CN218733875U - Communication control circuit and electric tool - Google Patents

Abstract

The utility model belongs to the technical field of communication control, concretely relates to communication control circuit, include: the device comprises a first signal transmission module, a voltage-controlled switch module and a second signal transmission module; the input end of the first signal transmission module is connected with a battery pack communication port of the electric tool, and the output end of the first signal transmission module is connected with the control end of the voltage-controlled switch module and used for transmitting a level signal output by a battery pack to the voltage-controlled switch module; the output end of the voltage-controlled switch module is connected with a control module of the electric tool; the input end of the second signal transmission module is connected with the control module, and the output end of the second signal transmission module is connected with the communication port of the battery pack and used for transmitting the level signal output by the control module to the communication port of the battery pack. The utility model discloses to the too high problem of low level in opto-coupler transmission time delay problem among the prior art and the transmission signal, add a voltage-controlled switch module at the opto-coupler output to reduce the transmission signal distortion.

Description

Communication control circuit and electric tool

Technical Field

The utility model belongs to the technical field of communication control, concretely relates to communication control circuit and electric tool.

Background

At present, in the design of PCB hardware, an optical coupler device is generally adopted for isolation to transmit communication signals in a communication circuit of the double-package series connection gardening tool or electric tool, an input signal Vin of a battery package COM bus is connected to a primary side of the optical coupler and is applied to a light emitting diode and a primary side resistor of the primary side, input current If of the optical coupler is generated and drives the light emitting diode, so that a phototriode of a secondary side is conducted, a loop VCC (5V) and a secondary side resistor generate Ic, the Ic generates Vout through the secondary side and transmits the Vout to an MCU (microprogrammed control unit), and the purpose of transmitting signals is achieved. However, this solution has two drawbacks, the first: the input and output delay has a problem of 20-30us, which causes the misjudgment of the communication level, i.e. the communication represents logic 0 (i.e. low level) and logic 1 (i.e. high level) by the time width of the low level, and the logic 0 defines: low level 50-150us, logic 1 defines: the low level is 150-250us, meanwhile, the logic 0 signal sent by the battery pack has the width of 100-130us, if the optical coupler has 20-30us delay, the logic 0 signal received by the MCU on the tool board is 150-160us, and the MCU is regarded as a logic 1 signal at this time, which is the reason of misjudgment caused by overlarge optical coupler delay. The second drawback is that: the low level of the COM or RX signal is raised to 1.26V-1.82V, which defines: less than 0.2 vcc (i.e., less than 1V), the low level is misjudged due to the low level exceeding 1V, and the problem of shutdown caused by communication error is also caused. The problem of optical coupling transmission delay relates to two parameters: the opto-coupler switches on time delay and opto-coupler turn-off time delay, because the time delay parameter of opto-coupler receives other factors to influence more, receives the temperature influence: the switch delay will increase with increasing temperature. Influenced by the size of the primary If: if is increased, turn-off delay is reduced, and turn-on delay is increased. Influenced by the size of the secondary Ic: RL (i.e., R108) decreases and the turn-on delay increases significantly. Therefore, in order to ensure the accuracy of switching on and off of the switching device, each path of input and output parameters are subjected to compromise to obtain proper values, which are contradictory to each other, but the sensitivity of the optical coupling circuit to the operation parameters is often difficult to be well made, and each electronic element has tolerance, including the optical coupling device, which is not beneficial to the stable work of the circuit, so that the problems of delay of transmission signals or raising of low level can be caused.

Aiming at the technical problems, a solution is also provided, namely the high-speed optical coupler is adopted for realizing the technical problems, but the high-speed optical coupler is expensive, so that the design cost is increased.

SUMMERY OF THE UTILITY MODEL

In view of the above shortcoming of the prior art, the utility model aims at providing a can solve opto-coupler transmission time delay problem and reduce the too high communication control circuit of low level in the transmission signal.

To achieve the above and other related objects, the present invention provides a communication control circuit, including: the device comprises a first signal transmission module, a voltage-controlled switch module and a second signal transmission module; the input end of the first signal transmission module is connected with a battery pack communication port of the electric tool, and the output end of the first signal transmission module is connected with the control end of the voltage-controlled switch module and used for transmitting a level signal output by a battery pack to the voltage-controlled switch module; the output end of the voltage-controlled switch module is connected with a control module of the electric tool; the input end of the second signal transmission module is connected with the control module, and the output end of the second signal transmission module is connected with the communication port of the battery pack and used for transmitting the level signal output by the control module to the communication port of the battery pack.

