TW201301703A - Power transmission system, device and protection circuit having power supply protection function - Google Patents

Abstract

A protection circuit is electrically connected between a DC(direct current) power supplier providing DC power and a load, and the protection circuit includes: a voltage comparator electrically connected to a DC power supplier to detect DC power to obtain a detected voltage value, and according to a safety range, the detected voltage value that is compared to be within a safety range or not to provide a control signal ; and a switch having a first end receiving DC electricity, a second end electrically connected to the load, and a control end receiving the control signal. According to the variations of the logic level of the control signal, the first and second ends of the switch can be switched between conducting state and non-conducting state without transferring the DC current power to the load.

Description

Transmission system, device and protection circuit with power protection function

The invention relates to a system, a device and a circuit, in particular to a power transmission system, a device and a protection circuit with a power supply protection function.

As shown in FIG. 1, a conventional power transmission system 1 includes a DC power supply 10 and a load 11.

The DC power supply 1 is used to provide DC power.

The load 11 is electrically connected to the DC power supply 10 to receive the DC power.

However, the conventional power transmission system 1 has the following disadvantages:

1. If the voltage of the DC power is higher than the standard specification of the load 11, the load 11 will be burned.

2. If the voltage of the DC power is lower than the standard specification of the load 11, the load 11 is to maintain its rated power, and an excess current is drawn from the DC power supply 10, causing the DC power supply 10 to burn.

Accordingly, a first object of the present invention is to provide a power transmission system having a power supply protection function that solves the above problems.

The power transmission protection system includes: a load; and a power transmission device having a power supply protection function, including: a DC power supply for providing DC power; and a protection circuit electrically connected to the DC power supply Between the supplier and the load, and having: a voltage comparator electrically connected to the DC power supply to detect the DC power, obtaining a detected voltage value, and comparing the detected voltage according to a safe range Whether the value is within the safe range to correspondingly provide a control signal that changes at a low and high logic level; and a switch having a first end electrically connected to the DC power supply to receive the DC power, Electrically connected to the second end of the load, and a control terminal electrically connected to the voltage comparator to receive the control signal, and the first and second ends of the switch are changed according to a logic level change of the control signal Switching between a conducting state and a non-conducting state; when the detected voltage value is not within the safe range, the switch is controlled by the control signal and is in a non-conducting state, and is not DC power from the DC power supply is transmitted to the load.

A second object of the present invention is to provide a power transmission device having a power supply protection function.

The power transmission protection device is adapted to be electrically connected to a load, and comprises: a DC power supply for providing DC power; and a protection circuit electrically connected to the DC power supply and the load And having: a voltage comparator electrically connected to the DC power supply to detect the DC power to obtain a detected voltage value, and comparing whether the detected voltage value is in the safe range according to a safe range Correspondingly, a control signal is provided for changing at a low and high logic level; and a switch having a first end electrically connected to the DC power supply to receive the DC power, and an electrical connection to the load a second end, and a control terminal electrically connected to the voltage comparator to receive the control signal, and the first state and the second end of the switch are in a conducting state according to a logic level change of the control signal Switching between the on states; when the detected voltage value is not within the safe range, the switch is controlled by the control signal to be in a non-conducting state, and not from the DC power supply DC power delivered to the load.

A third object of the present invention is to provide a protection circuit.

The protection circuit is adapted to be electrically connected between the DC power supply and a load, the DC power supply is configured to provide DC power, and the protection circuit comprises: a voltage comparator electrically connected to the DC power supply Detecting the DC power to obtain a detected voltage value, and comparing whether the detected voltage value is within the safe range according to a safe range, correspondingly providing a control signal at a low and high logic level change And a switch having a first end electrically connected to the DC power supply to receive the DC power, a second end electrically connected to the load, and an electrical connection to the voltage comparator to receive the control signal The control terminal switches between the conductive state and the non-conductive state between the first and second ends of the switch according to the logic level change of the control signal; when the detected voltage value is not within the safe range The switch is controlled by the control signal to be in a non-conducting state, and does not transfer DC power from the DC power supply to the load.

The above and other technical contents, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments.

