CN210608614U

CN210608614U - Low-frequency charging circuit and charging equipment with double voltage input automatic switching functions

Info

Publication number: CN210608614U
Application number: CN201921738859.7U
Authority: CN
Inventors: 叶远军; 王业占; 洪桂明; 刘洋洋
Original assignee: Shanghai Guangwei Electric and Tools Factory
Current assignee: Shanghai Guangwei Electric and Tools Factory
Priority date: 2019-10-16
Filing date: 2019-10-16
Publication date: 2020-05-22
Anticipated expiration: 2029-10-16

Abstract

The utility model provides a low frequency charging circuit and battery charging outfit of two voltage input automatic switch-overs, include: the system comprises an input control module, a low-frequency transformer, an input sampling module and a main control module; the low-frequency transformer comprises a primary coil and a secondary coil, the primary coil is provided with at least three nodes including a first node, a second node and a third node, and the second node is positioned between the first node and the third node; the secondary coil of the low-frequency transformer is used for supplying power to the accessed battery; the first input end of the input control module is used for being connected with a live wire, the second input end of the input control module is used for being connected with a zero line, the first output end of the input control module is connected with the first node, the second output end of the input control module is connected with the second node, the third output end of the input control module is connected with the third node, and the first input end is communicated with the first output end; the input sampling module is used for connecting the live wire and the zero line so as to sample the input voltage between the live wire and the zero line.

Description

Low-frequency charging circuit and charging equipment with double voltage input automatic switching functions

Technical Field

The utility model relates to a battery charging outfit especially relates to a low frequency charging circuit and battery charging outfit of two voltage input automatic switch-overs.

Background

Storage Battery (Storage Battery) is a device for directly converting chemical energy into electric energy, and the working principle of the Storage Battery is generally as follows: when the battery is charged, the internal active substance is regenerated by using external electric energy, the electric energy is stored into chemical energy, and the chemical energy is converted into electric energy again to be output when the battery needs to be discharged.

In the prior art, the input of a charging circuit of a storage battery is mainly a circuit consisting of a single transformer winding, and the charging circuit is simple. The input of the conventional charging circuit is generally narrow voltage range, which is not suitable for use in a plurality of countries, the circuit can only adapt to one mains voltage, different voltage ranges must be distinguished for use (for example, a charger with European standard voltage and a charger with American standard voltage are used for use), and as a result, the circuit is very dangerous, even if the input voltage range is carefully checked to prevent danger and explosion, the reliability, safety and operability of the charging circuit are greatly reduced, and short circuit, damage and danger are easily caused.

SUMMERY OF THE UTILITY MODEL

The utility model provides a low frequency charging circuit and battery charging outfit of two voltage input automatic switch-overs to the solution can only adapt to a mains voltage's problem.

According to the utility model discloses an aspect provides a low frequency charging circuit of two voltage input automatic switch-overs, include: the system comprises an input control module, a low-frequency transformer, an input sampling module and a main control module;

the low-frequency transformer comprises a primary coil and a secondary coil, the primary coil is provided with at least three nodes including a first node, a second node and a third node, and the second node is positioned between the first node and the third node; the secondary coil of the low-frequency transformer is used for supplying power to the accessed battery so as to charge the battery;

the first input end of the input control module is used for being connected with a live wire, the second input end of the input control module is used for being connected with a zero line, the first output end of the input control module is connected with the first node, the second output end of the input control module is connected with the second node, the third output end of the input control module is connected with the third node, and the first input end is communicated with the first output end;

the input sampling module is used for connecting the live wire and the zero line so as to sample the input voltage between the live wire and the zero line and feed back the input voltage to the main control module;

the main control module can be connected with the input control module to control the on-off of the second input end and the second output end and the on-off of the second input end and the third output end.

Optionally, the input sampling module includes an on-off processing device and a photoelectric coupler; the first internal power supply, the first end of the first side of the photoelectric coupler, the second end of the first side of the photoelectric coupler and the on-off processing device are sequentially conducted with the ground; the second internal power supply, the first end of the second side of the photoelectric coupler and the second end of the second side of the photoelectric coupler are sequentially conducted with the ground, and the first end of the second side of the photoelectric coupler is also connected with the main control module;

the on-off processing device is further connected to the live wire and can also control on-off of the first side and on-off of the second side of the photoelectric coupler.