According to a specific embodiment of the present invention, when the battery pack transmits the level signal a, the control module receives the level signal a' within the time T1.

According to a specific embodiment of the present invention, when the level signal a is a low level and the logic is 0, the control module receives the level signal a' less than 1V within the T1 time; when the level signal a is at a high level and the logic is 1, the control module receives a level signal a' which is greater than 1V within the time T1; wherein T1 is less than 10us.

According to the utility model discloses a specific embodiment, first signal transmission module includes: a first optical coupler; the emitting end anode of the first optical coupler is connected with a power supply, and the cathode of the first optical coupler is connected with a COM interface of the battery pack; and a receiving end collector of the first optical coupler is connected with a power supply, and a receiving end emitter is used as an output end of the first signal transmission module and is connected with a control end of the voltage-controlled switch module.

According to a specific embodiment of the present invention, the first signal transmission module further comprises a first resistor and a second resistor; the first resistor is connected between the positive electrode of the transmitting end of the first optical coupler and a power supply; the second resistor is connected between the receiving end collector of the first optical coupler and a power supply.

According to the utility model discloses a specific embodiment, voltage-controlled switch module includes: the third resistor, the fourth resistor, the fifth resistor and the field effect transistor or the IGBT tube; the drain electrode of the field effect tube or the IGBT tube is respectively connected with a power supply and the control module; the third resistor is connected between the drain electrode of the field effect transistor or the IGBT and a power supply; the grid is used as a control end and is connected with the output end of the first signal transmission module through the fourth resistor; the source electrode is grounded, and a fifth resistor is connected between the source electrode and the grid electrode.

According to the utility model discloses a concrete embodiment, second signal transmission module includes: a sixth resistor, a second optocoupler, and a seventh resistor; the positive electrode of the transmitting end of the second optical coupler is connected with the sixth resistor in series and is connected with the power supply, the negative electrode of the transmitting end of the second optical coupler is connected with the control module, the collector of the receiving end of the second optical coupler is connected with the seventh resistor in series and is connected with the power supply, the emitter of the receiving end of the second optical coupler is connected with the shell of the electric tool, and the collector is used as the output end of the second signal transmission module.

According to a specific embodiment of the present invention, a first diode is disposed between the anode of the transmitting end of the first optical coupler and the collector of the receiving end of the second optical coupler; and the conduction direction of the first diode is that the anode of the transmitting end of the first optical coupler is unidirectionally conducted to the collector of the receiving end of the second optical coupler.

According to a specific embodiment of the present invention, a second diode is disposed between the COM interface of the battery pack and the receiving-end collector of the second optical coupler; and the conduction direction of the second diode is that the COM interface of the battery pack unit is unidirectionally conducted to the receiving end collector of the second optocoupler.

A power tool, comprising: a battery pack electrically connected to the power tool; wherein, electric tool is equipped with communication control circuit, communication control circuit includes: the device comprises a first signal transmission module, a voltage-controlled switch module and a second signal transmission module; the input end of the first signal transmission module is connected with a battery pack communication port of the electric tool, and the output end of the first signal transmission module is connected with the control end of the voltage-controlled switch module and used for transmitting a level signal output by a battery pack to the voltage-controlled switch module; the output end of the voltage-controlled switch module is connected with a control module of the electric tool; the input end of the second signal transmission module is connected with the control module, and the output end of the second signal transmission module is connected with the communication port of the battery pack and used for transmitting the level signal output by the control module to the communication port of the battery pack.

The technical effect of the utility model lies in, the utility model discloses an increase MOS pipe control circuit or IGBT pipe control circuit at the receiving terminal of optical coupler, change current control into voltage control, effectively solved signal transmission's time delay and the too high problem of low level signal, more be favorable to signal transmission's accuracy control.

Drawings

Fig. 1 is a diagram illustrating an embodiment of a communication control circuit applied to an electric tool according to the present invention;

fig. 2 is a block diagram of a communication control circuit according to an embodiment of the present invention;

fig. 3 is a communication control circuit according to an embodiment of the present invention;

fig. 4 is a waveform diagram of an input signal and a feedback signal of a communication control circuit according to an embodiment of the present invention.

