical operations. Moreover, logic gates can be combined to achieve more complex logic operations.

In general, with the circuit designed by the NAND Gate, the user cannot directly judge the state of the input signal (the input signal is input from the input of the reverse gate). As a result, the complexity of input signal detection will increase.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a light source circuit and an electronic device whereby signal states can be detected and voltage conversion can be performed.

The invention provides a light source circuit comprising a first light emitting diode, a second light emitting diode and a selection unit. The cathode of the first light emitting diode receives the first input signal and the anode receives the first voltage. The cathode of the second LED receives a second input signal, the anode of which receives the first voltage. The selecting unit is configured to receive the second voltage and the third voltage, and according to the first light emitting diode and the first The second light source or the third voltage is selected as the output voltage by the conduction state of the two light emitting diodes.

In an embodiment of the invention, the light source circuit further includes a first resistor and a voltage dividing circuit. The first resistor is coupled between the first voltage and the anode of the first LED. The voltage dividing circuit has an input end and an output end, and the input end of the voltage dividing circuit is coupled to the anode of the first light emitting diode, and the output end of the voltage dividing circuit generates a voltage dividing signal and transmits the signal to the selecting unit, wherein The selection unit selects the second voltage or the third voltage as the output voltage according to the voltage division signal.

In an embodiment of the invention, the voltage dividing circuit includes a second resistor and a third resistor. The first end of the second resistor is coupled to the anode of the first light emitting diode, and the second end thereof generates a voltage dividing signal. The first end of the third resistor is coupled to the second end of the second resistor, and the second end of the third resistor is coupled to the ground.

In an embodiment of the invention, the selection unit includes a fourth resistor and a transistor. The first end of the fourth resistor receives the second voltage and the second end produces an output voltage. The base terminal of the transistor receives the divided voltage signal, the emitter terminal receives the third voltage, and the drain terminal is coupled to the second terminal of the fourth resistor.

In an embodiment of the invention, the first voltage is the same as the second voltage.

In an embodiment of the invention, the first voltage is different from the second voltage.

In an embodiment of the invention, the third voltage is a ground voltage.

The invention provides an electronic device comprising a network module, at least two light emitting diodes and a selection unit. The network module is configured to generate at least two network signals. The cathode of the light-emitting diode receives a two-network signal, and the anode of the light-emitting diode receives the first voltage. The selecting unit is configured to receive the second voltage and the third voltage, and select the second power according to the conductive state of the two light emitting diodes The voltage or the third voltage is used as the output voltage.

In an embodiment of the invention, the electronic device further includes a first resistor and a voltage dividing circuit. The first resistor is coupled between the first voltage and the anode of the two light emitting diodes. The voltage dividing circuit includes a second resistor and a third resistor. The first end of the second resistor is coupled to the anode of the two light emitting diodes, and the second end of the second resistor generates a voltage dividing signal. The first end of the third resistor is coupled to the second end of the second resistor, and the second end of the third resistor is coupled to the ground.

In an embodiment of the invention, the selection unit includes a fourth resistor and a transistor. The first end of the fourth resistor receives the second voltage and the second end produces an output voltage. The base terminal of the transistor receives the divided voltage signal, the emitter terminal receives the third voltage, and the drain terminal is coupled to the second terminal of the fourth resistor.

The present invention detects the state of an input signal (or a network signal) by the conduction (lighting) of the light emitting diode. Further, the selection unit also performs voltage conversion using the conduction or not of the light-emitting diode to generate an output voltage (that is, selects the second voltage and the third voltage as output voltages). Thereby, the present invention can detect the state of the signal and can also perform voltage conversion. In addition, in the present invention, the state of the input signal can be detected by the light emitting diode, and the state of the input signal can be detected by the output voltage, so that the convenience of detecting the input signal can be increased.

The above and other objects, features and advantages of the present invention will become more <RTIgt;

FIG. 1 is a circuit diagram of a light source circuit according to an embodiment of the invention. please Referring to FIG. 1, the light source circuit 100 provided in this embodiment may include LEDs L1 and L2 and a selection unit 110. The cathode of the light-emitting diode L1 receives the input signal IN1, and the anode of the light-emitting diode L1 receives the voltage V1. The cathode of the light-emitting diode L2 receives the input signal IN2, and the anode of the light-emitting diode L2 receives the voltage V2. The selecting unit 110 is configured to receive the voltages V2 and V3, and select the voltage V2 or V3 as the output voltage VO according to the conduction states of the LEDs L1 and L2.

