CN210183007U - Overcurrent protection circuit of direct current motor - Google Patents
Overcurrent protection circuit of direct current motor Download PDFInfo
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- CN210183007U CN210183007U CN201920841813.1U CN201920841813U CN210183007U CN 210183007 U CN210183007 U CN 210183007U CN 201920841813 U CN201920841813 U CN 201920841813U CN 210183007 U CN210183007 U CN 210183007U
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- resistor
- direct current
- overcurrent protection
- closed switch
- normally closed
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Abstract
The utility model discloses an overcurrent protection circuit of a direct current motor, which comprises a voltage input end, a voltage output end, a bipolar triode, a conduction element, a direct current motor, a coil and a normally closed switch; the conducting element comprises a first resistor, a second resistor, a third resistor, a fourth resistor and a fifth resistor, the voltage input end and the emitting electrode of the bipolar triode are connected between the first resistors, one end of the normally closed switch is connected to the first resistor and the first node between the third resistors, the other end of the normally closed switch is connected to the voltage output end, and the base electrode of the bipolar triode is connected to the third resistor and the second node between the fourth resistors. The utility model relates to a DC motor's overcurrent protection circuit has strengthened overcurrent protection circuit's sensitivity and reliability to DC motor's overcurrent protection has been improved.
Description
Technical Field
The utility model relates to an overcurrent protection circuit technical field especially relates to a DC motor's overcurrent protection circuit.
Background
Overcurrent protection is a protection mode in which a protection device is activated when a current exceeds a predetermined maximum value. When the current flowing through the protected original exceeds a preset value, the protection device is started, and the selectivity of action is ensured by time limit, so that the circuit breaker trips or gives an alarm signal. Overcurrent protection mainly includes two types of short-circuit protection and overload protection. The short-circuit protection is characterized by large setting current and instantaneous action. Electromagnetic current trips or relays, fuses are often used as short-circuit protection elements. The overload protection is characterized by small setting current and inverse time limit action. Thermal relays and time-delay electromagnetic current relays are commonly used as overload protection elements.
In the prior art, most direct current motors have rated current, and in order to ensure that the rated current is not exceeded, a fuse is usually arranged on a power supply line to prevent the direct current motors from being burnt due to overlarge current. However, the current response of the common fuse is slow, the protection effect is insensitive, and after the fuse is disconnected, a user needs to manually replace a new fuse to enable the direct current motor to work again, which is very troublesome.
SUMMERY OF THE UTILITY MODEL
Technical problem to be solved
The utility model aims to solve the problem that a DC motor's overcurrent protection circuit is provided, the sensitivity and the reliability of overcurrent protection circuit have been strengthened to DC motor's overcurrent protection has been improved.
(II) technical scheme
In order to achieve the above object, the present invention provides an overcurrent protection circuit for a dc motor, including a voltage input terminal, a voltage output terminal, a bipolar transistor, a conducting element, a dc motor, a coil and a normally closed switch;
the conducting element comprises a first resistor, a second resistor, a third resistor, a fourth resistor and a fifth resistor, an emitting electrode of the bipolar triode is connected between the voltage input end and the first resistor, one end of the normally closed switch is connected to a first node between the first resistor and the third resistor, the other end of the normally closed switch is connected with the voltage output end, a base electrode of the bipolar triode is connected to a second node between the third resistor and the fourth resistor, a collector electrode of the bipolar triode is connected with the second resistor, and one end of the normally closed switch is connected to a third node between the fourth resistor and the fifth resistor;
one end of the coil is connected with the second resistor, the other end of the coil is grounded, the positive pole of the direct current motor is connected with the voltage output end, and the negative pole of the direct current motor is grounded.
The overcurrent protection circuit is connected between the voltage input end and the direct current motor, an emitting electrode of the bipolar triode is connected to the voltage input end, a base electrode of the bipolar triode is connected to a second node between the third resistor and the fourth resistor, and a collector electrode of the bipolar triode is connected to the second resistor; one end of the third resistor is connected to a first node between the first resistor and the normally closed switch, when the direct current motor is normally powered on, the current flowing through the direct current motor is smaller than the rated current, no current passes through an emitting electrode of the bipolar triode, the bipolar triode is cut off, the coil is not powered, the normally closed switch is conducted, and the direct current motor normally works; when the current at the voltage input end is larger than the rated current, the overcurrent protection circuit starts to work, the emitter of the bipolar triode has the current to pass through, the current of the emitter of the bipolar triode flows into the collector of the bipolar triode, the coil L is electrified, the buzzer starts to give an alarm to a user, the normally closed switch is switched off, and the direct current does not input current, so that the direct current motor is protected.