Detailed Description

The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will be readily apparent to those skilled in the art from the disclosure herein. The present invention can also be implemented or applied through other different specific embodiments, and various details in the present specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the features in the following embodiments and examples may be combined with each other without conflict.

It should be noted that the drawings provided in the following embodiments are only for illustrating the basic idea of the present invention, and the drawings only show the components related to the present invention rather than being drawn according to the number, shape and size of the components in actual implementation, and the form, amount and ratio of the components in actual implementation may be changed arbitrarily, and the layout of the components may be more complicated.

The utility model discloses what describe is communication protocol between battery package and the tool control board, and data information is initiatively sent to the battery package, and data information is accepted to the tool control board. The BMS (Battery Management System) in the Battery pack is responsible for collecting and recording data, and the tool control board processes data information collected by the BMS and responds and transmits back the data information. For the problem of the time delay among the solution signal transmission and the too high problem of low level, the utility model provides a novel communication control circuit.

Referring to fig. 1-3, a communication control circuit for a garden power tool includes: a first signal transmission module 10, a voltage-controlled switch module 20 and a second signal transmission module 30; the input end of the first signal transmission module 10 is connected to a communication port of a battery pack 40 of an electric tool, and the output end of the first signal transmission module is connected to the control end of the voltage-controlled switch module 20, so as to transmit a level signal output by the battery pack 40 to the voltage-controlled switch module 20; the output end of the voltage-controlled switch module 20 is connected with the control module 50 of the electric tool, and is used for transmitting the level signal transmitted by the first signal transmission module 10 to the control module 50; wherein, the control module 50 is an MCU control chip. The input end of the second signal transmission module 30 is connected to the control module 50, and the output end is connected to the communication port of the battery pack 40, so as to transmit the level signal output by the control module to the communication port of the battery pack.

In one embodiment, the level signal transmitted by the battery pack 40 includes: the temperature value, the voltage value, the battery cell combination and the discharge state of the battery cell in the battery pack.

Preferably, the first signal transmission module 20 includes: a first optical coupler U1; the anode of the transmitting end of the first optical coupler U1 is connected with a power supply, and the cathode of the transmitting end of the first optical coupler U1 is connected with a COM interface of the battery pack; and a receiving end collector of the first optical coupler U1 is connected with a power supply, and a receiving end emitter is used as an output end of the first signal transmission module and is connected with a control end of the voltage-controlled switch module.

Opto-coupler elements (Opto-isolators, or optical couplers, abbreviated as OCs), also known as optocouplers or optoisolators and Opto-isolators, abbreviated as optocouplers. The photoelectric coupling element is a set of devices for transmitting electric signals by using light as a medium, and has the function of maintaining good isolation between input and output of the electric signals at ordinary times and enabling the electric signals to pass through the isolation layer in a transmission mode when necessary.

The photoelectric coupling element can transmit signals between two circuits which are not in common with the ground, and the two circuits cannot be influenced even if high voltage exists between the two circuits. The withstand voltage of the input to the output of a commercial photoelectric coupling element can reach 10kV, and the voltage change rate can be as fast as 10 kV/mu s.

The photoelectric coupling element can be divided into analog and digital elements, and is composed of a light emitter and a light detector. The light emitter and light detector are typically integrated into the same package, but there is no electrical or physical connection between them other than the light beam.

A common photocoupler is a Light Emitting Diode (LED) and a phototransistor (LED) in an opaque package. Other combinations are LED-photodiode, LED-LASCR and bulb-photoresistor. The photoelectric coupling element generally transmits digital signals, but in cooperation with some technologies, the photoelectric coupling element may also transmit analog signals.

The photoelectric coupling element is widely used in electrical isolation, level conversion, driving circuits and industrial communication, but has a weak Common-Mode Transient suppression (Common-Mode Immunity) capability due to a parasitic input-output capacitance problem, and further has problems in that its speed is limited, power consumption of the photoelectric coupling element is high, and the element is easily aged.