As shown in FIG. 2, a preferred embodiment of the power transmission system having the power supply protection function of the present invention comprises: a load 3, and a power transmission device 2 having a power supply protection function.

The power transmission device 2 having the power supply protection function is electrically connected to the load 3, and includes a DC power supply 20 and a protection circuit 21.

The DC power supply 20 is used to provide DC power.

The protection circuit 21 is electrically connected between the DC power supply and the load, and includes a voltage comparator 22 and a switch S.

The voltage comparator 22 is electrically connected to the DC power supply 20 to detect the DC power, and obtains a detected voltage value Va, and compares whether the detected voltage value is within the safe range according to a safe range. Correspondingly, a control signal is provided which changes at a low and high logic level. The safety range is less than a first reference voltage Vref1 and greater than a second reference voltage Vref2, and Vref1>Vref2. The voltage comparator 22 includes a first resistor R1, a second resistor R2, a first operational amplifier unit OP1, a second operational amplifier unit OP2, a logic unit OR, and a third resistor R3.

The first resistor R1 has a first end electrically connected to the DC power supply 20 to receive the DC power, and a second end.

The second resistor R2 has a first end electrically connected to the second end of the first resistor R1 and providing the detected voltage value Va, and a grounded second end.

The first operational amplifying unit OP1 has a non-inverting input terminal (+) electrically connected to the second end of the first resistor R1 to receive the detected voltage value Va, and an inversion of receiving the first reference voltage Vref1. The input terminal (-), and an output terminal for providing a first logic signal Vo1.

The second operational amplifying unit OP2 has a non-inverting input terminal (+) receiving the second reference voltage Vref2, and a second terminal electrically connected to the first resistor R1 to receive the inverted phase of the detected voltage value Va. The input terminal (-), and an output terminal for providing a second logic signal Vo2.

The OR logic unit OR is electrically connected to the output ends of the two operational amplification units OP2 to receive the first and second logic signals Vo1 and Vo2, respectively, and perform or logical operations to obtain the control signals.

The third resistor R3 has a first end electrically connected to the OR logic unit OR to receive the control signal, and a second end providing the control signal.

The switch S has a first end electrically connected to the DC power supply 20 for receiving the DC power, a second end electrically connected to the load 3, and an electrical connection to the voltage comparator 22 for receiving the control The control end of the signal switches between the first state and the second end of the switch S between the conductive state and the non-conductive state according to the logic level change of the control signal. In this embodiment, the switch S is a P-type MOS field-effect transistor, the first end of which is a drain, the second end is a source, and the control end is electrically connected to the second end of the third resistor R3. Gate.

When the detected voltage value is within the safe range (Vref1>Va>Vref2), the switch S is controlled by the control signal to be in an on state to transmit DC power from the DC power supply 20 via the switch S. Go to the load 3. It is further described that if the voltage Vin of the DC power is normal and the detected voltage value Va is within the safe range, the first operational amplification unit OP1 compares the detected voltage value Va with the first reference voltage Vref1. The second logic signal Vo1 is at a low logic level, and the second operational amplifier unit OP2 compares the detected voltage value with the second reference voltage Vref2 to make the second logic signal Vo2 at a low logic level. The OR logic unit OR turns the control signal of the P-type transistor on according to the first and second logic signals Vo1 and Vo2, both of which are at a low logic level, at a low logic level.

When the detected voltage value Va is not within the safe range, the switch S is controlled by the control signal to be in a non-conducting state, and the DC power from the DC power supply 20 is not transmitted to the load 3. It is further explained that if the voltage Vin of the DC power is too high and the detection voltage value Va is not within the safe range, the first operational amplification unit OP1 compares the detection voltage Va with the first reference voltage Vref1 ( Va>Vref1), the first logic signal Vo1 is at a high logic level, and the second operational amplification unit OP2 compares the detection voltage Va with the second reference voltage Vref2 (Va>Vref2) to make the second logic The signal Vo2 is at a low logic level, and the OR logic unit OR has its control signal at a high logic level according to the first and second logic signals Vo1 and Vo2, so that the switch S of the P-type transistor is not turned on. Without transmitting the DC power having an overvoltage to the load 3, the load 3 can be protected from burning.