Optionally, the input sampling module further includes a first diode, a second diode, a filter capacitor, a first sampling resistor, and a second sampling resistor;

the first end of the first diode is connected with the live wire, the first sampling resistor and the second sampling resistor are connected between the second end of the first diode and the ground after being connected in series, the first end of the second diode is connected with a zero line, the second end of the second diode is connected with the second end of the first diode in common, and the filter capacitor is connected between the first end of the first sampling resistor and the second end of the second sampling resistor in parallel;

the on-off processing device is specifically used for acquiring an input sampling voltage of a node between the first sampling resistor and the second sampling resistor.

Optionally, the input sampling module further includes a first resistor, a second resistor, and a third resistor;

the first resistor is connected between the on-off processing device and the first internal power supply, the second resistor is connected between the first internal power supply and the input end of the first side of the photoelectric coupler, and the third resistor is connected between the second internal power supply and the input end of the second side of the photoelectric coupler.

Optionally, the input control module includes a first triode, a first input relay, a second triode, and a second input relay;

the first input relay is connected between the second input end and the second output end, and the second input relay is connected between the second input end and the third output end; the first triode is connected with the first input relay, and the second triode is connected with the second input relay;

the main control module is connected with the base electrode of the first triode and the base electrode of the second triode.

Optionally, the low-frequency charging circuit further includes an output control module and an output sampling module;

the secondary coil is connected with the output control module and used for supplying power to the battery by utilizing the output control module;

the output control module is respectively connected with the output sampling module and the main control module.

Optionally, the output control module includes a third triode and an output relay;

the third triode is connected with the output relay, and the output relay is connected between the secondary coil and the battery;

the main control module is connected to the base electrode of the third triode, and the main control module is further connected with a first battery access end used for being connected with the positive electrode end of the battery.

Optionally, the output control module further includes a third triode and a fourth diode;

the first node on the second side of the secondary coil, the third triode, the output relay and the first battery access end are sequentially conducted;

a second node on a second side of the secondary winding is connected to a second battery access terminal for connection to the negative terminal of the battery;

and a third node at the second side of the secondary coil, the fourth diode, the output relay and the first battery access end are sequentially conducted.

Optionally, the output sampling module includes a third sampling resistor and a fourth sampling resistor, the third sampling resistor and the fourth sampling resistor are connected in series and then connected between a first battery access end for connecting the positive terminal of the battery and the ground, the main control module is connected to the output sampling voltage of a node between the third sampling resistor and the fourth sampling resistor, so as to determine whether the battery is connected to the output control module according to the output sampling voltage.

According to a second aspect of the present invention, there is provided a charging device comprising the low frequency charging circuit of the first aspect and the dual voltage input automatic switching related to the alternative.

The utility model provides an among double voltage input automatic switch's low frequency charging circuit and battery charging outfit, can automated inspection judge input voltage when with commercial power connection to the corresponding quantity coil of matching control low frequency transformer drops into operation, and then, matches in the voltage of different standards (for example European standard voltage and American standard voltage), the utility model discloses a charging circuit all can normally work, so, uses the utility model discloses afterwards, can need not consider regional and national grid voltage standard, and compatible strong, and need not the manual switch.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.

Fig. 1 is a first schematic structural diagram of a low-frequency charging circuit with dual voltage inputs for automatic switching according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a low-frequency charging circuit with dual voltage inputs for automatic switching according to an embodiment of the present invention;

fig. 3 is a third schematic structural diagram of a low-frequency charging circuit with dual voltage inputs for automatic switching according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a low-frequency charging circuit with dual voltage inputs for automatic switching according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of a low-frequency charging circuit with dual voltage inputs for automatic switching according to an embodiment of the present invention;

fig. 6 is a circuit diagram of a low-frequency charging circuit with dual voltage inputs for automatic switching according to an embodiment of the present invention.