An optical coupler generally consists of three parts: light emission, light reception and signal amplification. The input electric signal drives the light emitting source to emit light, which is received by the light detector to generate a photocurrent, which is further amplified and then output. This completes the electro-optic-electric conversion, thereby playing the role of input, output and isolation. The input and the output of the optical coupler are isolated from each other, so that the optical coupler has good electrical insulation capability and interference resistance. And because the input end of the optical coupler belongs to a low-resistance element working in a current mode, the optical coupler has strong common-mode rejection capability. Therefore, it can be used as a terminal isolation device in long line transmission information to greatly improve the signal-to-noise ratio. The interface device used for signal isolation in computer digital communication and real-time control can greatly increase the reliability of its operation.

The light emitting source of the optical coupler is typically an infrared light emitting diode, which converts electrical energy into light of a specific wavelength, there is a closed optical channel (also called a dielectric channel) between the emitting source and the receiver, which is an optical sensor, which senses the light of the specific wavelength, and may be directly converted into electrical energy, or may modulate the current provided by the external power source by this signal. The receiver may be a photo resistor, a photodiode, a phototransistor, a Silicon Controlled Rectifier (SCR), or a TRIAC. Besides emitting light, the light emitting diode can also be used as a light sensing element, so that the light emitting diode can be used as the light sensing element, namely, the symmetrical bidirectional optical coupler. An optically coupled solid state relay in which a power switch is driven by an optocoupler having a photodiode, typically a pair of complementary MOSFETs. The slotted optical switch comprises a light emitting source and a receiver, but the light channel of the slotted optical switch is provided with an opening, and if other objects block the opening to prevent light from passing through, the signal generated by the receiver can be changed accordingly.

In a specific embodiment, the first signal transmission module 10 further includes a first resistor R1 and a second resistor R2; the first resistor R1 is connected between the positive electrode of the transmitting end of the first optocoupler U1 and a power supply; the second resistor R2 is connected between the receiving end collector of the first optocoupler U1 and a power supply.

Preferably, the voltage-controlled switching module 20 includes: a fourth resistor R4, a fifth resistor R5 and a field effect transistor or an IGBT (insulated gate bipolar transistor) Q1; the drain electrode of the field effect transistor or the IGBT transistor Q1 is respectively connected with a power supply and the control module; the grid is used as a control end and is connected with the output end of the first signal transmission module through the fourth resistor R4; the source electrode is grounded, and a fifth resistor R5 is connected between the source electrode and the grid electrode.

A Field Effect Transistor (Field Effect Transistor abbreviated FET) is abbreviated as a Field Effect Transistor. There are two main types: junction Field Effect Transistors (JFETs) and metal-oxide semiconductor field effect transistors (MOS-FETs). The majority carriers participate in the conduction, also known as unipolar transistors. It belongs to a voltage control type semiconductor device. The high-voltage power transistor has the advantages of high input resistance (107-1015 omega), low noise, low power consumption, large dynamic range, easiness in integration, no secondary breakdown phenomenon, wide safe working area and the like, and is a strong competitor of a bipolar transistor and a power transistor. A Field Effect Transistor (FET) is a semiconductor device that uses the electric field effect of a control input loop to control the output loop current and is named after this. It is also called a unipolar transistor because it conducts only by the majority carriers in the semiconductor.

The operating principle of the fet is, in short, that "ID flows through a channel between a drain and a source, and is controlled by a reverse-biased gate voltage formed by a pn junction between a gate and the channel". More precisely, the width of the ID flow path, i.e., the channel cross-sectional area, is controlled by the variation of reverse bias of the pn junction, resulting in the variation of the expansion of the depletion layer. In the non-saturated region of VGS =0, the transition layer is shown to be less extensive, and some electrons in the source region are pulled away by the drain, i.e. a current ID flows from the drain to the source, in response to the applied field of VDS between the drain and the source. The transition layer extending from the gate to the drain constitutes a portion of the channel in a blocking type, ID saturation. This state is referred to as pinch-off. This means that the transition layer blocks a part of the channel and the current is not switched off. Since the transition layer does not have free movement of electrons and holes, it ideally has almost insulating properties and is generally difficult for current to flow. But now the electric field between drain and source, actually two transition layers, in contact with the drain and near the lower portion of the gate, the high-speed electrons pulled away by the drift field pass through the transition layers. The saturation phenomenon of the ID occurs because the intensity of the drift electric field is almost constant. Next, VGS is changed in the negative direction so that VGS = VGS (off), and at this time, the transition layer is in a state of covering substantially the entire region. Moreover, the electric field of the VDS is mostly applied to the transition layer, pulling the electrons towards the electric field in the drift direction, only for a short part close to the source, which further disables the current flow.