Furthermore, a first diode for one-way conduction is connected between the second resistor and the coil, a second diode for one-way conduction is connected between the normally closed switch and the third node, and a third diode for one-way conduction is connected between the direct current motor and the third node.
Further, a buzzer for overcurrent alarm is connected in series between the first diode and the coil.
Further, the coil controls the on or off of the normally closed switch.
(III) advantageous effects
Compared with the prior art, the technical scheme of the utility model have following advantage: the utility model discloses utilize PNP type triode and relay to realize the overcurrent protection to DC motor, overcurrent protection circuit can be in DC motor's voltage input end and voltage output end between the electric current be greater than when rated current control PNP type triode switch on, and the electricity is gone up to the coil this moment, and then control normally closed switch disconnection to effectively protect DC motor. On the contrary, when the current of the direct current motor returns to the rated current again, the triode cannot be conducted, the direct current motor works normally again, the direct current motor is very sensitive, the power supply of the direct current motor can be restored without manual operation of a user, the operation is very convenient, and the direct current motor is effectively protected through the overcurrent protection circuit.
Drawings
Fig. 1 is a circuit diagram of an overcurrent protection circuit of a dc motor according to the present invention;
the corresponding part names for the various reference numbers in the figures are: vin is a voltage input end, Vout is a voltage output end, VT is a bipolar triode, a is a direct current motor, L is a coil, K is a normally closed switch, R1 is a first resistor, R2 is a second resistor, R3 is a third resistor, R4 is a fourth resistor, R5 is a fifth resistor, VD1 is a first diode, VD2 is a second diode, VD3 is a third diode, HA is a buzzer, 1 is a first node, 2 is a second node, and 3 is a third node.
Detailed Description
In this embodiment:
the following detailed description of the embodiments of the present invention is provided with reference to the accompanying drawings and examples. The following examples are intended to illustrate the invention, but are not intended to limit the scope of the invention.
As shown in fig. 1, an overcurrent protection circuit of a dc motor includes a voltage input terminal Vin, a voltage output terminal Vout, a bipolar transistor VT, a conduction element, a dc motor a, a coil L, and a normally-closed switch K; the conducting element comprises a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4 and a fifth resistor R5, an emitter of a bipolar transistor VT is connected between a voltage input end Vin and the first resistor R1, one end of a normally closed switch K is connected to a first node 1 between the first resistor R1 and the third resistor R3, the other end of the normally closed switch K is connected with a voltage output end Vout, a base of the bipolar transistor VT is connected to a second node 2 between the third resistor R3 and the fourth resistor R4, a collector of the bipolar transistor VT is connected with the second resistor R2, and one end of the normally closed switch K is connected to a third node 3 between the fourth resistor R4 and the fifth resistor R5; one end of the coil L is connected with the second resistor R2, the other end of the coil L is grounded, the positive pole of the direct current motor A is connected with the voltage output end Vout, and the negative pole of the direct current motor A is grounded.
A first diode VD1 for one-way conduction is connected between the second resistor R2 and the coil L, a second diode VD2 for one-way conduction is connected between the normally closed switch K and the third node 3, and a third diode VD3 for one-way conduction is connected between the direct current motor A and the third node 3; a buzzer HA for overcurrent alarm is connected in series between the first diode VD1 and the coil L; the coil L controls the on or off of the normally closed switch K.
Referring to fig. 1, the overcurrent protection circuit is connected between the voltage input terminal Vin and the dc motor a, the emitter of the bipolar transistor VT is connected to the voltage input terminal Vin, the base of the bipolar transistor VT is connected to the second node 2 between the third resistor R3 and the fourth resistor R4, and the collector of the bipolar transistor VT is connected to the second resistor R2; one end of the third resistor R3 is connected to a first node 1 between the first resistor R1 and the normally closed switch K, when the current motor A is normally electrified, the current flowing through the direct current motor A is smaller than the rated current, no current passes through an emitting electrode of the bipolar triode VT, the bipolar triode VT is cut off, the coil L is not electrified, the normally closed switch K is conducted, and the direct current motor A normally works; when the current at the voltage input end Vin is larger than the rated current, the overcurrent protection circuit starts to work at the moment, the current passes through the emitter of the bipolar triode VT, the current of the emitter of the bipolar triode VT flows into the collector of the bipolar triode VT, the coil L is electrified, the buzzer HA starts to give an alarm to a user, the normally-closed switch K is switched off, and the direct current A HAs no current input, so that the direct current motor A is protected, the first diode VD1 prevents the current from flowing back, the second diode VD2 prevents the current from flowing back to the voltage output end Vout, and the third diode VD3 prevents the current from flowing back to the direct current motor A; when the current of the direct current motor A returns to the rated current again, the bipolar transistor VT can not be conducted, the direct current motor A works normally again, the direct current motor A is very sensitive, and the power supply of the direct current motor A can be recovered without manual operation of a user.
