Disclosure of Invention
In order to overcome the defects of the prior art, the invention provides a circuit with forward-switching and reverse-switching formed by an operational amplifier, which has the specific technical scheme that:
the device comprises a charge-discharge module (1), a reference module (2) and an operational amplifier module (3);
the operational amplifier module (3) is a comparator circuit composed of an operational amplifier, and generates corresponding control logic signals which are sequentially switched on or switched off in a reverse order according to the working states of the charge-discharge module (1) and the reference module (2) and are used for transmitting, driving or indicating a next-stage circuit;
the charge-discharge module (1) comprises a single-pole double-throw switch S1, a discharge resistor R1, a charge-discharge resistor R2 and a charge-discharge capacitor C1; one fixed end of the single-pole double-throw switch S1 is an a end and is connected with one end of a discharge resistor R1 to play a role in reverse turn off, and the other end of the discharge resistor R1 is connected with a power ground; the other fixed end of the single-pole double-throw switch S1 is a b end and is connected with a power supply VCC to play a role in sequential connection; the common end of the single-pole double-throw switch S1 is a com end and is connected with one end of a charge and discharge resistor R2, the other end of the charge and discharge resistor R2 is connected with one end of a charge and discharge capacitor C1, the connection point is set as a Tcom end, and the other end of the charge and discharge capacitor C1 is connected with the power ground;
the reference module (2) comprises a direct current source A1, a bias resistor R3, a reference resistor Rref1 and a reference resistor Rref 2; the negative end of the direct current source A1 is connected with the power ground, the positive end thereof is connected with one end of a bias resistor R3, the other end of the bias resistor R3 is connected with one end of a reference resistor Rref2, the connection point is set as a Vref2 end, the other end of the reference resistor Rref2 is connected with one end of a reference resistor Rref1, the connection point is set as a Vref1 end, and the other end of the reference resistor Rref1 is connected with the power ground;
the operational amplifier module (3) comprises an operational amplifier U1 and an operational amplifier U2, wherein the in-phase end of the operational amplifier U1 and the in-phase end of the operational amplifier U2 are both connected with the Tcom end of the charge-discharge module (1), the inverting end of the operational amplifier U1 is connected with the Vref1 end of the reference module (2), the inverting end of the operational amplifier U2 is connected with the Vref2 end of the reference module (2), the output end of the operational amplifier U1 is OUT1, and the output end of the operational amplifier U2 is OUT2, namely the operational amplifier module (3) realizes positive logic control of high-level turn-on and low-level turn-off;
the charging and discharging module (1) is provided with two working loops, wherein the first loop is that a power supply VCC, a b end and a com end of a single-pole double-throw switch S1, a charging and discharging resistor R2, a charging and discharging capacitor C1 and a power supply ground form a charging loop, the rising speed of the voltage of a Tcom end during charging is directly related to a time constant, and the time constant is the product of the charging and discharging resistor R2 and the charging and discharging capacitor C1; the second loop is a discharge loop formed by a power ground, a discharge resistor R1, the a end and the com end of the single-pole double-throw switch S1, a charge-discharge resistor R2, a charge-discharge capacitor C1 and the power ground, the voltage at the Tcom end is decreased quickly and slowly and is directly related to another time constant, and the time constant is the sum of the discharge resistor R1 and the charge-discharge resistor R2 and is multiplied by the charge-discharge capacitor C1;
the constant reference voltage loop generated by the reference module (2) consists of a direct current source A1, a bias resistor R3, a reference resistor Rref2 and a reference resistor Rref1, the size of the reference voltage is determined by parameters of the direct current source A1, the bias resistor R3, the reference resistor Rref2 and the reference resistor Rref1, wherein the voltage at the Vref1 end is smaller than the voltage at the Vref2 end;
throwing the single-pole double-throw switch S1 to the end b, gradually increasing the voltage of the Tcom end, when the voltage is higher than the voltage of the Vref1 end, preferentially outputting a high level by the output end OUT1 of the operational amplifier U1, when the voltage is higher than the voltage of the Vref2 end, outputting a high level by the output end OUT2 of the operational amplifier U2 later than the output end OUT1, and realizing the sequential turn-on of positive logic, wherein the turn-on time interval of the output end OUT1 and the output end OUT2 can be arbitrarily controlled by adjusting the time constant of a charging loop;
the single-pole double-throw switch S1 is thrown to the a end, the voltage of the Tcom end gradually drops, when the voltage is lower than the voltage of the Vref2 end, the output end OUT2 of the operational amplifier U2 preferentially outputs low level, when the voltage is lower than the voltage of the Vref1 end, the output end OUT1 of the operational amplifier U1 outputs low level later than the output end OUT2, the reverse order turn-off of positive logic is realized, and the turn-off time interval of the output end OUT2 and the output end OUT1 can be arbitrarily controlled by adjusting the time constant of a discharge loop.