In the overall operation, when one of the input signals IN1 and IN2 is a logic low voltage level (Low), or the input signals IN1 and IN2 are simultaneously at a logic low voltage level, the LEDs L1 and L2 are made therein. One is turned on (lighting), or the light emitting diodes L1 and L2 are simultaneously turned on (lighting). Thereby, the selection unit 110 selects the voltage V2 as the output voltage VO.

On the other hand, when the input signals IN1 and IN2 are simultaneously at the logic high voltage level (High), the light-emitting diodes L1 and L2 are not turned on (not emitting light). Thereby, the selection unit 110 selects the voltage V3 as the output voltage VO. In the present embodiment, the voltages of the voltages V1 and V2 are the same, and for example, the operating voltage is 5V, and the voltage V3 can be the ground voltage. Therefore, in addition to the state in which the input signals IN1 and IN2 can be viewed and displayed, the light source circuit 100 can perform a voltage conversion operation, that is, the selection unit 110 selects a voltage according to the conduction states of the LEDs L1 and L2. One of V2 and V3 is used as the output voltage VO.

In another embodiment, the user can set the voltage V2 to be different from the voltage V1 as needed, that is, the voltage V2 can be set to 3.3V or 1.8V, but the range is not limited.

2 is a detailed circuit diagram of a light source circuit according to an embodiment of the invention. Referring to FIG. 2, the light source circuit 100 may further include a resistor R1 and a voltage dividing circuit 210. The resistor R1 is coupled between the voltage V1 and the anode of the LED L1 to serve as a current limiting resistor.

The input end of the voltage dividing circuit 210 is coupled to the anode of the LED L1, and the output of the voltage dividing circuit 210 generates a voltage dividing signal and transmits it to the selecting unit 110. The selection unit 110 selects the voltage V2 or V3 as the output voltage VO according to the voltage division signal. In the present embodiment, the voltage dividing circuit 210 may include resistors R2 and R3. The first end of the resistor R2 is coupled to the anode of the LED L1, and the second end of the resistor R2 generates a voltage dividing signal. The first end of the resistor R3 is coupled to the second end of the resistor R2, and the second end of the resistor R3 is coupled to the ground GND.

In addition, the selection unit 110 may include a resistor R4 and a transistor Tr1. The first end of the resistor R4 receives the voltage V2, and the second end of the resistor R4 produces the output voltage VO. The base terminal of the transistor Tr1 receives the divided voltage signal, the emitter terminal of the transistor Tr1 receives the voltage V3, and the 汲 terminal of the transistor Tr1 is coupled to the second terminal of the resistor R4.

In the overall operation, when one of the input signals IN1 and IN2 is at a logic low voltage level, or the input signals IN1 and IN2 are simultaneously at a logic low voltage level, one of the LEDs L1 and L2 is turned on ( Light-emitting), or the light-emitting diodes L1 and L2 are simultaneously turned on (light-emitting). At this time, the voltage at the first end of the resistor R2 is lowered, and the voltage drop across the resistor R3 is also lowered. The voltage dividing signal generated by the voltage dividing circuit 210 is the same as the voltage drop across the resistor R3, and is transmitted to the base terminal of the transistor Tr1. by Since the divided voltage is lower than the turn-on voltage of the transistor Tr1, the transistor Tr1 is not turned on. On the other hand, in a state where the transistor Tr1 is not turned on, the output voltage VO is directly the voltage V2.

On the other hand, when the input signals IN1 and IN2 are at the logic high voltage level at the same time, the light-emitting diodes L1 and L2 are not turned on (not emitting light), since the light-emitting diodes L1 and L2 are not turned on, so that the resistor R3 is on The voltage drop is increased, and even if the voltage of the divided voltage signal generated by the scoring circuit 210 is increased, the transistor Tr1 is turned on. Since the transistor Tr1 is turned on, the output voltage VO is the voltage V3. In the present embodiment, the voltages of the voltages V1 and V2 are the same, and for example, the operating voltage is 5V, and the voltage V3 can be the ground voltage. Therefore, in addition to the state in which the input signals IN1 and IN2 can be viewed and displayed, the light source circuit 100 can perform a voltage conversion operation, that is, the selection unit 110 selects a voltage according to the conduction states of the LEDs L1 and L2. One of V2 and V3 is used as the output voltage VO. In another embodiment, the user can set the voltage V2 to be different from the voltage V1 as needed, that is, the voltage V2 can be set to 3.3V or 1.8V, but the range is not limited.