In a specific embodiment, the voltage-controlled switch module further includes a third resistor R3; the third resistor R3 is connected between the drain electrode of the field effect transistor or the IGBT transistor Q1 and a power supply.

In a specific embodiment, the second signal transmission module 30 includes: a sixth resistor R6, a second optocoupler U2, and a seventh resistor R7; the emitting end anode of the second optical coupler U2 is connected with the sixth resistor R6 in series and is connected with a power supply, the emitting end cathode of the second optical coupler U2 is connected with the control module, the receiving end collector of the second optical coupler U2 is connected with the seventh resistor R7 in series and is connected with the power supply, the emitter of the second optical coupler U2 is connected with the shell of the electric tool, and the collector is used as the output end of the second signal transmission module.

In a specific embodiment, a first diode D1 is disposed between the anode of the transmitting end of the first optical coupler U1 and the collector of the receiving end of the second optical coupler U2; and the conducting direction of the first diode D1 is that the anode of the transmitting end of the first optical coupler U1 is unidirectionally conducted to the collector of the receiving end of the second optical coupler U2. A second diode D2 is arranged between the COM interface of the battery pack and the receiving end collector of the second optical coupler U2; the conduction direction of the second diode D2 is unidirectional conduction from the COM interface of the battery pack unit to the collector of the receiving end of the second optocoupler U2.

The utility model provides a pair of a specific embodiment's work flow as follows:

when the battery pack is inserted into the tool equipment, the tool control board firstly detects whether the voltage of the whole battery pack is larger than N x 3.0V (N is the number of battery pack electric cores). When the voltage is detected to be larger than N x 3.0V, the tool control board enters a discharging detection mode, and an internal circuit of the tool control board provides a +5V power supply to wake up the battery pack. And sending a level signal of the battery pack data information after the battery pack is awakened, wherein the level signal is sent to the cathode of the transmitting end of the first optical coupler through the COM interface of the battery pack. The level signal transmitted by the battery pack and the level signal fed back by the control module are both high and low level signal combinations.

When the COM interface of the battery pack transmits a logic 0 low level signal, the cathode of the transmitting end of the first optical coupler is at a low level, the anode of the transmitting end is provided with a +5V power supply, and the transmitting end of the first optical coupler forms a conducting loop. Therefore, the light emitting diode at the emitting end of the first optical coupler enables the phototriode at the receiving end to be conducted, at the moment, the receiving end forms a conducting loop, the grid electrode of the MOS tube is provided with starting voltage, and the drain electrode and the source electrode of the MOS tube are conducted. Because the source electrode of the MOS tube is grounded, and the MCU control chip of the tool control panel is connected to the drain electrode of the MOS tube, the MCU control chip is transmitted to be a low level signal.

When a COM interface of the battery pack transmits a logic 1 high-level signal, the cathode of the transmitting end of the first optical coupler is at a high level, the anode of the transmitting end is clamped by the first diode, the voltage of the anode of the transmitting end is smaller than the voltage of the cathode, the reverse bias is cut off, the transmitting end of the first optical coupler does not form a conducting loop, the light emitting diode of the transmitting end does not act, and the phototriode of the receiving end is turned off. Therefore, the gate of the MOS tube does not obtain a turn-on voltage, and the drain and the source are turned off. And the +5V power supply is conducted with the MCU control chip through the third resistor, and the MCU control chip acquires a high-level signal.

When the MCU control chip feeds back a logic 0 low level signal, the cathode of the transmitting end of the second optical coupler is a low level signal, the anode of the transmitting end is provided with a +5V power supply, and the transmitting end of the second optical coupler forms a conduction loop. Therefore, the light emitting diode at the emitting end of the second optical coupler enables the phototriode at the receiving end to be conducted, the receiving end forms a conducting loop, and the emitter of the receiving end is grounded. The battery pack acquires a low level signal through the second diode.

And when the MCU control chip feeds back a logic 1 high level signal, the transmitting end of the second optical coupler does not form a conducting loop. Therefore, the light emitting diode at the emitting end of the second optical coupler does not work, and the phototriode at the receiving end is turned off. The +5V power supply transmits a high-level signal to the COM interface of the battery pack through the first resistor and the light-emitting diode at the transmitting end of the first optical coupler.