Further, a single-pole double-throw switch S1 in the charge-discharge module (1) is replaced by a single-pole single-throw switch S2 and a single-pole single-throw switch S3;
namely, one end of the single-pole single-throw switch S3 is connected with a power supply VCC, the other end of the single-pole single-throw switch S3 is connected with one end of a charge and discharge resistor R2, and the other end of the charge and discharge resistor R2 is connected with a Tcom end;
one end of the single-pole single-throw switch S2 is connected with one end of the discharge resistor R1, the other end of the discharge resistor R1 is connected with the power ground, the other end of the single-pole single-throw switch S2 is connected with the Tcom end and one end of the charge-discharge capacitor C1, and the other end of the charge-discharge capacitor C1 is connected with the power ground.
Further, the discharge resistor R1, the charge and discharge resistor R2, or the charge and discharge capacitor C1 in the charge and discharge module (1) may be replaced by an adjustable discharge resistor Rw1, an adjustable charge and discharge resistor Rw2, or an adjustable charge and discharge capacitor Cw 1; the bias resistor Rw3, the reference resistor Rrefw1 or the reference resistor Rrefw2 in the reference module (2) can be replaced by an adjustable bias resistor Rw3, an adjustable reference resistor Rrefw1 or an adjustable reference resistor Rrefw 2.
Further, the dc current source a1 in the reference module (2) is replaced by a dc voltage source V1, the negative terminal is connected to the power ground, and the positive terminal is connected to one end of a bias resistor R3.
Furthermore, the reference resistor Rref2 in the reference module (2) is replaced by a reference resistor Rref2, a reference resistor Rref3, … and a reference resistor Rrefn which are composed of a plurality of resistor strings, wherein n is more than or equal to 3, and the generated connecting points are correspondingly set as a Vref2 end, a Vref3 end, … and Vrefn end; correspondingly, the operational amplifier U2 in the operational amplifier module (3) is also replaced by an operational amplifier U2, operational amplifiers U3 and … and an operational amplifier Un, in addition, the inverting terminal of the operational amplifier U2 is correspondingly connected to a Vref2 terminal, the inverting terminal of the operational amplifier U3 is correspondingly connected to a Vref3 terminal and …, and the inverting terminal of the operational amplifier Un is correspondingly connected to a Vrefn terminal; meanwhile, the in-phase terminals of all the operational amplifiers are connected with the Tcom terminal; finally, the output terminal OUT2 is set to the output terminal OUT2, the output terminals OUT3, …, and the output terminal OUTn, respectively.
Furthermore, the charge-discharge module (1) and the reference module (2) are kept unchanged, the in-phase end of the operational amplifier U1 is correspondingly connected to the Vref1 end, the in-phase end of the operational amplifier U2 is correspondingly connected to the Vref2 end and … end, and the in-phase end of the operational amplifier Un is correspondingly connected to the Vrefn end; the inverting terminals of all the operational amplifiers are connected with the Tcom terminal, wherein n is more than or equal to 2; compared with the positive logic control, the negative logic control can be realized, namely low-level switching-on and high-level switching-off.
The invention has the advantages that the forward-switching and reverse-switching circuit formed by the operational amplifier not only can arbitrarily expand the capacity of the number of the controlled objects at low cost, but also can arbitrarily adjust the turn-on time interval and the turn-off time interval of the adjacent controlled objects, and has the outstanding advantages of strong universality, simple structure, small volume and low power consumption.
