CN211908765U

CN211908765U - Protection starting power cut circuit composed of D triggers

Info

Publication number: CN211908765U
Application number: CN202020826569.4U
Authority: CN
Inventors: 廖无限; 朱亮; 王鸿儒; 谢振球; 张阳; 谌淼军; 徐彬鑫; 刘贺
Original assignee: Hunan University of Technology
Current assignee: Hunan University of Technology
Priority date: 2020-05-18
Filing date: 2020-05-18
Publication date: 2020-11-10
Anticipated expiration: 2030-05-18

Abstract

The invention discloses a protection starting circuit consisting of D triggers, which comprises a preset button S1, a preset button S2, an output end Uout and a D trigger module; the preset button S1 is a normally open button and is used for providing an input control signal for starting or stopping; the preset button S2 is a normally open button and is used for providing input control signals for stopping or starting; the D trigger module comprises an equivalent D trigger circuit and a conversion circuit for presetting positive logic control output and negative logic control output; the D flip-flop module receives the input control signals provided by the preset button S1 and preset button S2 and generates corresponding start, hold or stop control signals to the output Uout for transmission, driving or indication to the next stage circuit. The power-on/off circuit composed of the D flip-flops provided by the invention not only has the performances of simple structure, low cost and strong universality, but also can meet the requirements of a positive logic output control mode and a negative logic output control mode.

Description

Protection starting power cut circuit composed of D triggers

Technical Field

The invention relates to the field of electrical control, in particular to a power-on/power-off circuit composed of D triggers.

Background

In the field of electrical control, a basic control circuit capable of realizing starting, holding (self-locking) and stopping functions is usually called as a power-on/off circuit for short, and is provided with an obvious starting and stopping button which is beneficial to operation and used for connecting and disconnecting the controlled circuit, and the circuit has a memory holding function of 'power-off volatility and power-on non-volatility' like a ROM (read only memory) applied to a computer, namely the controlled circuit can be automatically disconnected after the power is lost, the operation needs to be realized by manual priority intervention again after the power is restored, and the starting working state of the power can be kept by 'memory' after the starting button is pressed; at the moment, after the stop button is pressed again, the power-off stop working state can be kept in a 'memory' state; due to the advantages of such reliable safety, the method has been widely used by the majority of manufacturers from birth.

The start-up and protection circuit comprises a positive logic output control mode and a negative logic output control mode, and the output results of the two modes are completely different.

(1) Positive logic output control: when a start button is pressed, the control circuit outputs an H level; pressing a stop button, and outputting an L level by a control circuit;

(2) negative logic output control: pressing a starting button, and outputting an L level by a control circuit; the stop button is pressed and the circuit outputs an H level.

The inventor discovers that in the process of implementing the embodiment of the invention:

the proportion occupied by adopting a single positive logic output control mode in the start-up and shutdown circuit at the present stage is higher, if a negative logic output control mode is adopted, two options are generally available, wherein the first option is to redesign a single negative logic output control circuit, and the second option is to specially add a more complex negative logic conversion circuit on the basis of the original positive logic output control circuit; therefore, under the situation that the current market demand is changeable, a power protection circuit is lacked in the field of electrical control, the power protection circuit not only has the function of conveniently converting a positive logic output control mode and a negative logic output control mode, but also has the performances of simple structure, low cost and strong universality.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a start-up and shutdown circuit consisting of D flip-flops.

The technical scheme adopted by the invention is as follows:

the system comprises a preset button S1, a preset button S2, an output end Uout and a D trigger module;

the preset button S1 is a normally open button and is used for providing an input control signal for starting or stopping; the preset button S2 is a normally open button and is used for providing input control signals for stopping or starting;

the D trigger module comprises an equivalent D trigger circuit and a conversion circuit for presetting positive logic control output and negative logic control output; the D trigger module receives input control signals provided by the preset button S1 and the preset button S2 and generates corresponding starting, keeping or stopping control signals to the output end Uout for transmitting, driving or indicating to a next-stage circuit;

the preset button S1 and the preset button S2 have different functions, the sequence of the preset button S1 and the preset button S2 can only be one of starting and stopping, stopping and starting configuration combinations, and finally the determination of specific functions is influenced by the equivalent D flip-flop circuit initial state, the preset positive logic control output and the conversion circuit of the negative logic control output.

Further, the D flip-flop module mainly includes a D flip-flop U1, a pull-down resistor R1, a current-limiting resistor R2, a pull-up resistor R3, a current-limiting resistor R4, and a pull-up resistor R5;

the conversion circuit for presetting the positive logic control output and the negative logic control output comprises a preset resistor R6 and a preset resistor R7;

one end of the preset button S1 is connected with a direct current power supply VCC, the other end of the preset button S1 is respectively connected with one end of a current-limiting resistor R2 and one end of a pull-down resistor R1, the other end of the pull-down resistor R1 is connected with a direct current power supply GND, and the other end of the current-limiting resistor R2 is connected with a pin CLK of a D trigger U1 for providing a starting or stopping control signal;

one end of the preset button S2 is connected with a direct current power supply GND, the other end of the preset button S2 is respectively connected with one end of a pull-up resistor R5 and one end of a current-limiting resistor R4, and the other end of the current-limiting resistor R4 is connected with a pin of a D flip-flop U1