Further, from the above description, the correspondence relationship between the input signals IN1, IN2 and the output voltage VO can be arranged as shown in Table 1. And from the electrical dependence shown in Table 1, it can be seen that the light source circuit 100 can be used as a NAND Gate. In this way, the light source circuit 100 provided in this embodiment can not only view the state of the input signals IN1 and IN2, but also can be used as a reverse gate for voltage conversion. In addition, the light source circuit 100 of the present embodiment can detect whether the light emitting diode is directly turned on or not. The state of the input signals IN1 and IN2 can be estimated by the state of the output voltage VO, and the states of the input signals IN1 and IN2 can be estimated. Therefore, the present embodiment can increase the convenience of detecting the input signals IN1, IN2.

3 is a circuit block diagram of an electronic device according to an embodiment of the invention. Referring to FIG. 3 , the electronic device 300 provided in this embodiment includes a network module 310 , LEDs LE1 LE LEN and a selection unit 320 , where n is a positive integer greater than 1. The network module 310 is configured to generate network signals NS1~NSn. The cathodes of the light-emitting diodes LE1 to LEn receive the network signals NS1 to NSn, and the anodes of the light-emitting diodes LE1 to LEn receive the voltage V4. The selecting unit 320 is configured to receive the voltage V5 and the voltage V6, and select the voltage V5 or the voltage V6 as the output voltage VO1 according to the conduction state of the LEDs LE1 LE LEn.

In this embodiment, the number of the LEDs LE1~LEn can be adjusted according to the number of network signals NS1~NSn generated by the network module 310, that is, if the network signal is two, the light is two. There are also 2 poles, 8 network signals, 8 LEDs, and so on. Thereby, the user can check the state of the network signals NS1 to NSn by the conduction (lighting) of the light-emitting diodes.

In addition, the overall operation of the electronic device 300 can be referred to the description of the embodiment of FIG. 1, and thus will not be described herein. Moreover, the electronic device 300 of the present embodiment can also generate the same function as the anti-gate circuit. In this way, the electronic device 300 can perform voltage conversion in addition to the state of the network signals NS1 to NSn.

4 is a detailed circuit diagram of an electronic device according to an embodiment of the invention. Referring to FIG. 4 , the electronic device 300 provided in this embodiment may further include a resistor R5 and a voltage dividing circuit 410 . The resistor R5 is coupled between the voltage V4 and the anode of the LEDs LE1 LE LEn to serve as a current limiting resistor.

The input end of the voltage dividing circuit 410 is coupled to the anodes of the LEDs LE1 LE LEn, and the output of the voltage dividing circuit 410 generates a voltage dividing signal and transmits it to the selecting unit 320. The selection unit 320 selects the voltage V5 or the voltage V6 as the output voltage VO1 according to the voltage division signal. Also, the voltage dividing circuit 410 may include resistors R6 and R7. The first end of the resistor R6 is coupled to the anode of the LEDs LE1 LE LEn, and the second end of the resistor R6 generates a voltage dividing signal. The first end of the resistor R7 is coupled to the second end of the resistor R6, and the second end of the resistor R7 is coupled to the ground GND.

In addition, the selection unit 320 may include a resistor R8 and a transistor Tr2. The first end of the resistor R8 receives the voltage V5, and the second end of the resistor R8 produces the output voltage VO1. The base terminal of the transistor Tr2 receives the divided voltage signal, the emitter terminal of the transistor Tr2 receives the voltage V6, and the drain terminal of the transistor Tr2 is coupled to the second terminal of the resistor R8.

For the overall operation of the electronic device 300 of this embodiment, reference may be made to the description of the embodiment of FIG. 2, and thus no further details are provided herein. Moreover, the electronic device 300 can also generate the same function as the anti-gate circuit. In this way, in addition to the state of the network signals NS1 to NSn, the electronic device 300 can perform voltage conversion to generate an output voltage, and can also detect the state of the network signals NS1 to NSn by the output voltage.