Detailed Description
In order that the above objects, features and advantages of the present invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings.
As shown in fig. 1, a typical schematic diagram of a forward-to-reverse switching circuit formed by an operational amplifier according to the present invention includes a charge-discharge module (1), a reference module (2), and an operational amplifier module (3);
the operational amplifier module (3) is a comparator circuit composed of an operational amplifier, and generates corresponding control logic signals which are sequentially switched on or switched off in a reverse order according to the working states of the charge-discharge module (1) and the reference module (2) and are used for transmitting, driving or indicating a next-stage circuit;
the charge-discharge module (1) comprises a single-pole double-throw switch S1, a discharge resistor R1, a charge-discharge resistor R2 and a charge-discharge capacitor C1; one fixed end of the single-pole double-throw switch S1 is an a end and is connected with one end of a discharge resistor R1 to play a role in reverse turn off, and the other end of the discharge resistor R1 is connected with a power ground; the other fixed end of the single-pole double-throw switch S1 is a b end and is connected with a power supply VCC to play a role in sequential connection; the common end of the single-pole double-throw switch S1 is a com end and is connected with one end of a charge and discharge resistor R2, the other end of the charge and discharge resistor R2 is connected with one end of a charge and discharge capacitor C1, the connection point is set as a Tcom end, and the other end of the charge and discharge capacitor C1 is connected with the power ground;
the reference module (2) comprises a direct current source A1, a bias resistor R3, a reference resistor Rref1 and a reference resistor Rref 2; the negative end of the direct current source A1 is connected with the power ground, the positive end thereof is connected with one end of a bias resistor R3, the other end of the bias resistor R3 is connected with one end of a reference resistor Rref2, the connection point is set as a Vref2 end, the other end of the reference resistor Rref2 is connected with one end of a reference resistor Rref1, the connection point is set as a Vref1 end, and the other end of the reference resistor Rref1 is connected with the power ground;
the operational amplifier module (3) comprises an operational amplifier U1 and an operational amplifier U2, wherein the in-phase end of the operational amplifier U1 and the in-phase end of the operational amplifier U2 are both connected with the Tcom end of the charge-discharge module (1), the inverting end of the operational amplifier U1 is connected with the Vref1 end of the reference module (2), the inverting end of the operational amplifier U2 is connected with the Vref2 end of the reference module (2), the output end of the operational amplifier U1 is OUT1, and the output end of the operational amplifier U2 is OUT2, namely the operational amplifier module (3) realizes positive logic control of high-level turn-on and low-level turn-off;
the charging and discharging module (1) is provided with two working loops, wherein the first loop is that a power supply VCC, a b end and a com end of a single-pole double-throw switch S1, a charging and discharging resistor R2, a charging and discharging capacitor C1 and a power supply ground form a charging loop, the rising speed of the voltage of a Tcom end during charging is directly related to a time constant, and the time constant is the product of the charging and discharging resistor R2 and the charging and discharging capacitor C1; the second loop is a discharge loop formed by a power ground, a discharge resistor R1, the a end and the com end of the single-pole double-throw switch S1, a charge-discharge resistor R2, a charge-discharge capacitor C1 and the power ground, the voltage at the Tcom end is decreased quickly and slowly and is directly related to another time constant, and the time constant is the sum of the discharge resistor R1 and the charge-discharge resistor R2 and is multiplied by the charge-discharge capacitor C1;
the constant reference voltage loop generated by the reference module (2) consists of a direct current source A1, a bias resistor R3, a reference resistor Rref2 and a reference resistor Rref1, the size of the reference voltage is determined by parameters of the direct current source A1, the bias resistor R3, the reference resistor Rref2 and the reference resistor Rref1, wherein the voltage at the Vref1 end is smaller than the voltage at the Vref2 end;
throwing the single-pole double-throw switch S1 to the end b, gradually increasing the voltage of the Tcom end, when the voltage is higher than the voltage of the Vref1 end, preferentially outputting a high level by the output end OUT1 of the operational amplifier U1, when the voltage is higher than the voltage of the Vref2 end, outputting a high level by the output end OUT2 of the operational amplifier U2 later than the output end OUT1, and realizing the sequential turn-on of positive logic, wherein the turn-on time interval of the output end OUT1 and the output end OUT2 can be arbitrarily controlled by adjusting the time constant of a charging loop;
the single-pole double-throw switch S1 is thrown to the a end, the voltage of the Tcom end gradually drops, when the voltage is lower than the voltage of the Vref2 end, the output end OUT2 of the operational amplifier U2 preferentially outputs low level, when the voltage is lower than the voltage of the Vref1 end, the output end OUT1 of the operational amplifier U1 outputs low level later than the output end OUT2, the reverse order turn-off of positive logic is realized, and the turn-off time interval of the output end OUT2 and the output end OUT1 can be arbitrarily controlled by adjusting the time constant of a discharge loop.