The pull-up resistor R5 is used for providing a stop or start control signal, and the other end of the pull-up resistor R5 is connected with a direct current power supply VCC;

with the D trigger U1 as the center, its pin VCC is connected with DC power supply VCC, pin GND is connected with DC power supply GND, and pin D is connected with pin GND respectively

One end of a pull-up resistor R3, the other end of the pull-up resistor R3 is connected with a direct current power supply VCC, and a pin

One end of a preset resistor R6 is connected, the pin Q is connected with one end of a preset resistor R7, and the other end of the preset resistor R6 is respectively connected with the other end of the preset resistor R7 and the output end Uout;

the preset resistor R6 and the preset resistor R7 are used in pairs in the application circuit, where one preset value is 0 ohm, which is equivalent to a short circuit, and the other preset value is infinity, which is equivalent to an open circuit.

Further, when one of the preset resistor R6 and the preset resistor R7 is less than or equal to 2 kohms, the other preset resistor R6 and the preset resistor R7 are greater than or equal to 100 kohms.

Further, the preset resistor R6 and the preset resistor R7 are replaced by a single-pole double-throw switch S3, a branch switch pin of the single-pole double-throw switch S3 is connected to the pin Q of the D flip-flop U1, and the other branch switch pin is connected to the pin Q of the D flip-flop U1

The common pin of which is connected to said output Uout.

The invention has the advantages that the provided scheme for starting the power-on/power-off circuit composed of the D trigger not only inherits the advantages of safety and reliability of the prior art, but also has the performances of simple structure, low cost and strong universality, and can meet the requirements of a positive logic output control mode and a negative logic output control mode.

Drawings

FIG. 1 is a typical diagram of a power-on/power-off circuit composed of D flip-flops according to the present invention.

FIG. 2 shows an embodiment of an attack protection circuit comprising D flip-flops according to the present invention.

Fig. 3 is a selected D flip-flop truth table.

Fig. 4 is a table showing the specific arrangement of the preset resistor R7, the preset resistor R6, the preset button S1 and the preset button S2.

FIG. 5 shows another embodiment of an attack protection circuit comprising D flip-flops according to the present invention.

Fig. 6 is a table showing the specific configuration of the single pole double throw switch S3, pin Q and output Uout, preset button S1 and preset button S2.

FIG. 7 shows an embodiment of an attack protection circuit composed of D flip-flops according to the present invention.

FIG. 8 is another embodiment of an attack/hold circuit comprising D flip-flops according to the present invention.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, specific embodiments thereof are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, but rather should be construed as broadly as the present invention is capable of modification in various respects, all without departing from the spirit and scope of the present invention.

Fig. 1 is a typical schematic diagram of a start-up and shutdown circuit composed of D flip-flops according to the present invention, which includes a preset button S1, a preset button S2, an output Uout, and a D flip-flop module;

As shown in fig. 2, an embodiment of a power-on/power-off circuit composed of D flip-flops according to the present invention includes a D flip-flop U1, a pull-down resistor R1, a current-limiting resistor R2, a pull-up resistor R3, a current-limiting resistor R4, and a pull-up resistor R5;

Referring to fig. 3, for the selected D flip-flop truth table, the specific application of the start-up and shutdown circuit composed of D flip-flops provided by the present invention is implemented based on the

states

2, 4 and 6 in the selected D flip-flop truth table, where the state 6 is the initial control state or the hold control state, the state 4 is the start control state or the stop control state, and the state 2 is the stop control state or the start control state.

As shown in fig. 4, a specific configuration table for the preset resistor R7, the preset resistor R6, the preset button S1 and the preset button S2 is obtained by comprehensively designing and summarizing the embodiment of fig. 2 and the D flip-flop truth table of fig. 3, and the specific use steps refer to the following steps:

step one, after power is off, a preset resistor R7 and a preset resistor R6 are idled or disconnected;

second, power-on test, which is to determine the Q of the D flip-flop by actually measuring according to the D flip-flop truth table of FIG. 3 and the hardware circuit of the embodiment of FIG. 2₀Terminal and

end initial state value, there are two possibilities, namely Q₀At H level and

at L level, or, Q₀At L level and

at the H level;

thirdly, according to the specific application requirements of the positive logic control output or the negative logic control output, the preset resistor R7, the preset resistor R6, the preset button S1 and the preset button S2 can be configured correspondingly with reference to fig. 4.

The configuration shown in fig. 4 has four configurations, and since the operation principle and the specific process of the configuration are similar, only one configuration example is used for illustration, and the other three configurations can easily obtain corresponding results according to the process and the principle of the example.