In summary, the present invention detects the state of an input signal (or a network signal) by the conduction (lighting) of the light emitting diode. Further, the selection unit also performs voltage conversion using the conduction or not of the light-emitting diode to generate an output voltage (that is, selects the second voltage and the third voltage as output voltages). Thereby, the present invention can detect the state of the signal and can also perform voltage conversion. In addition, in the present invention, the state of the input signal can be detected by the light emitting diode, and the state of the input signal can be detected by the output voltage, so that the convenience of detecting the input signal can be increased.

While the present invention has been described in its preferred embodiments, the present invention is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application.

100‧‧‧Light source circuit

L1, L2, LE1~LEn‧‧‧Light Emitting Diodes

V1, V2, V3, V4, V5, V6‧‧‧ voltage

VO, VO1‧‧‧ output voltage

300‧‧‧Electronic devices

110, 320‧‧‧Selection unit

R1~R8‧‧‧ resistance

Tr1, Tr2‧‧‧ transistor

IN1, IN2‧‧‧ input signal

210, 410‧‧‧voltage circuit

310‧‧‧Network Module

NS1~NSn‧‧‧ network signal

1 is a circuit block diagram of a light source circuit according to an embodiment of the invention.

2 is a detailed circuit block diagram of a light source circuit according to an embodiment of the invention.

3 is a circuit block diagram of an electronic device according to an embodiment of the invention. Figure.

4 is a detailed circuit block diagram of an electronic device according to an embodiment of the invention.

100‧‧‧Light source circuit

L1, L2‧‧‧Light Emitting Diodes

IN1, IN2‧‧‧ input signal

V1, V2, V3‧‧‧ voltage

110‧‧‧Selection unit

VO‧‧‧ output voltage

Claims (10)

A light source circuit comprising: a first light emitting diode, a cathode of which receives a first input signal, an anode of which receives a first voltage; a second light emitting diode whose cathode receives a second input signal, The anode receives the first voltage; and a selection unit is configured to receive a second voltage and a third voltage, and respectively coupled to the first LED and the anode of the second LED to The second light source or the third voltage is selected as an output voltage by the first light emitting diode and the second light emitting diode. The light source circuit of claim 1, further comprising: a first resistor coupled between the first voltage and the anode of the first LED; and a voltage dividing circuit having a An input end and an output end coupled to the anode of the first LED, the output end generates a voltage division signal and is transmitted to the selection unit, wherein the selection unit is based on the voltage division signal The second voltage or the third voltage is selected as the output voltage. The light source circuit of claim 2, wherein the voltage dividing circuit comprises: a second resistor having a first end coupled to the anode of the first light emitting diode and a second end generating the minute And a third resistor, the first end of which is coupled to the second end of the second resistor, and the second end of which is coupled to the ground. The light source circuit of claim 1, wherein the selecting unit comprises: a fourth resistor, the first end receiving the second voltage, the second end generating the output voltage; and a transistor, the base thereof The voltage receiving signal is extremely received, the emitter terminal receives the third voltage, and the drain terminal is coupled to the second terminal of the fourth resistor. The light source circuit of claim 1, wherein the first voltage is the same as the second voltage. The light source circuit of claim 1, wherein the first voltage is different from the second voltage. The light source circuit of claim 1, wherein the third voltage is a ground voltage. An electronic device includes: a network module for generating at least two network signals; at least two light emitting diodes, wherein the cathodes of the light emitting diodes are coupled to the network module to receive the two network signals The anodes of the light emitting diodes receive a first voltage; and a selection unit for receiving a second voltage and a third voltage, and respectively coupling the anodes of the light emitting diodes to The second voltage or the third voltage is selected as an output voltage by the conduction state of the light emitting diode. The electronic device of claim 8, further comprising: a first resistor coupled between the first voltage and the anodes of the light emitting diodes; a voltage dividing circuit comprising: a second resistor having a first end coupled to the anodes of the light emitting diodes, a second end generating a voltage dividing signal; and a third resistor having a first end coupled The second end of the second resistor is coupled to the ground end; wherein the selecting unit selects the second voltage or the third voltage as the output voltage according to the voltage dividing signal. The electronic device of claim 8, wherein the selecting unit comprises: a fourth resistor, the first end receiving the second voltage, the second end generating the output voltage; and a transistor, the base thereof The voltage receiving signal is extremely received, the emitter terminal receives the third voltage, and the drain terminal is coupled to the second terminal of the fourth resistor.