Description of reference numerals:

1-input control module;

2-a low frequency transformer;

3-input sampling module;

31-on-off processing means;

32-a photo coupler;

4-a main control module;

5-a battery;

6-an output control module;

7-output sampling module;

d1 — first diode;

d2 — second diode;

EC1 — filter capacitance;

r11 — first sampling resistor;

r12 — second sampling resistor;

r13 — third sampling resistor;

r14 — fourth sampling resistor;

r21 — first resistance;

r22 — second resistance;

r23 — third resistance;

q1-first triode;

q2-second transistor;

k1 — first input relay;

k2 — second input relay;

k4 — third input relay;

r31 — first current limiting resistor;

r32 — second current limiting resistor;

r4-resistance;

d3 — third diode;

d4 — fourth diode;

q3-third transistor;

q4-fourth transistor;

k3-output relay;

v1 — first internal power supply;

v2 — second internal power supply.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

The terms "first," "second," "third," "fourth," and the like in the description and in the claims, as well as in the drawings, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

The technical solution of the present invention will be described in detail with specific examples. The following several specific embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments.

Fig. 1 is a first schematic structural diagram of a low-frequency charging circuit with dual voltage inputs for automatic switching according to an embodiment of the present invention.

Referring to fig. 1, the low frequency charging circuit with dual voltage inputs for automatic switching includes: the device comprises an input control module 1, a low-frequency transformer 2, an input sampling module 3 and a main control module 4.

The circuit related to the embodiment can be applied to products such as a charger and a power supply.

The low-frequency transformer 2 comprises a primary coil and a secondary coil, wherein the primary coil is provided with at least three nodes, including a first node, a second node and a third node, and the second node is positioned between the first node and the third node; and the secondary coil of the low-frequency transformer is used for supplying power to the accessed battery so as to charge the battery.

The second node is located between the first node and the third node, when the second node is connected to the zero line, the part of the primary coil which is put into use is the part between the first node and the second node, and when the third node is connected to the zero line, the part of the primary coil which is put into use is the part between the first node and the third node.

In a specific example, the number of windings is one or more, i.e., at least one.

In this embodiment, a first input end of the input control module 1 is used for connecting a live wire, in fig. 1, an L end can be understood as one end used for accessing the live wire, a second input end of the input control module 1 is used for connecting a zero line, and in fig. 1, an N end can be understood as one end used for connecting the zero line; a first output end of the input control module 1 is connected with the first node, a second output end is connected with the second node, a third output end is connected with the third node, and the first input end is conducted with the first output end;

the input sampling module 3 is configured to connect the live line and the zero line to sample an input voltage between the live line and the zero line; this input voltage is understood to be the input voltage of the mains.

The main control module 4 is configured to:

when the input voltage is lower than a preset first threshold value, controlling the second input end to be conducted with the second output end; further, it may be matched to the input of a mains voltage, e.g. 120 VAC;

when the input voltage is higher than the first threshold value, controlling the second input end to be conducted with the third output end; further, it may be matched to another mains voltage, for example, the input of 120 VAC.

In the above embodiment, when the charging circuit is connected with a mains supply, the input voltage can be automatically detected and judged, and the corresponding number of coils of the low-frequency transformer are matched and controlled to be put into use, so that the charging circuit can normally work when being matched with voltages of different standards (such as European standard voltage and American standard voltage), and therefore after the charging circuit is used, the regional and national power grid voltage standards do not need to be considered, compatibility is high, and manual switching is not needed.

In addition, the present embodiment is not limited to matching of two standards, and may also match three or more standards, and correspondingly, in addition to the first node, the second node, and the third node, any number of nodes such as the fourth node, the fifth node, and the like, and corresponding sampling and control circuit portions may be arranged, and further, switching between any two standards may be applied to the above-mentioned embodiments.

The input sampling module 3 can be any circuit module capable of collecting voltage between the live wire and the zero line and feeding back the voltage to the main control module 4, and a signal fed back to the main control module 4 can be a digital signal or an analog voltage signal.

In the present embodiment, the output voltage range may be, for example, 6 volts to 72 volts.

Fig. 2 is a schematic structural diagram of a low-frequency charging circuit with dual voltage inputs for automatic switching according to an embodiment of the present invention.

