Self-adaptive voltage switching circuit for electric tool

Abstract

The utility model discloses a self-adaptive voltage switching circuit for an electric tool, which comprises a series control circuit, a parallel control circuit, a main circuit for detecting voltage and controlling a relay, and the relay for controlling the switching of the series control circuit and the parallel control circuit, the series control circuit comprises two stator coils which are connected in series, the parallel control circuit comprises two stator coils which are connected in parallel, and the zero line end of the power supply is connected with one wiring end of a motor of the electric tool; the live wire end of the power supply is connected with one of the series control circuit and the parallel control circuit, and the series control circuit and the parallel control circuit are both connected with the other wiring end of the electric tool motor. When the main circuit detects that the input voltage is high voltage, the relay is controlled to conduct the live wire end of the power supply, the series control circuit and the other wiring end of the motor; and when the main circuit detects that the input voltage is low voltage and the main circuit detects that the input voltage is high voltage, the relay is controlled to conduct the live wire end of the power supply, the parallel control circuit and the other wiring end of the motor.

Description

Technical Field

[0001] The utility model relates to a voltage switching circuit, in particular to an adaptive voltage switching circuit for electric tools. Background Art

[0002] Due to their high efficiency and precision, power tools have a wide range of uses, covering multiple fields from daily household maintenance to large-scale industrial production. Their uses cover scenarios such as home use, construction, car maintenance, and industrial production.

[0003] Existing AC power tools like angle grinders, electric drills, and other household appliances only support one voltage. Currently, there are two main voltages used worldwide: 100V-130V and 220-240V. 100V and 110-130V are classified as low voltage, such as those used in the United States, Japan, and on ships. Therefore, equipment designed for these low voltages prioritizes safety. 220-240V is considered high voltage, encompassing China's 220V, the UK's 230V, and many European countries, emphasizing efficiency.

[0004] Electric tools exported to different countries with different voltages must use different motors and related parts, which greatly increases the variety of materials and production costs of manufacturers. In addition, consumers will also be restricted by the non-universal voltage when purchasing or using related products, which will lead to increased costs. The incompatibility of the two will also limit their use occasions. Utility Model Content

[0005] Based on the disadvantage that electric tools in the prior art can only be connected to one input voltage, resulting in the inability to be universally used at home and abroad, the utility model provides an adaptive voltage switching circuit for electric tools.

[0006] The technical solution adopted by the present invention to solve the above technical problems is:

[0007] An adaptive voltage switching circuit for an electric tool comprises a series control circuit, a parallel control circuit, a main circuit for detecting voltage and controlling a relay, and a relay for controlling switching between the series control circuit and the parallel control circuit. The series control circuit comprises two stator coils connected in series, and the parallel control circuit comprises two stator coils connected in parallel. The ACL terminal of a power supply is connected to one terminal of a motor of the electric tool, the ACN terminal of the power supply is connected to one of the series control circuit and the parallel control circuit, and both the series control circuit and the parallel control circuit are connected to the other terminal of the motor of the electric tool. When the main circuit detects that the input voltage is high voltage, the control relay connects the ACN terminal of the power supply, the series control circuit, and the other terminal of the motor. When the main circuit detects that the input voltage is low voltage, the control relay connects the ACN terminal of the power supply, the parallel control circuit, and the other terminal of the motor.

[0008] Preferably, the series control circuit includes a stator coil L1, a relay K2, a relay K1 and a stator coil L2 connected in series, and the two ends of the series control circuit are respectively connected to the power supply ACN terminal and the other terminal of the motor, wherein the relay K1 and the relay K2 are closed to the normally closed end.

[0009] Preferably, two parallel diodes are provided between relay K2 and relay K1.

[0010] Preferably, the parallel control circuit includes a first circuit and a second circuit in parallel, the first circuit includes a relay K1 and a stator coil L2 connected in series, and the second circuit includes a stator coil L1 and a relay K2 connected in series, and the two ends of the parallel control circuit are respectively connected to the ACN terminal of the power supply and the other terminal of the motor, wherein the relay K1 and the relay K2 are closed to the normally open end.

[0011] Preferably, one of the terminals of the power supply is electrically connected to one of the terminals of the motor, and a speed regulator is provided between the two.

[0012] Preferably, the main circuit includes a bridge rectifier filter circuit for converting AC into DC.

[0013] Preferably, a current protector F1 is provided between the bridge rectifier filter circuit and the ACN terminal of the power supply.

[0014] Preferably, the bridge rectifier filter circuit includes a diode D1, a diode D2, a diode D3, a diode D4 and a capacitor C1. The AC voltage is rectified and filtered by the diode D1, the diode D2, the diode D3, the diode D4 and the capacitor C1, and then current limited by setting a resistor R1.

