CN216560755U - Isolated voltage sampling circuit - Google Patents

Abstract

The present disclosure relates to an isolated voltage sampling circuit, comprising: a control module; the communication module is in communication connection with the control module and is used for communicating with external equipment; the voltage sampling module comprises an input multiplexer for providing multiple input channels and a plurality of first resistors for voltage division, the resistance values of the first resistors are different, each input channel is connected with at least one first resistor, and the multiple input channels are connected with an analog ground after being connected with the first resistors; the signal output end of the voltage sampling module is electrically connected with the signal input end of the control module; and the power supply module is respectively electrically connected with the control module and the voltage sampling module and used for supplying power. The multi-path voltage sampling circuit can sample multi-path voltages simultaneously, can sample voltages of a plurality of points simultaneously, can simplify a circuit structure, reduces circuit volume and cost, and can collect isolated voltages.

Description

Isolated voltage sampling circuit

Technical Field

The disclosure relates to the technical field of voltage sampling circuits, in particular to an isolated voltage sampling circuit.

Background

In recent years, with the deep popularization of energy-saving and emission-reducing concepts, batteries have been widely applied to various vehicles as power sources to reduce the usage amount of gasoline and reduce carbon emission. The battery protection board is an integrated circuit board for protecting charging and discharging of lithium battery, and generally includes control IC, MOS switch, precision resistor and auxiliary device NTC, ID memory, etc. In the production and the actual use of battery, need gather the voltage signal of battery protection shield to carry out processes such as voltage monitoring, undervoltage overvoltage protection.

The voltage sampling circuit of current battery protection shield owing to only have a voltage input channel, can only sample the voltage of a point on the circuit protection shield simultaneously usually, just need set up a plurality of voltage sampling circuit when need carry out voltage sampling to a plurality of points of circuit protection shield simultaneously like this, and this can cause circuit structure miscellaneous, increases circuit volume and cost, and isolation voltage still can't be gathered to current voltage sampling circuit simultaneously, has certain limitation.

SUMMERY OF THE UTILITY MODEL

In order to solve the problems existing in the prior art, the present disclosure is directed to an isolated voltage sampling circuit. The multi-path voltage sampling circuit can sample multi-path voltages simultaneously, can sample voltages of a plurality of points simultaneously, can simplify a circuit structure, reduces circuit volume and cost, and can collect isolated voltages.

The isolated voltage sampling circuit of the present disclosure includes:

a control module;

the communication module is in communication connection with the control module and is used for communicating with external equipment;

the voltage sampling module comprises an input multiplexer for providing multiple input channels and a plurality of first resistors for voltage division, the resistance values of the first resistors are different, each input channel is connected with at least one first resistor, and the multiple input channels are connected with an analog ground after being connected with the first resistors; the signal output end of the voltage sampling module is electrically connected with the signal input end of the control module;

and the power supply module is respectively electrically connected with the control module and the voltage sampling module and used for supplying power.

Preferably, the control module comprises an FM33 series MCU.

Preferably, the communication module includes:

an RS485 communication chip; the RS485 communication chip is in communication connection with the control module and is used for communicating with external equipment;

the communication isolation power supply is electrically connected with the RS485 communication chip and is used for supplying power to the RS485 communication chip.

Preferably, the voltage sampling module includes:

the device comprises an analog-to-digital conversion chip ADS1115, wherein four input channels of the analog-to-digital conversion chip ADS1115 are used for accessing four sampling voltages at most simultaneously; and the signal output end of the analog-to-digital conversion chip ADS1115 is electrically connected with the signal input end of the control module.

Preferably, the voltage sampling module further includes a voltage division filtering unit, and the voltage division filtering unit includes:

the second resistors are connected between the analog-to-digital conversion chip ADS1115 and the control module, and each input channel of the analog-to-digital conversion chip ADS1115 is connected to an analog ground through at least one second resistor;

the first capacitors are connected between the analog-to-digital conversion chip ADS1115 and the control module, and each input channel of the analog-to-digital conversion chip ADS1115 is connected to an analog ground through at least one first capacitor; and after the at least one second resistor is connected with the at least one first capacitor in parallel, one end of the at least one second resistor is connected with the single-path input channel, and the other end of the at least one second resistor is connected to the analog ground.