In one embodiment, referring to fig. 2, the input sampling module 3 includes an on-off processing device 31 and a photo coupler 32.

The first internal power supply V1, the first end of the first side of the photoelectric coupler 32, the second end of the first side of the photoelectric coupler 32, the on-off processing device 31 and the ground are sequentially conducted; the second internal power source V2, the first end of the second side of the photoelectric coupler 32, and the second end of the second side of the photoelectric coupler 32 are sequentially connected to ground, and the first end of the second side of the photoelectric coupler 32 is further connected to the main control module.

Wherein said on-off handling means 31 are further connected to said live line for:

when the input voltage is lower than the first threshold, controlling the first side and the second side of the photoelectric coupler 32 to be non-conductive, so as to send a first signal to the main control module 4, so that the main control module 4 controls the second input end to be conductive with the second output end;

when the input voltage is higher than the first threshold value, the first side and the second side of the photoelectric coupler 32 are controlled to be conducted, so that a second signal is sent to the main control module 4, and the main control module controls the second input end to be conducted with the third output end.

The first signal and the second signal can be understood as any signals that can enable the main control module 4 to execute the corresponding function when the input voltage is lower than the first threshold value; it can be an analog voltage signal, and it is not excluded that the analog voltage signal is converted into a digital signal and then fed back to the main control module 4.

The on-off processing device 31 may also be characterized as an Integrated chip or an IC (Integrated circuit chip), and may be used to accurately determine the input voltage range by comparing with a high-precision Integrated chip.

In a specific implementation process, the input ac power can be rectified and filtered, and then the corresponding voltage information is sampled by the sampling resistor, so that the input sampling module 3 further includes a first diode D1, a second diode D2, a filter capacitor EC1, a first sampling resistor R11, and a second sampling resistor R12.

The first end of the first diode D1 is connected to the live wire, the first sampling resistor R11 and the second sampling resistor R12 are connected in series and then connected between the second end of the first diode D1 and the ground, the first end of the second diode D2 is connected to the zero line, the second end of the second diode D2 is connected in common with the second end of the first diode D1, that is: both connected to a first end of a first sampling resistor R11, the filter capacitor EC1 is connected in parallel between a first end of the first sampling resistor R11 and a second end of the second sampling resistor R12;

the on-off processing device 31 is specifically configured to collect an input sampling voltage at a node between the first sampling resistor R11 and the second sampling resistor R12, so as to characterize the input voltage by using the input sampling voltage, and is configured to:

when the input sampling voltage is lower than the voltage value corresponding to the first threshold, controlling the first side and the second side of the photoelectric coupler 32 to be non-conductive, so as to send the first signal to the main control module 4;

and when the input sampling voltage is higher than the voltage value corresponding to the first threshold, controlling the first side and the second side of the photoelectric coupler 32 to be both conducted so as to send the second signal to the main control module 4.

In a specific implementation process, the input sampling module 3 further includes a first resistor R21, a second resistor R22, and a third resistor R23;

the first resistor R21 is connected between the on-off processing device 31 and the first internal power source V1, the second resistor R22 is connected between the first internal power source V1 and the input terminal of the first side of the photocoupler 32, and the third resistor R23 is connected between the second internal power source V2 and the input terminal of the second side of the photocoupler 32.

In a specific example, once L and N have access to the city, the utility power is assumed to be 120VAC in american standard, at this time, the rectification of the first diode D1 and the second diode D2 is filtered by the filter capacitor EC1, so as to obtain smooth direct current to divide the voltage of the first sampling resistor R11 and the second sampling resistor R12, the designed divided voltage value of the first sampling resistor R11 and the second sampling resistor R12 can be above 140VAC, because 120VAC inputs the final divided voltage of 2.5V to compare with the on-off processing device 31, the pins at the two ends of the on-off processing device 31 can be in a high-resistance state when the on-off processing device 31 inputs the low voltage of 2.5V, at this time, no current flows through the first resistor R21 and the second resistor R22 from the voltage of the first internal power source V1, therefore, the first side of the photoelectric coupler 32 is not conducted, the second side of the photoelectric coupler 32 is not conducted, at the moment, electricity of the third resistor directly flows into the main control module 4, and the main control module 4 detects that the high potential is input by default into 120 VAC.