Fig. 2 is a second exemplary schematic diagram of a forward-switching/reverse-switching circuit formed by an operational amplifier according to the present invention, which is based on fig. 1, and is implemented by replacing a single-pole double-throw switch S1 in a charge-discharge module (1) with a single-pole single-throw switch S2 and a single-pole single-throw switch S3;
namely, one end of the single-pole single-throw switch S3 is connected with a power supply VCC, the other end of the single-pole single-throw switch S3 is connected with one end of a charge and discharge resistor R2, and the other end of the charge and discharge resistor R2 is connected with a Tcom end;
one end of the single-pole single-throw switch S2 is connected with one end of the discharge resistor R1, the other end of the discharge resistor R1 is connected with the power ground, the other end of the single-pole single-throw switch S2 is connected with the Tcom end and one end of the charge-discharge capacitor C1, and the other end of the charge-discharge capacitor C1 is connected with the power ground.
As shown in fig. 3, which is a third exemplary schematic diagram of a forward-switching and reverse-switching circuit formed by an operational amplifier according to the present invention, on the basis of fig. 1, a discharge resistor R1, a charge-discharge resistor R2, or a charge-discharge capacitor C1 in the charge-discharge module (1) may be replaced by an adjustable discharge resistor Rw1, an adjustable charge-discharge resistor Rw2, or an adjustable charge-discharge capacitor Cw 1; the bias resistor Rw3, the reference resistor Rrefw1 or the reference resistor Rrefw2 in the reference module (2) can be replaced by an adjustable bias resistor Rw3, an adjustable reference resistor Rrefw1 or an adjustable reference resistor Rrefw 2.
Referring to fig. 4, which is a fourth exemplary schematic diagram of a forward-reverse switching circuit formed by an operational amplifier according to the present invention, in fig. 1, the dc current source a1 in the reference module (2) is replaced by a dc voltage source V1, the negative terminal of the dc voltage source is connected to the ground, and the positive terminal of the dc voltage source is connected to one end of a bias resistor R3.
As shown in fig. 5, for a fifth exemplary schematic diagram of a circuit of forward-reverse switching composed of an operational amplifier according to the present invention, on the basis of fig. 1, the reference resistor Rref2 in the reference module (2) is replaced by a reference resistor Rref2, reference resistors Rref3, …, and a reference resistor Rrefn composed of several resistor strings, where n ≧ 3, and the resulting connection points are correspondingly set as a Vref2 terminal, a Vref3 terminal, a … terminal, and a Vrefn terminal; correspondingly, the operational amplifier U2 in the operational amplifier module (3) is also replaced by an operational amplifier U2, operational amplifiers U3 and … and an operational amplifier Un, in addition, the inverting terminal of the operational amplifier U2 is correspondingly connected to a Vref2 terminal, the inverting terminal of the operational amplifier U3 is correspondingly connected to a Vref3 terminal and …, and the inverting terminal of the operational amplifier Un is correspondingly connected to a Vrefn terminal; meanwhile, the in-phase terminals of all the operational amplifiers are connected with the Tcom terminal; finally, the output terminal OUT2 is set to the output terminal OUT2, the output terminals OUT3, …, and the output terminal OUTn, respectively.