If the voltage of the DC power is too low and the detected voltage value is not within the safe range, the first operational amplifier unit compares the detected voltage value with the first reference voltage (Va<Vref1) to make the first A logic signal Vo1 is at a low logic level, and the second operational amplifier unit OP2 compares the detected voltage value with the second reference voltage (Va<Vref2) to bring the second logic signal Vo2 to a high logic level. The OR logic unit OR causes the control signal to be at a high logic level according to the first and second logic signals Vo1 and Vo2, so that the switch S of the P-type transistor is not turned on, and the voltage of the DC power can be prevented from being insufficient. The load 3 draws an excess current from the DC power supply 20 to maintain its rated power, thereby protecting the DC power supply 20 from burnout.

As shown in FIG. 3, a variation of this embodiment is that the OR logic unit OR is changed to an inverting or logic unit NOR, and the P-type transistor is changed to an N-type transistor as the switch S. The inverting OR logic unit NOR is electrically connected to the output ends of the two operational amplifying units OP2 to respectively receive the first and second logic signals, and accordingly perform an inversion or logic operation to obtain the control signals. The switch S is an N-type MOS field effect transistor, the first end of which is a drain, the second end is a source, and the control end is a gate electrically connected to the second end of the third resistor R3.

In summary, the above embodiment has the following advantages:

1. If the voltage Vin of the DC power is higher than the standard specification of the load 3, the DC circuit power is not transmitted to the load 3 by the protection circuit 22, and the load 3 can be protected from burning.

2. If the voltage of the DC power is lower than the standard specification of the load 3, the protection circuit 22 is used to prevent the DC power from being transmitted to the load 3, and the load 3 can be prevented from extracting excess current from the DC power supply 20, and The DC power supply 20 can be protected from burning.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent.

2. . . Power transmission device with power protection function

20. . . DC power supply

twenty one. . . protect the circuit

twenty two. . . Voltage comparator

R1. . . First resistance

R2. . . Second resistance

R3. . . Third resistance

OP1. . . First operational amplification unit

OP2. . . Second operational amplification unit

OR. . . Logical unit

NOR. . . Inverting or logic unit

S. . . switch

3. . . load

1 is a circuit diagram of a conventional power transmission system;

2 is a circuit diagram of a preferred embodiment of a power transmission system having a power supply protection function of the present invention; and

Figure 3 is a circuit diagram of a variation of the preferred embodiment.

2. . . Power transmission device with power protection function

20. . . DC power supply

twenty one. . . protect the circuit

twenty two. . . Voltage comparator

S. . . switch

3. . . load

Claims (16)