Fig. 3 is a third schematic diagram of the low-frequency charging circuit with dual voltage inputs for automatic switching according to an embodiment of the present invention.

Referring to fig. 3, in one embodiment, the input control module 1 includes a first transistor Q1, a first input relay K1, a second transistor Q2, and a second input relay K2.

The first input relay K1 is connected between the second input end and the second output end, so that a zero line can be connected to a second node after the first input relay K1 is switched on, the second input relay K2 is connected between the second input end and the third output end, and the zero line can be connected to a third node after the second input relay K2 is switched on; the first triode Q1 is connected with the first input relay K1, and the second triode Q2 is connected with the second input relay K2.

The main control module 4 is connected to the base of the first transistor Q1 and the base of the second transistor Q2, and is configured to:

if a first signal generated when the input voltage is lower than the first threshold value is received, the first triode Q1 is controlled to be switched on, and the second triode Q2 is switched off, so that the first input relay K1 switches on the second input end and the second output end;

if a second signal generated when the input voltage is higher than the first threshold value is received, the second triode Q2 is controlled to be switched on, and the first triode Q1 is switched off, so that the second input relay K2 switches on the second input end and the third output end.

Fig. 4 is a fourth schematic diagram of the low-frequency charging circuit with dual voltage inputs for automatic switching according to an embodiment of the present invention.

Referring to fig. 4, in an embodiment, the low frequency charging circuit further includes an output control module 6 and an output sampling module 7.

The secondary coil is connected with the output control module 6 and used for supplying power to the battery by utilizing the output control module.

The output control module 6 is respectively connected with the output sampling module 7 and the main control module 4, and is configured to: when the battery 5 is detected to be connected to the output control module 6, the conduction between the secondary coil and the battery 5 is controlled; and when the battery 5 is not connected to the output control module 6, controlling the secondary coil and the battery 5 to be not conducted.

As can be seen, in the above embodiment, the external power supply may be controlled only when the battery 5 is accessed.

In a specific implementation process, the output control module 6 includes a third transistor Q3 and an output relay K3.

The third triode Q3 is connected with the output relay K3, and the output relay K3 is connected between the secondary coil and the battery 5; the main control module 4 is connected to the base of the third triode Q3, and the main control module 4 is further connected to a first battery access end for connecting the positive terminal of the battery, and is configured to:

if the voltage of the battery access end is greater than a preset second threshold value, controlling the third triode to be conducted so that the output relay conducts the secondary coil and the battery;

and if the voltage of the battery access end is smaller than the second threshold value, controlling the third triode to be turned off.

The first battery access referred to above is understood to be the end for connecting the positive pole of the battery 5, which can be characterized as BAT +, and the second battery access is understood to be the end for connecting the negative pole of the battery 5, which can be characterized as BAT-.

The second threshold is understood to be any threshold capable of distinguishing a voltage after the battery is connected from a voltage when the battery is not connected, and can be determined arbitrarily according to theory and limited experiments.

The output control module 6 further includes a third transistor D3 and a fourth diode D4.

The first node on the second side of the secondary coil, the third triode D3, the output relay K3 and the first battery access end are sequentially conducted; a second node on a second side of the secondary winding is connected to a second battery access terminal for connection to the negative terminal of the battery; the third node on the second side of the secondary coil, the fourth diode D4, the output relay K3 and the first battery access terminal are sequentially conducted.

Furthermore, the third diode D3 and the fourth diode D4 can rectify the output power supply, and then supply the rectified power to the first battery connection terminal and the second battery connection terminal.

In a specific implementation process, the output sampling module 7 includes a third sampling resistor R13 and a fourth sampling resistor R14, the third sampling resistor R13 and the fourth sampling resistor R14 are connected in series and then connected between a first battery access terminal for connecting the positive terminal of the battery and the ground, and the main control module is connected to the output sampling voltage of a node between the third sampling resistor R13 and the fourth sampling resistor R14, so as to determine whether the battery 5 is connected to the output control module 6 according to the output sampling voltage.