For example, after the first and second operation steps, if the Q of the D flip-flop is determined to be good₀Terminal and

end initial state is, Q₀At L level and

at H level, if the configuration is to be performed as a positive logic control output, the value of the preset resistor R7 is configured to be 0 ohm, which is equivalent to a short circuit, and the value of the preset resistor R6 is configured to be infinity, which is equivalent to an open circuit; the preset button S1 and the preset button S2 are configured as function buttons for start and stop, respectively;

now referring again to fig. 3, the working process of the D flip-flop truth table is:

(1) initial state, corresponding to state 6, Q₀At L level and

at the H level;

(2) start State, corresponding to State 4, preset button S1 is configured as a Start button, Q upon a single actuation, whenever a rising edge trigger is satisfied₀The voltage level is changed to be H level, namely the potential of the output end Uout is changed to be H level, so that the starting control function is realized;

(3) holding state, on the basis of the above-mentioned starting state, when any button is not actuated, the state returns to the state 6, only at this time Q₀It is changed to the H level and,

to L level, i.e. Q₀The terminal keeps keeping the H potential, namely the potential of the output terminal Uout is kept at the H level, thus realizing the function of 'memory' keeping control;

(4) stop state, preset button S2 is configured as stop function button, and on the basis of analyzing the above holding state, when preset button S2 is actuated, state 2 is entered, at which time Q is entered₀The voltage level of the output end Uout is changed to be L level, and the voltage level returns to the initial state, namely the voltage level of the output end Uout is changed to be low level, and the function of 'memorizing' stop control is realized.

Of course, in the above embodiment, when one of the preset values of the preset resistor R6 and the preset resistor R7 is less than or equal to 2 kohms, the other preset value is greater than or equal to 100 kohms, and the results are correspondingly similar after corresponding configuration and operation are performed based on the above principle and steps.

Referring to fig. 5, for another embodiment of the start-up and shutdown circuit composed of D flip-flops of the present invention, the preset resistor R6 and the preset resistor R7 are replaced by a single-pole double-throw switch S3, a branch switch pin of the single-pole double-throw switch S3 is connected to the pin Q of the D flip-flop U1, and another branch switch pin is connected to the pin Q of the D flip-flop U1

The common pin of which is connected to said output Uout.

Referring to fig. 6, a specific configuration table of the single-pole double-throw switch S3, the pin Q, the output Uout, the preset button S1, and the preset button S2 is an application table designed after summarizing the embodiment of fig. 5 and the truth table of the D flip-flop of fig. 3, and the operation principle, configuration steps, and operation process of the present invention are substantially similar to those of the above-mentioned embodiments, except that the single-pole double-throw switch S3 is used to replace the preset resistor R6 and the preset resistor R7, which is relatively more efficient.

Fig. 7 shows a specific example of a power-on/power-off circuit composed of D flip-flops according to the present invention, which works substantially the same as the previous embodiment, wherein the key components are: the D trigger is TC7W74F in model, a single-pole double-throw switch S3 in model SS12F44 in model, and in addition, a branch circuit formed by connecting a current-limiting resistor R8 and a light-emitting diode LED1 in series is externally connected to an output end Uout to a direct-current power supply GND for indicating the working state of a protection circuit; the initial state of the D flip-flop is Q₀At L level and

a branch switch of the single-pole double-throw switch S3 is connected with a Q pin of a D trigger, a preset button S1 is a starting button, a preset button S2 is configured as a stop function button, and after corresponding actions are carried out, namely when a light-emitting diode LED1 is lightened, the output end Uout is at an H level and indicates after starting; when the LED1 goes off, the output Uout is at L level, indicating the stop.

Referring to fig. 8, another embodiment of a start-up and power-down circuit composed of a D flip-flop of the present invention is different from the above embodiments in that a transistor Q1 is externally connected to the output terminal Uout to drive a switch circuit of a relay J1, wherein the transistor Q1 is S8050, the relay J1 is HF46-5-HS1, and a freewheeling diode D3 is 1N 4148; after the corresponding action, namely when the output end Uout is at a high level, the relay J1 executes a power-on action; when the output Uout is low, the relay J1 performs a power-off action.

Claims

1. A power-on/power-off circuit composed of D triggers is characterized by comprising a preset button S1, a preset button S2, an output end Uout and a D trigger module;

2. The power on/off circuit composed of D flip-flops according to claim 1, wherein the D flip-flop module mainly comprises a D flip-flop U1, a pull-down resistor R1, a current-limiting resistor R2, a pull-up resistor R3, a current-limiting resistor R4, and a pull-up resistor R5;

one end of the preset button S2 is connected with a DC power supply GND, and the other end is respectively connected with one end of a pull-up resistor R5 and a current-limiting resistorOne end of a resistor R4 and the other end of a current limiting resistor R4 are connected with a pin of a D flip-flop U1

3. The power-on/power-off circuit comprising a D flip-flop according to claim 2, wherein one of said preset resistors R6 and R7 is less than or equal to 2 kohms, and the other is greater than or equal to 100 kohms.

4. The protection circuit of claim 2, wherein the preset resistor R6 and the preset resistor R7 are replaced by a single-pole double-throw switch S3, a branch switch pin of the single-pole double-throw switch S3 is connected to the pin Q of the D flip-flop U1, another branch switch pin is connected to the pin Q of the D flip-flop U1, and the common pin of the branch switch is connected to the output Uout.