Specifically, in the application, a communication circuit of a field effect transistor is not added, and the waveform of the input signal of the battery pack has a certain delay compared with the waveform of the feedback signal of the MCU control chip, so that the low-level voltage value is too high due to the delay, and the signal identification is wrong.

Referring to fig. 4, a waveform diagram of a communication control circuit provided in this embodiment is shown, where a waveform with a larger amplitude is a feedback signal change of an MCU control chip, and a waveform with a smaller amplitude is a battery pack input signal change; the input waveform is delayed by only 2us compared with the feedback waveform, the voltage value of the battery pack input signal is 640mv and does not exceed 1v; therefore, the embodiment well solves the problems of input signal delay and overhigh low level.

To sum up, the technical effect of the utility model is in, the utility model discloses an increase MOS pipe control circuit or IGBT pipe control circuit at the receiving terminal of optical coupler, change current control into voltage control, effectively solved signal transmission's time delay and the too high problem of low level signal, more be favorable to signal transmission's accuracy control.

The above embodiments are merely illustrative of the principles and effects of the present invention, and are not to be construed as limiting the invention. Modifications and variations can be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which may be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.

In the description herein, numerous specific details are provided, such as examples of components and/or methods, to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that an embodiment of the invention can be practiced without one or more of the specific details, or with other apparatus, systems, assemblies, methods, components, materials, parts, and/or the like. In other instances, well-known structures, materials, or operations are not specifically shown or described in detail to avoid obscuring aspects of embodiments of the present invention.

Reference throughout this specification to "one embodiment," "an embodiment," or "particular embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention, and not necessarily in all embodiments. Thus, appearances of the phrases "in one embodiment," "in an embodiment," or "in a specific embodiment" in various places throughout this specification are not necessarily referring to the same embodiment. Furthermore, the particular features, structures, or characteristics of any specific embodiment of the present invention may be combined in any suitable manner with one or more other embodiments. It is to be understood that other variations and modifications of the embodiments of the invention described and illustrated herein are possible in light of the teachings herein and are to be considered as part of the spirit and scope of the present invention.

It will also be appreciated that one or more of the elements shown in the figures can also be implemented in a more separated or integrated manner, or even removed for inoperability in some circumstances or provided for usefulness in accordance with a particular application.

Additionally, any reference arrows in the drawings/figures should be considered only as exemplary, and not limiting, unless otherwise expressly specified. Further, as used herein, the term "or" is generally intended to mean "and/or" unless otherwise indicated. Combinations of components or steps will also be considered as being noted where terminology is foreseen as rendering the ability to separate or combine is unclear.

As used in the description herein and throughout the claims that follow, "a," "an," and "the" include plural references unless otherwise indicated. Also, as used in the description herein and throughout the claims that follow, the meaning of "in \8230; includes" in 8230; and "on \8230; unless otherwise indicated.

The above description of illustrated embodiments of the invention, including what is described in the abstract of the specification, is not intended to be exhaustive or to limit the invention to the precise forms disclosed herein. While specific embodiments of, and examples for, the invention are described herein for illustrative purposes only, various equivalent modifications are possible within the spirit and scope of the present invention, as those skilled in the relevant art will recognize and appreciate. As noted, these modifications may be made to the present invention in light of the foregoing description of illustrated embodiments of the invention and are to be included within the spirit and scope of the present invention.

The system and method have been described herein in general terms as providing details to facilitate the understanding of the invention. Furthermore, various specific details have been given to provide a general understanding of the embodiments of the invention. One skilled in the relevant art will recognize, however, that an embodiment of the invention can be practiced without one or more of the specific details, or with other apparatus, systems, assemblies, methods, components, materials, parts, and/or the like. In other instances, well-known structures, materials, and/or operations are not specifically shown or described in detail to avoid obscuring aspects of embodiments of the invention.

Thus, although the present invention has been described herein with reference to particular embodiments thereof, freedom of modification, various changes and substitutions are also within the foregoing disclosure, and it should be understood that in some instances some features of the present invention will be employed without a corresponding use of other features without departing from the scope and spirit of the present invention as set forth. Accordingly, many modifications may be made to adapt a particular situation or material to the essential scope and spirit of the present invention. It is intended that the invention not be limited to the particular terms used in following claims and/or to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include any and all embodiments and equivalents falling within the scope of the appended claims. Accordingly, the scope of the invention is to be determined solely by the appended claims.