Compared with the prior art, the technical scheme of the utility model have following advantage: the utility model discloses utilize PNP type triode and relay to realize the overcurrent protection to DC motor, overcurrent protection circuit can be in DC motor's voltage input end and voltage output end between the electric current be greater than when rated current control PNP type triode switch on, and the electricity is gone up to the coil this moment, and then control normally closed switch disconnection to effectively protect DC motor. On the contrary, when the current of the direct current motor returns to the rated current again, the triode cannot be conducted, the direct current motor works normally again, the direct current motor is very sensitive, the power supply of the direct current motor can be restored without manual operation of a user, the operation is very convenient, and the direct current motor is effectively protected through the overcurrent protection circuit.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of improvements and decorations can be made without departing from the technical principle of the present invention, and these improvements and decorations should also be regarded as the protection scope of the present invention.
Claims (4)
1. The utility model provides a direct current motor's overcurrent protection circuit which characterized in that: the device comprises a voltage input end (Vin), a voltage output end (Vout), a bipolar triode (VT), a conducting element, a direct current motor (A), a coil (L) and a normally closed switch (K);
the turn-on element includes a first resistor (R1), a second resistor (R2), a third resistor (R3), a fourth resistor (R4), and a fifth resistor (R5), an emitter of the bipolar transistor (VT) is connected between the voltage input terminal (Vin) and the first resistor (R1), one end of the normally closed switch (K) is connected to a first node (1) between the first resistor (R1) and the third resistor (R3), the other end of the normally closed switch (K) is connected with the voltage output end (Vout), the base of the bipolar transistor (VT) is connected to the second node (2) between the third resistor (R3) and the fourth resistor (R4), the collector of the bipolar transistor (VT) is connected with the second resistor (R2), one end of the normally closed switch (K) is connected to a third node (3) between the fourth resistor (R4) and the fifth resistor (R5);
one end of the coil (L) is connected with the second resistor (R2), the other end of the coil (L) is grounded, the positive pole of the direct current motor (A) is connected with the voltage output end (Vout), and the negative pole of the direct current motor (A) is grounded.
2. The overcurrent protection circuit for a dc motor according to claim 1, wherein: the second resistance (R2) with be connected with between coil (L) and be used for the first diode (VD1) of unidirectional conduction, normally closed switch (K) with be connected with between third node (3) and be used for the second diode (VD2) of unidirectional conduction, direct current motor (A) with be connected with between third node (3) and be used for the third diode (VD3) of unidirectional conduction.
3. The overcurrent protection circuit for a dc motor according to claim 2, wherein: and a buzzer (HA) for overcurrent alarm is connected in series between the first diode (VD1) and the coil (L).
4. The overcurrent protection circuit for a dc motor according to claim 2, wherein: the coil (L) controls the on or off of the normally closed switch (K).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920841813.1U CN210183007U (en) | 2019-06-05 | 2019-06-05 | Overcurrent protection circuit of direct current motor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920841813.1U CN210183007U (en) | 2019-06-05 | 2019-06-05 | Overcurrent protection circuit of direct current motor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN210183007U true CN210183007U (en) | 2020-03-24 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201920841813.1U Expired - Fee Related CN210183007U (en) | 2019-06-05 | 2019-06-05 | Overcurrent protection circuit of direct current motor |
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| CN (1) | CN210183007U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113471934A (en) * | 2021-06-28 | 2021-10-01 | 上海平高天灵开关有限公司 | Inverse time-lag overcurrent protection device of switch cabinet direct current motor loop |
-
2019
- 2019-06-05 CN CN201920841813.1U patent/CN210183007U/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113471934A (en) * | 2021-06-28 | 2021-10-01 | 上海平高天灵开关有限公司 | Inverse time-lag overcurrent protection device of switch cabinet direct current motor loop |
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| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20200324 Termination date: 20200605 |
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| CF01 | Termination of patent right due to non-payment of annual fee |