Preferably, the voltage sampling module further includes two differential filter units, each differential filter unit is electrically connected to two input channels of the analog-to-digital conversion chip ADS1115, each differential filter unit includes three second capacitors sequentially connected end to form a closed loop, one node of the differential filter unit is connected to an analog ground, one end of one of the second capacitors is electrically connected to one input channel of the analog-to-digital conversion chip ADS1115, and the other end of the one of the second capacitors is electrically connected to the other input channel of the analog-to-digital conversion chip ADS 1115.

Preferably, the power supply module comprises a DC isolated power supply chip B0515S.

Preferably, the power module further comprises a first voltage stabilizing unit and a second voltage stabilizing unit which are connected in parallel;

the voltage input end of the first voltage stabilizing unit is electrically connected with the voltage output end of the DC isolation power supply chip B0515S, and the voltage output end is electrically connected with the control module and used for supplying power to the control module;

and the voltage input end of the second voltage stabilizing unit is electrically connected with the voltage output end of the DC isolation power supply chip B0515S, and the voltage output end is electrically connected with the voltage sampling module and used for supplying power to the voltage sampling module.

Preferably, the first voltage stabilizing unit and the second voltage stabilizing unit are both linear voltage regulators (LDOs).

Preferably, the power supply module further includes:

and the voltage input end of the Buck voltage reduction unit is used for accessing external voltage, and the voltage output end of the Buck voltage reduction unit is electrically connected with the voltage input end of the DC isolation power supply chip B0515S.

The isolated voltage sampling circuit has the advantages that:

1. according to the circuit protection board, the input multiplexer with the multiple input channels is arranged, the multiple input channels can be provided, voltage sampling can be simultaneously carried out on multiple points of the circuit protection board through a single circuit, multiple voltage sampling circuits are not required to be arranged, the circuit structure can be simplified, and the circuit volume and the cost are reduced;

2. according to the voltage sampling device, the first resistor for voltage division is connected to each input channel, and the multiple input channels are connected to the analog ground after being connected to the first resistor, so that the voltage sampling module can sample voltages on different places, namely isolated voltages can be sampled, and actual sampling requirements can be better met;

3. according to the voltage sampling module, the first resistors with different resistance values are connected to the multiple input channels, so that the multiple input channels can adopt voltages with different sizes, the voltage sampling module has multiple gears, and a proper input channel can be selected for sampling according to the size of actual sampling voltage, so that the sampling process is more flexible; and through designing the resistance of first resistance, can make voltage sampling module's sampling range wide, the suitability is more extensive.

Drawings

Fig. 1 is a block diagram of an isolated voltage sampling circuit according to the present disclosure;

FIG. 2 is a schematic diagram of a circuit configuration of a control module according to the present disclosure;

fig. 3 is a schematic circuit structure diagram of the RS485 communication chip according to the present disclosure;

FIG. 4 is a schematic diagram of a circuit configuration of a communicatively isolated power supply according to the present disclosure;

FIG. 5 is a schematic circuit diagram of a voltage sampling module according to the present disclosure;

FIG. 6 is a schematic circuit diagram of a power module according to the present disclosure;

fig. 7 is a schematic circuit structure diagram of the Buck voltage reduction unit according to the present disclosure.

Description of reference numerals: the device comprises a control module, a communication module, a 3-voltage sampling module and a 4-power module.

Detailed Description

As shown in fig. 1 to 7, an isolated voltage sampling circuit according to the present disclosure includes:

and the control module 1 is used for processing and converting the sampled voltage signal.

And the communication module 2 is in communication connection with the control module 1 and is used for communicating with external equipment, such as an upper computer like a computer, so that the sampled voltage signal is output to the upper computer for the next operation.

The voltage sampling module 3, the voltage sampling module 3 is used for carrying out the voltage sampling. Referring to fig. 5 in detail, the voltage sampling module 3 includes an input multiplexer for providing multiple input channels, and a plurality of first resistors for voltage division, wherein the resistances of the plurality of first resistors are different, so that the voltage division effect of each first resistor is different, and each input channel can be used for sampling voltages with different magnitudes. Each path of input channel is connected with at least one first resistor, and the multiple paths of input channels are connected with the analog ground after being connected with the first resistor, so that the voltage sampling module 3 can adopt voltages connected on different grounds, and isolated voltages can be collected.