A power transmission system having a power supply protection function, comprising: a load; and a power transmission device having a power supply protection function, comprising: a DC power supply for providing DC power; and a protection circuit electrically connected to the DC power supply Between the supplier and the load, and having: a voltage comparator electrically connected to the DC power supply to detect the DC power, obtaining a detected voltage value, and comparing the detected voltage according to a safe range Whether the value is within the safe range to correspondingly provide a control signal that changes at a low and high logic level; and a switch having a first end electrically connected to the DC power supply to receive the DC power, Electrically connected to the second end of the load, and a control terminal electrically connected to the voltage comparator to receive the control signal, and the first and second ends of the switch are changed according to a logic level change of the control signal Switching between a conducting state and a non-conducting state; when the detected voltage value is not within the safe range, the switch is controlled by the control signal to be in a non-conducting state, and The DC power from the DC power supply is transmitted to the load. A power transmission system having a power supply protection function according to claim 1, wherein the voltage comparator comprises: a first resistor having a first end electrically connected to the DC power supply to receive the DC power And a second end; a second resistor having a first end electrically connected to the second end of the first resistor and providing the detection voltage, and a grounded second end; a first operational amplification unit Having a non-inverting input electrically coupled to the second end of the first resistor for receiving the detected voltage, an inverting input receiving the first reference voltage, and an output providing a first logic signal end. a second operational amplification unit having a non-inverting input terminal for receiving the second reference voltage, an inverting input terminal electrically connected to the second end of the first resistor for receiving the detection voltage, and providing a An output of the second logic signal; and an OR logic unit electrically connected to the output terminals of the two operational amplification units to respectively receive the first and second logic signals, and perform or logical operations to obtain the control signal. A power transmission system with a power supply protection function according to claim 2, wherein the voltage comparator further comprises: a third resistor having a first end electrically connected to the OR logic unit to receive the control signal And a second end that provides the control signal. According to the power transmission system with the power supply protection function described in claim 2, if the voltage of the DC power is too high and the detected voltage value is not within the safe range, the first operational amplification unit compares the The detecting voltage value is greater than the first reference voltage to cause the first logic signal to be at a high logic level, and the second operational amplifying unit compares the detected voltage value to be greater than the second reference voltage to cause the second logic signal to be The logic level is low, and the OR operation unit causes the control signal to be at a high logic level according to the first and second logic signals, so that the switch is not turned on. A power transmission system having a power supply protection function according to claim 1, wherein the voltage comparator comprises: a first resistor having a first end electrically connected to the DC power supply to receive the DC power And a second end; a second resistor having a first end electrically connected to the second end of the first resistor and providing the detection voltage, and a grounded second end; a first operational amplification unit Having a non-inverting input electrically coupled to the second end of the first resistor for receiving the detected voltage, an inverting input receiving the first reference voltage, and an output providing a first logic signal end. a second operational amplification unit having a non-inverting input terminal for receiving the second reference voltage, an inverting input terminal electrically connected to the second end of the first resistor for receiving the detection voltage, and providing a An output of the second logic signal; an inverting or logic unit electrically coupled to the output of the two operational amplification units to receive the first and second logic signals, respectively, and performing an inversion or logic operation to obtain the And a third resistor having a first end electrically coupled to the OR logic unit to receive the control signal, and a second end providing the control signal. According to the power transmission protection system of claim 1, wherein when the detected voltage value is within the safe range, the switch is controlled by the control signal to be in an on state to receive the DC The DC power of the power supply is delivered to the load via the switch. A power transmission device with power supply protection function, is suitable for electrically connecting to a load, and includes: a DC power supply for providing DC power; and a protection circuit electrically connected to the DC power supply and the load And having: a voltage comparator electrically connected to the DC power supply to detect the DC power to obtain a detected voltage value, and comparing whether the detected voltage value is in the safe range according to a safe range Correspondingly, a control signal is provided for changing at a low and high logic level; and a switch having a first end electrically connected to the DC power supply to receive the DC power, and an electrical connection to the load a second end, and a control terminal electrically connected to the voltage comparator to receive the control signal, and the first state and the second end of the switch are in a conducting state according to a logic level change of the control signal Switching between the on states; when the detected voltage value is not within the safe range, the switch is controlled by the control signal to be in a non-conducting state, and not from the DC power supply DC power delivered to the load. A power transmission device with a power supply protection function according to claim 7 , wherein the voltage comparator comprises: a first resistor having a first end electrically connected to the DC power supply to receive the DC power And a second end; a second resistor having a first end electrically connected to the second end of the first resistor and providing the detection voltage, and a grounded second end; a first operational amplification unit Having a non-inverting input electrically coupled to the second end of the first resistor for receiving the detected voltage, an inverting input receiving the first reference