[0015] Preferably, after the 220V input voltage is rectified, the resistor R2 - resistor R3 - (pull-down resistor R4) - diode D5 - transistor Q1 is turned on, and at this time, relays K1 and K2 are closed to the normally closed end.

[0016] Preferably, after the 120V input voltage is rectified, the resistor R2 - resistor R3 - (pull-down resistor R4) - resistor R5 - transistor Q2 is turned on, and at this time, relays K1 and K2 are closed to the normally open end.

[0017] Compared with the prior art, the advantages of the present invention are as follows: the present application independently realizes the switching of the series or parallel circuit of the stator winding of the AC series-excited motor through the two relays K1 and K2 on the controller. When the two relays K1 and K2 recognize that the input voltage is high voltage, they switch to the series control circuit. When the two relays recognize that the input voltage is low voltage, they switch to the parallel control circuit. The low voltage and high voltage are adapted by switching the circuit, which reduces the cost of the power tool while enhancing its versatility. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be described in further detail below with reference to the accompanying drawings and preferred embodiments. However, those skilled in the art will appreciate that these drawings are drawn only for the purpose of explaining the preferred embodiments and should not be construed as limiting the scope of the present invention. Furthermore, unless otherwise specified, the drawings are merely schematic representations of the composition or structure of the depicted objects and may contain exaggerated representations. Furthermore, the drawings are not necessarily drawn to scale.

[0019] Figure 1 This is the circuit diagram of the utility model;

[0020] Figure 2 This is the circuit diagram of the utility model (the series circuit is bold);

[0021] Figure 3 The circuit diagram of the utility model (parallel circuit is bold);

[0022] Figure 4 This is the circuit diagram of the utility model (the bold frame is the relay control circuit);

[0023] Figure 5 This is the circuit diagram of the utility model (the relay is in the bold frame); DETAILED DESCRIPTION

[0024] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Those skilled in the art will appreciate that these descriptions are merely descriptive and exemplary and should not be construed as limiting the scope of protection of the present invention.

[0025] It should be noted that like reference numerals denote like items in the following drawings, and thus, once an item is defined in one drawing, it may not be further defined or explained in subsequent drawings.

[0026] Example

[0027] This embodiment mainly describes an adaptive voltage switching circuit for a power tool, as follows:

[0028] An adaptive voltage switching circuit for a power tool, such as Figure 1-5 As shown, it includes a series control circuit, a parallel control circuit, a main circuit for detecting voltage and controlling the relay, and a relay for controlling the switching of the series control circuit and the parallel control circuit. The series control circuit includes two stator coils connected in series and the parallel control circuit includes two stator coils connected in parallel. The ACL terminal of the power supply is connected to one terminal of the power tool motor, the ACN terminal of the power supply is connected to one of the series control circuit and the parallel control circuit, and the series control circuit and the parallel control circuit are both connected to the other terminal of the power tool motor. When the main circuit detects that the input voltage is high voltage, the control relay connects the ACN terminal of the power supply, the series control circuit and the other terminal of the motor; when the main circuit detects that the input voltage is low voltage, the main circuit detects that the input voltage is high voltage, the control relay connects the ACN terminal of the power supply, the parallel control circuit and the other terminal of the motor.

[0029] like Figure 1-5 As shown, the series control circuit includes a stator coil L1, a relay K2, and a relay K1 and a stator coil L2 connected in series. The two ends of the series control circuit are respectively connected to the power supply ACN terminal and the other terminal of the motor, wherein the relay K1 and the relay K2 are closed to the normally closed end.

[0030] like Figure 1-5 As shown, two diodes are connected in parallel between relay K2 and relay K1.

[0031] like Figure 1-5 As shown, the parallel control circuit includes a first circuit and a second circuit connected in parallel. The first circuit includes a relay K1 and a stator coil L2 connected in series, and the second circuit includes a stator coil L1 and a relay K2 connected in series. The two ends of the parallel control circuit are respectively connected to the power supply ACN terminal and the other terminal of the motor, wherein the relay K1 and the relay K2 are closed to the normally open end.

[0032] like Figure 1-5 As shown, one of the terminals of the power supply is electrically connected to one of the terminals of the motor and a speed regulator is provided between the two.

[0033] Preferably, the main circuit includes a bridge rectifier filter circuit for converting AC into DC.

[0034] Preferably, a current protector F1 is provided between the bridge rectifier filter circuit and the ACN terminal of the power supply.

[0035] Preferably, the bridge rectifier filter circuit includes a diode D1, a diode D2, a diode D3, a diode D4 and a capacitor C1. The AC voltage is rectified and filtered by the diode D1, the diode D2, the diode D3, the diode D4 and the capacitor C1, and then current limited by setting a resistor R1.