And the power module 4 is electrically connected with the control module 1 and the voltage sampling module 3 respectively for supplying power.

The working process of the isolated voltage sampling circuit is as follows, the input channel is respectively connected to the positions of voltage points to be adopted, the voltage at the positions of the voltage points is input into the input channel, the voltage is input into the control module 1 after the voltage division action of the voltage dividing resistor in the input channel, the control module 1 processes and converts the input voltage signal, and then the voltage signal is communicated with an upper computer such as a computer through the communication module 2, so that an operator can monitor the voltage at the positions of the voltage points in real time.

According to the circuit protection board, the input multiplexer with the multiple input channels is arranged, the multiple input channels can be provided, voltage sampling can be simultaneously carried out on multiple points of the circuit protection board through a single circuit, multiple voltage sampling circuits are not required to be arranged, the circuit structure can be simplified, and the circuit volume and the cost are reduced;

according to the voltage sampling device, the first resistor for voltage division is connected to each input channel, and the multiple input channels are connected to the analog ground after being connected to the first resistor, so that the voltage sampling module 3 can sample voltages on different places, namely isolated voltages can be sampled, and actual sampling requirements can be better met;

according to the voltage sampling device, the first resistors with different resistance values are connected to the multiple input channels, so that the multiple input channels can adopt voltages with different sizes, the voltage sampling module 3 has multiple gears, and a proper input channel can be selected for sampling according to the size of actual sampling voltage, so that the sampling process is more flexible; and through designing the resistance of first resistance, can make voltage sampling module 3's sampling range wide, the suitability is more extensive.

Further, in the embodiment, referring to fig. 2 in detail, the control module 1 includes an FM33 series MCU, and the pin wiring diagram of the FM33 series MCU is specifically shown in fig. 2.

Further, in the present embodiment, please refer to fig. 3 and fig. 4 in detail, the communication module 2 includes:

RS485 communication chip, RS485 communication chip and control module 1 communication connection for communicate with external device through the RS485 agreement, RS485 communication chip has transmission efficiency height, interference killing feature is strong, the stable advantage of transmission.

The circuit structure diagram of the communication isolation power supply is shown in fig. 4, and the communication isolation power supply is mainly used for providing a group of 5V isolation voltage for the RS485 communication chip, so that the RS485 communication chip can be powered by a single power supply to work and is not interfered.

Further, in this embodiment, referring to fig. 5 in detail, the voltage sampling module 3 includes:

the analog-to-digital conversion chip ADS1115 and the analog-to-digital conversion chip ADS1115 can convert analog signals into digital signals, voltage signals (analog signals) are input into the analog-to-digital conversion chip ADS1115 from an input channel, the digital signals are converted into the digital signals through AD conversion of the analog-to-digital conversion chip ADS1115, and then the digital signals are transmitted to the MCU through the I IC bus and processed by the MCU. The analog-to-digital conversion chip ADS1115 has four input channels, can sample four voltages at most simultaneously, and has the advantages of high conversion speed, low energy consumption and stable processing process.

Further, in this embodiment, please continue to participate in fig. 5, the voltage sampling module 3 further includes a voltage division filtering unit, and the voltage division filtering unit includes:

the second resistors are connected between the analog-to-digital conversion chip ADS1115 and the control module 1, and each input channel of the analog-to-digital conversion chip ADS1115 is connected to an analog ground through at least one second resistor;

the first capacitors are connected between the analog-to-digital conversion chip ADS1115 and the control module 1, and each input channel of the analog-to-digital conversion chip ADS1115 is connected to an analog ground through at least one first capacitor; for a single input channel, at least one second resistor and at least one first capacitor form a parallel connection structure, one end of the parallel connection structure is connected with the input channel, and the other end of the parallel connection structure is connected to the analog ground. After the voltage signal is input into the input channel, the voltage signal can be input into the analog-to-digital conversion chip ADS1115 after further voltage division of the second resistor and filtering action of the first capacitor, so that the input voltage signal has no clutter, and interference in the input voltage signal can be suppressed and prevented. In this embodiment, the voltage sampling module 3 may provide four single-ended input channels for four voltage signals to be input simultaneously.