voltage, and an output providing a first logic signal a second operational amplifier unit having a non-inverting input terminal for receiving the second reference voltage, an inverting input terminal electrically connected to the second end of the first resistor for receiving the detection voltage, and a Providing an output of a second logic signal; and an OR logic unit electrically connected to the outputs of the two operational amplification units to respectively receive the first and second logic signals, and performing or logical operations to obtain the control signal. A power transmission device with a power supply protection function according to claim 8 , wherein the voltage comparator further comprises: a third resistor having a first end electrically connected to the OR logic unit to receive the control signal And a second end that provides the control signal. A power transmission device with a power supply protection function according to claim 7 , wherein the voltage comparator comprises: a first resistor having a first end electrically connected to the DC power supply to receive the DC power And a second end; a second resistor having a first end electrically connected to the second end of the first resistor and providing the detection voltage, and a grounded second end; a first operational amplification unit Having a non-inverting input electrically coupled to the second end of the first resistor for receiving the detected voltage, an inverting input receiving the first reference voltage, and an output providing a first logic signal end. a second operational amplification unit having a non-inverting input terminal for receiving the second reference voltage, an inverting input terminal electrically connected to the second end of the first resistor for receiving the detection voltage, and providing a An output of the second logic signal; an inverting or logic unit electrically coupled to the output of the two operational amplification units to receive the first and second logic signals, respectively, and performing an inversion or logic operation to obtain the And a third resistor having a first end electrically coupled to the OR logic unit to receive the control signal, and a second end providing the control signal. A protection circuit adapted to be electrically connected between a DC power supply and a load, the DC power supply for providing DC power, and the protection circuit includes: a voltage comparator electrically connected to the DC power supply Detecting the DC power to obtain a detected voltage value, and comparing whether the detected voltage value is within the safe range according to a safe range, correspondingly providing a control signal at a low and high logic level change And a switch having a first end electrically connected to the DC power supply to receive the DC power, a second end electrically connected to the load, and an electrical connection to the voltage comparator to receive the control signal The control terminal switches between the conductive state and the non-conductive state between the first and second ends of the switch according to the logic level change of the control signal; when the detected voltage value is not within the safe range The switch is controlled by the control signal to be in a non-conducting state, and does not transfer DC power from the DC power supply to the load. The protection circuit of claim 11, wherein the voltage comparator comprises: a first resistor having a first end electrically connected to the DC power supply to receive the DC power, and a second a second resistor having a first end electrically connected to the second end of the first resistor and providing the detection voltage, and a grounded second end; a first operational amplification unit having an electrical connection a second non-inverting input terminal for receiving the detection voltage, an inverting input terminal for receiving the first reference voltage, and an output terminal for providing a first logic signal; and a second The operational amplification unit has a non-inverting input terminal for receiving the second reference voltage, an inverting input terminal electrically connected to the second end of the first resistor to receive the detection voltage, and a second logic And an output unit of the signal, and a logic unit, electrically connected to the output ends of the two operational amplification units to respectively receive the first and second logic signals, and perform or logical operations to obtain the control signal. The protection circuit of claim 12, wherein the voltage comparator further comprises: a third resistor having a first end electrically connected to the OR logic unit to receive the control signal, and a providing The second end of the control signal. According to the protection circuit of claim 12, if the voltage of the DC power is too high and the detected voltage value is not within the safe range, the first operational amplifier unit compares the detected voltage value to be greater than The first reference voltage causes the first logic signal to be at a high logic level, and the second operational amplification unit compares the detected voltage value to be greater than the second reference voltage to cause the second logic signal to be at a low logic level. Further, the OR logic unit causes the control signal to be at a high logic level according to the first and second logic signals, so that the switch is not turned on. According to the protection circuit of claim 11, wherein when the detected voltage value is within the safe range, the switch is controlled by the control signal to be in a conducting state to direct the DC from the DC power supply. Power is delivered to the load via the switch. The protection circuit of claim 11, wherein the voltage comparator comprises: a first resistor having a first end electrically connected to the DC power supply to receive the DC power, and a second a second resistor having a first end electrically connected to the second end of the first resistor and providing the detection voltage, and a grounded second end; a first operational amplification unit having an electrical connection The second end of the first resistor receives a non-inverting input of the detection voltage, an inverting input terminal receiving the first reference voltage, and an output terminal providing a first logic signal. a second operational amplification unit having a non-inverting input terminal for receiving the second reference voltage, an inverting input terminal electrically connected to the second end of the first resistor for receiving the detection voltage, and providing a An output of the second logic signal; an inverting or logic unit electrically coupled to the output of the two operational amplification units to receive the first and second logic signals, respectively, and performing an inversion or logic operation to obtain the And a third resistor having a first end electrically coupled to the OR logic unit to receive the control signal, and a second end providing the control signal.