The main control module 4 may be any circuit module capable of receiving a sampling signal and controlling on/off of a corresponding transistor, for example, an MCU may be adopted, where the MCU is specifically a Microcontroller Unit, and may also be characterized as a micro control Unit, a microprocessor, and the like.

It can be understood that the embodiments shown in fig. 1 to 5 above are combined to produce a solution.

Wherein the on-off processing device 31 may be characterized by IC1, the photocoupler 32 by PC1, the voltage of the first internal power supply by VCC, the low frequency transformer 2 by T1, and the voltage of the second internal power supply may be + 5V.

The circuit working condition must ensure that the input power supply can normally work, once the live wire and the zero wire are connected with the city, if the city is 120VAC, the first diode D1 and the second diode D2 diode are rectified and filtered through the filter capacitor EC1, the smooth direct current is obtained to be supplied to the first sampling resistor R11 and the second sampling resistor R12 for voltage division, the first sampling resistor R11 and the second sampling resistor R12 are designed to have the voltage division value of more than 140VAC, because the voltage division of 2.5V is finally carried out by the 120VAC input, the first sampling resistor R11 and the second sampling resistor R12 are compared with the 3 pin of the on-off processing device IC1, when the 3 pin of the on-off processing device IC1 is not connected with 2.5V, the 1 pin and the 2 pin of the on-off processing device IC1 are in a high-resistance state, the VCC voltage flows through the first resistor R21 and the second resistor R22, the PC1 is not connected, and the 1 pin, 2 pin and 4 of the photoelectric coupler PC1 are not connected, when the low-frequency transformer T is in a high-impedance state, the third resistor R23 directly flows into a pin 5 of the MCU in the main control module 4, the pin 5 of the MCU defaults to 120VAC input when detecting high potential, a pin 7 of the on-off processing device IC1 sends a level signal to drive the first triode Q1 through the current-limiting resistor R31, the base of the first triode Q1 is provided with a driving current, a collector and an emitter are conducted, the first triode Q1 is conducted, a coil of the first input relay K1 is conducted to generate a magnetic field, so that a pin 4 and a pin 5 of the first input relay K1 are triggered and closed, a pin 4 and a pin 5 of the first input relay K1 are triggered and closed to form a loop, so that the low-frequency transformer T1 works, a secondary side of the low-frequency transformer T works while a secondary side of the low-frequency transformer T simultaneously generates low-voltage alternating current output, the low-voltage alternating current output is rectified into a direct current output relay K, the premise that the output relay K3 works is that the battery is connected, so that the third sampling resistor R13 and the fourth sampling resistor R14 divide a battery access signal (namely, output sampling voltage), and when the 2 pins of the MCU receive the signal, the 2 pins of the MCU send out a charging signal to open the third triode to enable the output relay K3 to be conducted and output.

On the contrary, if the input power is 220VAC which is higher than the preset 140VAC voltage, the divided voltage of pin 1 of the on-off processing device IC1 is higher than 2.5V to immediately turn on the on-off processing device IC1, the on-off processing device IC1 is immediately turned on and forms a loop through the on-off processing device IC1 through the photocoupler PC1 to generate current, the photocoupler PC1 causes pin 3 and pin 4 to be pulled down to low potential of the low-resistance photocoupler PC1, pin 5 of the MCU detects the low potential at this time, the MCU can default that pin 8 sends out a level signal to drive the second triode Q7 through the second current limiting resistor R32, the collector and the emitter of the second triode Q2 have driving current to be turned on, the second triode Q2 is turned on to cause the coil of the second input relay K2 to be turned on to generate a magnetic field to trigger the pin 4 and the pin 5 of the second input relay K2 to be closed, the pin 4 and the pin 5 of the second input relay K2 form a loop to trigger the low-frequency transformer T1 to, the primary side of the low-frequency transformer T1 works and the secondary side of the low-frequency transformer T1 simultaneously generates low-voltage alternating current output, and the low-voltage alternating current output is rectified into direct current through a third diode D3 and a fourth diode D4 to charge the battery through an output relay K3.