Further, in this embodiment, please refer to fig. 5, the voltage sampling module 3 further includes two differential filter units, each of the differential filter units is electrically connected to two input channels of the ad 1115, and the four input channels are numbered as channel 0, channel 1, channel 2, and channel 3 from top to bottom, for example, as indicated in fig. 5, where the first differential filter unit is electrically connected to channel 0 and channel 1, and the second differential filter unit is electrically connected to channel 2 and channel 3. Taking the first differential filter unit as an example, the first differential filter unit comprises three second capacitors which are sequentially connected end to form a closed loop, one node of the first differential filter unit is connected to an analog ground, one end of one second capacitor is electrically connected with a channel 0 of the analog-to-digital conversion chip ADS1115, the other end of the other second capacitor is electrically connected with a channel 1 of the analog-to-digital conversion chip ADS1115, and the channel 0 and the channel 1 are connected through the differential filter unit, so that the channel 0 and the channel 1 can be used for inputting a differential input voltage, and the analog-to-digital conversion chip ADS1115 can input two groups of differential input voltages. The structure of the second differential filter unit is similar to that of the first differential filter unit, and can be understood by referring to the above description, and is not described herein again.

In the structure, the voltage dividing filter unit and the differential filter unit are alternatively arranged, so that the voltage sampling module 3 can have four-way single-ended input or two-way differential input, and the arrangement can be selected according to actual sampling requirements, so that the isolated voltage sampling circuit can meet diversified sampling requirements, and the applicability is wider.

Further, in this embodiment, please refer to fig. 6 in detail, the power module 4 includes a DC isolation power chip B0515S, the DC isolation power chip B0515S can provide a stable DC voltage for the control module 1 and the voltage sampling module 3 to stably operate, and the provided voltage is an isolation voltage, which can operate alone and does not interfere with other power supplies.

Further, in the present embodiment, please continue to refer to fig. 6, the power module 4 further includes a first voltage stabilizing unit and a second voltage stabilizing unit connected in parallel;

the voltage input end of the first voltage stabilizing unit is electrically connected with the voltage output end of the DC isolation power supply chip B0515S, the voltage output end is electrically connected with the control module 1 and is used for supplying power for the control module 1, and the DC isolation power supply chip B0515S outputs 12V isolation voltage and then supplies power to the control module 1 through the voltage reduction and stabilization effect of the first voltage stabilizing unit, namely, the MCU outputs 3.3V voltage to supply power for the MCU.

The voltage input end of the second voltage stabilizing unit is electrically connected with the voltage output end of the DC isolation power supply chip B0515S, the voltage output end is electrically connected with the voltage sampling module 3 and is used for supplying power for the voltage sampling module 3, and after the DC isolation power supply chip B0515S outputs 12V isolation voltage, the voltage is supplied to the voltage sampling module 3 through the voltage reduction and stabilization effect of the second voltage stabilizing unit, namely, the analog-to-digital conversion chip ADS1115 outputs 5V voltage to supply power for the analog-to-digital conversion chip ADS 1115. The voltage stabilizing unit structure can perform voltage reduction and stabilization on the isolation voltage output by the DC isolation power supply chip B0515S, so that the isolation voltage is converted into the working voltage of a corresponding component, and stable voltage output can be provided.

Further, in this embodiment, the first voltage stabilizing unit and the second voltage stabilizing unit are both linear voltage regulators LDO, which are low dropout linear voltage regulators, and are suitable for voltage stabilizing processes of chips with small voltage differences at input and output ends, and suitable for voltage stabilizing components of the MCU and the analog-to-digital conversion chip ADS 1115.

Further, in this embodiment, referring to fig. 7 in detail, the power module 4 further includes:

buck voltage reduction unit, Buck voltage reduction unit's voltage input end is used for inserting external voltage, and voltage output end is connected with DC isolation power chip B0515S's voltage input end electricity, and Buck voltage reduction unit is used for stepping down the required 5V input voltage of power to DC isolation power chip B0515S and communication isolation power with the 12V power supply of outside, and Buck voltage reduction unit has the accurate stable advantage of step-down.