As shown in fig. 6, which is a sixth exemplary schematic diagram of a forward-reverse switching circuit formed by an operational amplifier according to the present invention, on the basis of fig. 1, a charge-discharge module (1) and a reference module (2) are kept unchanged, a non-inverting terminal of an operational amplifier U1 is correspondingly connected to a Vref1 terminal, a non-inverting terminal of an operational amplifier U2 is correspondingly connected to a Vref2 terminal, …, and a non-inverting terminal of an operational amplifier Un is correspondingly connected to a Vrefn terminal; the inverting terminals of all the operational amplifiers are connected with the Tcom terminal, wherein n is more than or equal to 2; compared with the positive logic control, the negative logic control can be realized, namely low-level switching-on and high-level switching-off.
As shown in fig. 7, in an embodiment of a forward-reverse switching circuit formed by an operational amplifier according to the present invention, as can be seen from fig. 1, two loads connected in series, namely, a current-limiting resistor R8 and a light-emitting diode LED1, a current-limiting resistor R9 and a light-emitting diode LED2, are respectively connected between an output terminal OUT1 and a power ground and between an output terminal OUT2 and the power ground in an operational amplifier module (3), and the on and off operating states are indicated by displaying high and low levels;
in a positive logic sequential on state, the single-pole double-throw switch S1 is thrown to the end b, the charging loop transmits voltage to the in-phase end of an operational amplifier in the operational amplifier module (3), meanwhile, the Tcom end potential gradually rises, the constant reference voltage loop generates voltage and transmits the voltage to the reverse end of the operational amplifier in the operational amplifier module, when the in-phase end voltage of the operational amplifier is higher than the voltage of the Vref1 end, the operational amplifier U1 preferentially outputs high level to the current-limiting resistor R8 and the LED1, and the LED1 is bright; then the voltage of the non-inverting terminal of the operational amplifier is higher than the voltage of the Vref2 terminal, the operational amplifier U2 outputs high level to the current limiting resistor R9 and the light emitting diode LED2 later than the operational amplifier U1, the light emitting diode LED2 is on, and the sequential turn-on of positive logic is realized;
in a positive logic reverse order turn-off state, the single-pole double-throw switch S1 is thrown to the end a, an operational amplifier in the operational amplifier module (3) discharges through a discharge loop, meanwhile, the potential of a Tcom end gradually drops, a constant reference voltage loop generates voltage and transmits the voltage to the inverting end of the operational amplifier in the operational module, wherein the voltage of a Vref1 end is smaller than the voltage of a Vref2 end, when the voltage of the inverting end of the operational amplifier is lower than the voltage of the Vref2 end in the reference module (2), the operational amplifier U2 preferentially outputs low level to a current-limiting resistor R9 and a light-emitting diode LED2, and the light-emitting diode LED2 is extinguished; then the non-inverting terminal voltage of the operational amplifier is lower than the voltage of the Vref1 terminal, the operational amplifier U1 outputs low level to the current limiting resistor R8 and the LED1 later than the operational amplifier U2, the LED1 is extinguished, and the reverse order turn-off of the positive logic is realized.
As shown in fig. 8, another embodiment of the forward-reverse switching circuit formed by operational amplifiers according to the present invention operates substantially the same as the embodiment of fig. 7, except that two sets of operational amplifiers, i.e., operational amplifier U3 and operational amplifier U4, are added to the operational amplifier module (3), two sets of reference resistors, i.e., reference resistor Rref3 and reference resistor Rref4, are added to the reference module (2), and two sets of series loads, i.e., current-limiting resistor R10, light-emitting diode LED3, current-limiting resistor R11, and light-emitting diode LED4, are added to the output terminal;
the positive logic sequence opening process, the single-pole double-throw switch S1 is thrown to the b end, and the turn-on sequence of the light-emitting diodes is as follows: light emitting diode LED1, light emitting diode LED2, light emitting diode LED3, light emitting diode LED 4;
the positive logic reverse turn-off process, the single-pole double-throw switch S1 is thrown to the end a, and the sequence of the light-emitting diodes is as follows: light emitting diode LED4, light emitting diode LED3, light emitting diode LED2, light emitting diode LED 1.