Furthermore, in the embodiment shown in fig. 6, the input control module 1 may further include: a fourth triode Q4 and a third input relay K4, a base of the fourth triode Q4 may be connected to the MCU in the main control module 4 through a third current limiting resistor R33, two ends of the third input relay K4 are respectively connected to the zero line and a fourth node in the primary coil of the low frequency transformer T1, and the fourth node is located between the first node and the second node, or between the second node and the third node. Furthermore, the MCU can control the fourth transistor Q4 to be turned on, so that the third input relay K4 is turned on, and a part of the coil between the first node and the fourth node in the primary coil of the low frequency transformer T1 is used, and the operation principle thereof can be understood with reference to the operation principle of the first transistor Q1, the second transistor Q2, the first input relay K1 and the second input relay K2, which can be matched with the matched input voltage for use.

It can be seen that, any number of relays and triodes are disposed on the input side of the low-frequency transformer T1, and the relays are connected to corresponding nodes of the primary coil of the low-frequency transformer T1, which does not depart from the description of the present embodiment.

In the embodiment shown in fig. 6, a resistor R4 is further connected between the base of the third transistor Q3 and the MCU.

Therefore, in the specific implementation process, independent sorting filtering can be adopted for feedback, and the comparison is carried out by combining a high-precision integrated block to judge the input voltage range. Can automated inspection judge input voltage when being connected with the commercial power, do the judgement to the signal through keeping apart opto-coupler feedback singlechip, also send corresponding switching signal simultaneously and give input switching relay, make the charger no matter be european standard voltage or American standard voltage and even all normal work of other national input voltages of the whole world, this implementation process can accomplish energy-efficiently, and regional and national grid voltage need not considered to use convenient safety, but the compatibility need not the manual work by force to switch.

The embodiment also provides a charging device comprising the low-frequency charging circuit with the automatic switching function of the double-voltage input, which is related to the above alternative scheme.

In summary, in the low-frequency charging circuit and the charging device with dual-voltage input automatic switching provided by this embodiment, when connected to the mains supply, the input voltage can be automatically detected and determined, and the corresponding number of coils of the low-frequency transformer are matched and controlled to be put into use, and further, the charging circuit of this embodiment can normally work when matched with voltages of different standards (for example, european standard voltage and american standard voltage).

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.

Claims

1. A kind of dual voltage input automatic switching low frequency charging circuit, characterized by that, comprising: the system comprises an input control module, a low-frequency transformer, an input sampling module and a main control module;

2. The low frequency charging circuit of claim 1, wherein the input sampling module comprises an on-off processing device and an opto-coupler; the first internal power supply, the first end of the first side of the photoelectric coupler, the second end of the first side of the photoelectric coupler and the on-off processing device are sequentially conducted with the ground; the second internal power supply, the first end of the second side of the photoelectric coupler and the second end of the second side of the photoelectric coupler are sequentially conducted with the ground, and the first end of the second side of the photoelectric coupler is also connected with the main control module;

3. The low frequency charging circuit of claim 2, wherein the input sampling module further comprises a first diode, a second diode, a filter capacitor, and a first sampling resistor and a second sampling resistor;

4. The low frequency charging circuit of claim 2, wherein the input sampling module further comprises a first resistor, a second resistor, and a third resistor;

5. The low-frequency charging circuit according to any one of claims 1 to 4, wherein the input control module comprises a first triode, a first input relay, a second triode and a second input relay;

6. The low-frequency charging circuit according to any one of claims 1 to 4, further comprising an output control module and an output sampling module;

7. The low frequency charging circuit of claim 6, wherein the output control module comprises a third transistor and an output relay;

8. The low frequency charging circuit of claim 7, wherein the output control module further comprises a third transistor and a fourth diode;

9. The low-frequency charging circuit according to claim 6, wherein the output sampling module includes a third sampling resistor and a fourth sampling resistor, the third sampling resistor and the fourth sampling resistor are connected in series and then connected between a first battery connection terminal for connecting the positive terminal of the battery and ground, and the main control module is connected to an output sampling voltage at a node between the third sampling resistor and the fourth sampling resistor, so as to determine whether the battery is connected to the output control module according to the output sampling voltage.

10. A charging device comprising the dual voltage input auto-switching low frequency charging circuit of any one of claims 1 to 9.