[0036] Preferably, after rectification, the 220V input voltage conducts resistor R2 - resistor R3 - (pull-down resistor R4) - diode D5 - transistor Q1. At this point, relays K1 and K2 are in the normally closed position, and transistor Q2 is turned off. Resistors R2 and R3 are connected in series and then in parallel with resistor R1. After passing through resistors R2 and R3, the input voltage is divided into two circuits: one circuit conducts diode D5 and transistor Q1, and the other circuit conducts resistor R5 and transistor Q2.

[0037] Preferably, after the 120V input voltage is rectified, the resistor R2 - resistor R3 - (pull-down resistor R4) - resistor R5 - transistor Q2 are connected. At this time, relays K1 and K2 are closed to the normally open end, and transistor Q1 is turned off. The two transistors Q1 and Q2 are used to control the two relays K1 and K2 to conduct the series control circuit or the parallel control circuit.

[0038] The resistance values ​​of the resistors are as follows (in ohms): R1 = 10K, R2 = 33K, R3 = 33K, R4 = 33K, and R5 = 10K. Two relays are set in the main circuit and connected in series with the resistor R1. The relay switches K1 and K2 are used to control the switching of the series / parallel control circuit. Figure 1 The two blocks in the figure are two relays.

[0039] The above is a detailed introduction to the titles provided by the utility model. Specific examples are used in this article to illustrate the principles and implementation methods of the utility model. The description of the above embodiments is only used to help understand the utility model and its core ideas. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the utility model, the utility model can also be improved and modified. These improvements and modifications also fall within the scope of protection of the claims of the utility model.

Claims

1. An adaptive voltage switching circuit for a power tool, characterized in that: It includes a series control circuit, a parallel control circuit, a main circuit for detecting voltage and controlling a relay, and a relay for controlling switching between the series control circuit and the parallel control circuit. The series control circuit includes two stator coils connected in series, and the parallel control circuit includes two stator coils connected in parallel. The ACL terminal of the power supply is connected to one terminal of the power tool motor, the ACN terminal of the power supply is connected to one of the series control circuit and the parallel control circuit, and the series control circuit and the parallel control circuit are both connected to the other terminal of the power tool motor. When the main circuit detects that the input voltage is high voltage, the control relay connects the ACN terminal of the power supply, the series control circuit and the other terminal of the motor; when the main circuit detects that the input voltage is low voltage, the control relay connects the ACN terminal of the power supply, the parallel control circuit and the other terminal of the motor.

2. The adaptive voltage switching circuit for a power tool according to claim 1, characterized in that: The series control circuit includes a stator coil L1, a relay K2, and a relay K1 and a stator coil L2 connected in series. The two ends of the series control circuit are respectively connected to the power supply ACN terminal and the other terminal of the motor, wherein the relay K1 and the relay K2 are closed to the normally closed end.

3. The adaptive voltage switching circuit for a power tool according to claim 2, characterized in that: Two parallel diodes are provided between relay K2 and relay K1.

4. The adaptive voltage switching circuit for a power tool according to claim 2, characterized in that: The parallel control circuit includes a first circuit and a second circuit connected in parallel. The first circuit includes a relay K1 and a stator coil L2 connected in series. The second circuit includes a stator coil L1 and a relay K2 connected in series. The two ends of the parallel control circuit are respectively connected to the power supply ACN terminal and the other terminal of the motor, wherein the relay K1 and the relay K2 are closed to the normally open end.

5. The adaptive voltage switching circuit for a power tool according to claim 1, characterized in that: One of the wiring terminals of the power supply is electrically connected to one of the wiring terminals of the motor, and a speed regulator is arranged between the two.

6. The adaptive voltage switching circuit for a power tool according to claim 4, characterized in that: The main circuit includes a bridge rectifier and filter circuit that converts AC to DC.

7. The adaptive voltage switching circuit for a power tool according to claim 6, characterized in that: A current protector F1 is provided between the bridge rectifier filter circuit and the ACN terminal of the power supply.

8. The adaptive voltage switching circuit for a power tool according to claim 7, characterized in that: The bridge rectifier and filter circuit includes diode D1, diode D2, diode D3, diode D4 and capacitor C1. The AC voltage is rectified and filtered by diode D1, diode D2, diode D3, diode D4 and capacitor C1, and then current is limited by setting resistor R1.

9. The adaptive voltage switching circuit for a power tool according to claim 8, characterized in that: After the 220V input voltage is rectified, the resistor R2 - resistor R3 - (pull-down resistor R4) - diode D5 - transistor Q1 are turned on. At this time, relays K1 and K2 are closed to the normally closed end.

10. The adaptive voltage switching circuit for a power tool according to claim 9, characterized in that: After the 120V input voltage is rectified, the resistor R2 - resistor R3 - (pull-down resistor R4) - resistor R5 - transistor Q2 is turned on. At this time, relays K1 and K2 are closed to the normally open end.

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