In the description of the present disclosure, it is to be understood that the directions or positional relationships indicated by the directional terms such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal" and "top, bottom", etc., are generally based on the directions or positional relationships shown in the drawings for the convenience of description and simplicity of description, and in the case of not being described to the contrary, these directional terms are not intended to indicate and imply that the device or element so referred to must have a particular orientation or be constructed and operated in a particular orientation, and therefore, should not be considered as limiting the scope of the present disclosure.

Various other modifications and changes may be made by those skilled in the art based on the above-described technical solutions and concepts, and all such modifications and changes should fall within the scope of the claims of the present disclosure.

Claims (10)

1. An isolated voltage sampling circuit, comprising:

a control module;

the communication module is in communication connection with the control module and is used for communicating with external equipment;

the voltage sampling module comprises an input multiplexer for providing multiple input channels and a plurality of first resistors for voltage division, the resistance values of the first resistors are different, each input channel is connected with at least one first resistor, and the multiple input channels are connected with an analog ground after being connected with the first resistors; the signal output end of the voltage sampling module is electrically connected with the signal input end of the control module;

and the power supply module is respectively electrically connected with the control module and the voltage sampling module and used for supplying power.

2. The isolated voltage sampling circuit of claim 1, wherein the control module comprises an FM33 series MCU.

3. The isolated voltage sampling circuit of claim 1, wherein the communication module comprises:

an RS485 communication chip; the RS485 communication chip is in communication connection with the control module and is used for communicating with external equipment;

the communication isolation power supply is electrically connected with the RS485 communication chip and is used for supplying power to the RS485 communication chip.

4. The isolated voltage sampling circuit of claim 1, wherein the voltage sampling module comprises:

the device comprises an analog-to-digital conversion chip ADS1115, wherein four input channels of the analog-to-digital conversion chip ADS1115 are used for accessing four sampling voltages at most simultaneously; and the signal output end of the analog-to-digital conversion chip ADS1115 is electrically connected with the signal input end of the control module.

5. The isolated voltage sampling circuit of claim 4, wherein the voltage sampling module further comprises a voltage division filtering unit, the voltage division filtering unit comprising:

the second resistors are connected between the analog-to-digital conversion chip ADS1115 and the control module, and each input channel of the analog-to-digital conversion chip ADS1115 is connected to an analog ground through at least one second resistor;

the first capacitors are connected between the analog-to-digital conversion chip ADS1115 and the control module, and each input channel of the analog-to-digital conversion chip ADS1115 is connected to an analog ground through at least one first capacitor; and after the at least one second resistor is connected with the at least one first capacitor in parallel, one end of the at least one second resistor is connected with the single-path input channel, and the other end of the at least one second resistor is connected to the analog ground.

6. The isolated voltage sampling circuit according to claim 4, wherein the voltage sampling module further includes two differential filtering units, each differential filtering unit is electrically connected to two input channels of the analog-to-digital conversion chip ADS1115, each differential filtering unit includes three second capacitors sequentially connected end to form a closed loop, one node of the differential filtering unit is connected to an analog ground, one end of one of the second capacitors is electrically connected to one input channel of the analog-to-digital conversion chip ADS1115, and the other end of the one second capacitor is electrically connected to the other input channel of the analog-to-digital conversion chip ADS 1115.

7. The isolated voltage sampling circuit of claim 1, wherein the power module comprises a DC isolated power chip B0515S.

8. The isolated voltage sampling circuit of claim 7, wherein the power module further comprises a first voltage stabilization unit and a second voltage stabilization unit connected in parallel;

the voltage input end of the first voltage stabilizing unit is electrically connected with the voltage output end of the DC isolation power supply chip B0515S, and the voltage output end is electrically connected with the control module and used for supplying power to the control module;

and the voltage input end of the second voltage stabilizing unit is electrically connected with the voltage output end of the DC isolation power supply chip B0515S, and the voltage output end is electrically connected with the voltage sampling module and used for supplying power to the voltage sampling module.

9. The isolated voltage sampling circuit of claim 8, wherein the first voltage regulation unit and the second voltage regulation unit are both linear voltage regulators (LDOs).

10. The isolated voltage sampling circuit according to claim 7, 8 or 9, wherein the power module further comprises:

and the voltage input end of the Buck voltage reduction unit is used for accessing external voltage, and the voltage output end of the Buck voltage reduction unit is electrically connected with the voltage input end of the DC isolation power supply chip B0515S.

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