Claims (10)

1. A communication control circuit, comprising: the device comprises a first signal transmission module, a voltage-controlled switch module and a second signal transmission module;

the input end of the first signal transmission module is connected with a battery pack communication port of the electric tool, and the output end of the first signal transmission module is connected with the control end of the voltage-controlled switch module and used for transmitting a level signal output by a battery pack to the voltage-controlled switch module;

the output end of the voltage-controlled switch module is connected with a control module of the electric tool;

the input end of the second signal transmission module is connected with the control module, and the output end of the second signal transmission module is connected with the communication port of the battery pack and used for transmitting the level signal output by the control module to the communication port of the battery pack.

2. The communication control circuit according to claim 1, wherein the control module receives the level signal a' within a time T1 when the battery pack transmits the level signal a.

3. The communication control circuit according to claim 2, wherein when the level signal a is low and logic is 0, the control module receives a level signal a' less than 1V within a time T1; when the level signal a is at a high level and the logic is 1, the control module receives a level signal a' which is greater than 1V within the time T1; wherein T1 is less than 10us.

4. The communication control circuit of claim 1, wherein the first signal transmission module comprises: a first optical coupler; the emitting end anode of the first optical coupler is connected with a power supply, and the cathode of the first optical coupler is connected with a COM interface of the battery pack; and a receiving end collector of the first optical coupler is connected with a power supply, and a receiving end emitter is used as an output end of the first signal transmission module and is connected with a control end of the voltage-controlled switch module.

5. The communication control circuit of claim 4, wherein the first signal transmission module further comprises a first resistor and a second resistor;

the first resistor is connected between the positive electrode of the transmitting end of the first optical coupler and a power supply;

the second resistor is connected between the receiving end collector of the first optical coupler and a power supply.

6. The communication control circuit of claim 1, wherein the voltage controlled switch module comprises: the third resistor, the fourth resistor, the fifth resistor and the field effect transistor or the IGBT tube; the drain electrode of the field effect tube or the IGBT tube is respectively connected with a power supply and the control module; the third resistor is connected between the drain electrode of the field effect transistor or the IGBT and a power supply; the grid is used as a control end and is connected with the output end of the first signal transmission module through the fourth resistor; the source electrode is grounded, and a fifth resistor is connected between the source electrode and the grid electrode.

7. The communication control circuit of claim 4, wherein the second signal transmission module comprises: a sixth resistor, a second optocoupler, and a seventh resistor; the emitting end anode of the second optical coupler is connected with the sixth resistor in series and is connected with the power supply, the emitting end cathode of the second optical coupler is connected with the control module, the receiving end collector of the second optical coupler is connected with the seventh resistor in series and is connected with the power supply, the receiving end emitter of the second optical coupler is connected with the shell of the electric tool, and the collector is used as the output end of the second signal transmission module.

8. The communication control circuit of claim 7, wherein a first diode is disposed between the anode of the transmitting terminal of the first optical coupler and the collector of the receiving terminal of the second optical coupler; and the conduction direction of the first diode is that the anode of the transmitting end of the first optical coupler is unidirectionally conducted to the collector of the receiving end of the second optical coupler.

9. The communication control circuit according to claim 7, wherein a second diode is provided between the COM interface of the battery pack and the receiving-end collector of the second optocoupler; and the conduction direction of the second diode is that the collector electrode of the receiving end of the second optocoupler is unidirectionally conducted from the COM interface of the battery pack unit.

10. An electric power tool, characterized by comprising:

a battery pack electrically connected to the power tool;

wherein, electric tool is equipped with communication control circuit, communication control circuit includes: the device comprises a first signal transmission module, a voltage-controlled switch module and a second signal transmission module;

the input end of the first signal transmission module is connected with a battery pack communication port of the electric tool, and the output end of the first signal transmission module is connected with the control end of the voltage-controlled switch module and used for transmitting a level signal output by a battery pack to the voltage-controlled switch module;

the output end of the voltage-controlled switch module is connected with a control module of the electric tool;

the input end of the second signal transmission module is connected with the control module, and the output end of the second signal transmission module is connected with the communication port of the battery pack and used for transmitting the level signal output by the control module to the communication port of the battery pack.

Images